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[Commit-gnuradio] [gnuradio] 06/06: digital: Added lots and lots of exam


From: git
Subject: [Commit-gnuradio] [gnuradio] 06/06: digital: Added lots and lots of examples for overhauled packet format
Date: Wed, 15 Jun 2016 04:11:15 +0000 (UTC)

This is an automated email from the git hooks/post-receive script.

jcorgan pushed a commit to branch packet3
in repository gnuradio.

commit b9c0d10fff4e18bd0fb7d88c8ca5d26d00af3181
Author: Tom Rondeau <address@hidden>
Date:   Tue Jun 14 10:45:03 2016 -0700

    digital: Added lots and lots of examples for overhauled packet format
---
 docs/doxygen/other/components.dox                  |    1 +
 gr-digital/examples/packet/README                  |    3 +
 gr-digital/examples/packet/burst_tagger.grc        | 1160 +++++
 .../packet/example_corr_est_and_clock_sync.grc     | 3068 ++++++++++++++
 .../packet/example_corr_est_and_phase_sync.grc     | 3474 +++++++++++++++
 gr-digital/examples/packet/formatter_crc.grc       |  958 +++++
 gr-digital/examples/packet/formatter_ofdm.grc      | 1157 +++++
 .../examples/packet/packet_loopback_hier.grc       | 4442 ++++++++++++++++++++
 gr-digital/examples/packet/packet_rx.grc           | 1895 +++++++++
 gr-digital/examples/packet/packet_tx.grc           | 1787 ++++++++
 gr-digital/examples/packet/simple_bpsk_tx.grc      | 3071 ++++++++++++++
 .../examples/packet/transmitter_sim_hier.grc       | 2313 ++++++++++
 gr-digital/examples/packet/tx_stage0.grc           |  286 ++
 gr-digital/examples/packet/tx_stage1.grc           |  284 ++
 gr-digital/examples/packet/tx_stage2.grc           |  494 +++
 gr-digital/examples/packet/tx_stage3.grc           |  445 ++
 gr-digital/examples/packet/tx_stage4.grc           | 1948 +++++++++
 gr-digital/examples/packet/tx_stage5.grc           | 2017 +++++++++
 gr-digital/examples/packet/tx_stage6.grc           | 2264 ++++++++++
 gr-digital/examples/packet/tx_stage6a.grc          | 2368 +++++++++++
 gr-digital/examples/packet/uhd_packet_rx.grc       | 4083 ++++++++++++++++++
 gr-digital/examples/packet/uhd_packet_rx_tun.grc   | 4143 ++++++++++++++++++
 gr-digital/examples/packet/uhd_packet_tx.grc       | 3293 +++++++++++++++
 gr-digital/examples/packet/uhd_packet_tx_tun.grc   | 3236 ++++++++++++++
 24 files changed, 48190 insertions(+)

diff --git a/docs/doxygen/other/components.dox 
b/docs/doxygen/other/components.dox
index 1e98beb..564085f 100644
--- a/docs/doxygen/other/components.dox
+++ b/docs/doxygen/other/components.dox
@@ -22,6 +22,7 @@ All our in-tree components have their own top-level 
documentation:
 \li \subpage page_channels
 \li \subpage page_ctrlport
 \li \subpage page_digital
+\li \subpage page_packet_comms
 \li \subpage page_fcd
 \li \subpage page_fec
 \li \subpage page_fft
diff --git a/gr-digital/examples/packet/README 
b/gr-digital/examples/packet/README
new file mode 100644
index 0000000..6051c11
--- /dev/null
+++ b/gr-digital/examples/packet/README
@@ -0,0 +1,3 @@
+See the Packet Communications page in the GNU Radio manual.
+
+http://gnuradio.org/doc/doxygen
diff --git a/gr-digital/examples/packet/burst_tagger.grc 
b/gr-digital/examples/packet/burst_tagger.grc
new file mode 100644
index 0000000..28edee1
--- /dev/null
+++ b/gr-digital/examples/packet/burst_tagger.grc
@@ -0,0 +1,1160 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Tue Apr  5 13:57:36 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>top_block</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(168, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_stream_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(432, 99)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_stream_to_tagged_stream_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>"packet_len"</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>packet_len</key>
+      <value>16*10</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_throttle</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(248, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_throttle_0</value>
+    </param>
+    <param>
+      <key>ignoretag</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_vector_source_x</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_vector_source_x_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tags</key>
+      <value>[]</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>vector</key>
+      <value>[1,1,1,1,1,1,1,1,-1,-1,-1,-1,-1,-1,-1,-1]</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_burst_shaper_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(696, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_burst_shaper_xx_0</value>
+    </param>
+    <param>
+      <key>insert_phasing</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>length_tag_name</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>post_padding</key>
+      <value>20</value>
+    </param>
+    <param>
+      <key>pre_padding</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>window</key>
+      <value>firdes.window(firdes.WIN_HANN, 50, 0)</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_burst_shaper_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(696, 203)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_burst_shaper_xx_0_0</value>
+    </param>
+    <param>
+      <key>insert_phasing</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>length_tag_name</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>post_padding</key>
+      <value>20</value>
+    </param>
+    <param>
+      <key>pre_padding</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>window</key>
+      <value>firdes.window(firdes.WIN_HANN, 50, 0)</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(968, 83)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>With Phasing Symbols</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>512</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>1.5</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-1.5</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(968, 211)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>Without Phase Symbols</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>512</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>1.5</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-1.5</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_stream_to_tagged_stream_0</source_block_id>
+    <sink_block_id>digital_burst_shaper_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_stream_to_tagged_stream_0</source_block_id>
+    <sink_block_id>digital_burst_shaper_xx_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_throttle_0</source_block_id>
+    <sink_block_id>blocks_stream_to_tagged_stream_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_vector_source_x_0</source_block_id>
+    <sink_block_id>blocks_throttle_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_burst_shaper_xx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_burst_shaper_xx_0_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/example_corr_est_and_clock_sync.grc 
b/gr-digital/examples/packet/example_corr_est_and_clock_sync.grc
new file mode 100644
index 0000000..dfd1959
--- /dev/null
+++ b/gr-digital/examples/packet/example_corr_est_and_clock_sync.grc
@@ -0,0 +1,3068 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Tue Apr  5 13:57:36 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>example_corr_est_and_clock_sync</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(264, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>ac</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>map(lambda x: int(x), 
list(digital.packet_utils.default_access_code))</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 595)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>ac_hex</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[0xac, 0xdd, 0xa4, 0xe2, 0xf2, 0x8c, 0x20, 0xfc]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(584, 531)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.22</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(768, 531)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>filt_delay</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1+(len(rrc_taps)-1)/2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 563)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>freq_off</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Freq. Off.</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>-0.25</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.0001</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>0.25</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(960, 523)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_const</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(672, 531)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mark_delay</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>mark_delays[sps]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value>Tag Marking Delay for 
+Corr Est block, indexed
+by sps.
+
+Found empirically.</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 675)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mark_delays</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[0, 0, 34, 56, 87, 119]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_modulate_vector</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>data</key>
+      <value>ac_hex</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>[1]</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(960, 651)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>modulated_sync_word</value>
+    </param>
+    <param>
+      <key>mod</key>
+      <value>rxmod</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1104, 451)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>-50</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(176, 435)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>noise</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Noise Power</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>-50</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 435)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>path_loss</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Path Loss (dB)</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>5</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>140</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1120, 523)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rrc_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>11*sps</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(960, 387)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_psf_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>11*sps*nfilts</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>sps*nfilts</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(672, 595)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rxmod</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.generic_mod(hdr_const, False, sps, True, eb, False, 
False)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(168, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>10e3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(512, 531)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(176, 563)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>time_off</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Time Off.</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0.9999</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.00001</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>1.0001</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_add_const_vxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(368, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_add_const_vxx_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_complex_to_mag_squared</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(528, 457)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_complex_to_mag_squared_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_multiply_const_vxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_multiply_const_vxx_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_stream_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(664, 99)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_stream_to_tagged_stream_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>"packet_len"</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>packet_len</key>
+      <value>len(ac)+16</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_throttle</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_throttle_0</value>
+    </param>
+    <param>
+      <key>ignoretag</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_vector_source_x</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_vector_source_x_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tags</key>
+      <value>[]</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>vector</key>
+      <value>[1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0] + ac</value>
+    </param>
+  </block>
+  <block>
+    <key>channels_channel_model</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>block_tags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>epsilon</key>
+      <value>time_off</value>
+    </param>
+    <param>
+      <key>freq_offset</key>
+      <value>freq_off</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 203)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>channels_channel_model_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>noise_voltage</key>
+      <value>sps * 10.0**(noise/10.0)</value>
+    </param>
+    <param>
+      <key>seed</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>10.0**(-path_loss/20.0)</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_corr_est_cc</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(264, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_corr_est_cc_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>scale_factor</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>symbols</key>
+      <value>modulated_sync_word</value>
+    </param>
+    <param>
+      <key>mark_delay</key>
+      <value>mark_delay</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>0.999</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_pfb_clock_sync_xxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>filter_size</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(520, 203)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_pfb_clock_sync_xxx_0</value>
+    </param>
+    <param>
+      <key>init_phase</key>
+      <value>nfilts/2</value>
+    </param>
+    <param>
+      <key>loop_bw</key>
+      <value>6.28/400.0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max_dev</key>
+      <value>1.5</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>osps</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>rx_psf_taps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccf</value>
+    </param>
+  </block>
+  <block>
+    <key>interp_fir_filter_xxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(896, 99)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>interp_fir_filter_xxx_0</value>
+    </param>
+    <param>
+      <key>interp</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>samp_delay</key>
+      <value>filt_delay</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>rrc_taps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccc</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(832, 291)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>512</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(832, 211)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>corr_start</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>1.5</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-1.5</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(528, 363)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>512</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>corr_est</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-100</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(720, 435)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0_0_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>512</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>corr_est</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>4000</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-100</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(296, 435)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab0</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Corr</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>|Corr|^2</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Tab 2</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(296, 515)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>2,0,1,2</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab1</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Tab 2</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_add_const_vxx_0</source_block_id>
+    <sink_block_id>blocks_throttle_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_complex_to_mag_squared_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>blocks_add_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_stream_to_tagged_stream_0</source_block_id>
+    <sink_block_id>interp_fir_filter_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_throttle_0</source_block_id>
+    <sink_block_id>blocks_stream_to_tagged_stream_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_vector_source_x_0</source_block_id>
+    <sink_block_id>blocks_multiply_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>channels_channel_model_0</source_block_id>
+    <sink_block_id>digital_corr_est_cc_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_corr_est_cc_0</source_block_id>
+    <sink_block_id>blocks_complex_to_mag_squared_0</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_corr_est_cc_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0_0</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_corr_est_cc_0</source_block_id>
+    <sink_block_id>digital_pfb_clock_sync_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_pfb_clock_sync_xxx_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_pfb_clock_sync_xxx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>interp_fir_filter_xxx_0</source_block_id>
+    <sink_block_id>channels_channel_model_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/example_corr_est_and_phase_sync.grc 
b/gr-digital/examples/packet/example_corr_est_and_phase_sync.grc
new file mode 100644
index 0000000..1e9bbba
--- /dev/null
+++ b/gr-digital/examples/packet/example_corr_est_and_phase_sync.grc
@@ -0,0 +1,3474 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Tue Apr  5 13:57:36 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>example_corr_est_and_phase_sync</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(280, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>ac</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>map(lambda x: int(x), 
list(digital.packet_utils.default_access_code))</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 595)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>ac_hex</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[0xac, 0xdd, 0xa4, 0xe2, 0xf2, 0x8c, 0x20, 0xfc]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(584, 531)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.22</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(768, 531)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>filt_delay</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1+(len(rrc_taps)-1)/2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 563)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>freq_off</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Freq. Off.</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>-0.25</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.0001</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>0.25</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(960, 523)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_const</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(672, 531)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mark_delay</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>mark_delays[sps]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value>Tag Marking Delay for 
+Corr Est block, indexed
+by sps.
+
+Found empirically.</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 675)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mark_delays</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[0, 0, 34, 56, 87, 119]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_modulate_vector</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>data</key>
+      <value>ac_hex</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>[1]</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(960, 651)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>modulated_sync_word</value>
+    </param>
+    <param>
+      <key>mod</key>
+      <value>rxmod</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1104, 451)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>-50</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(176, 435)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>noise</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Noise Power</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>-50</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 435)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>path_loss</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Path Loss (dB)</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>5</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>140</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1120, 523)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rrc_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>11*sps</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(960, 387)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_psf_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>11*sps*nfilts</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>sps*nfilts</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(672, 595)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rxmod</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.generic_mod(hdr_const, False, sps, True, eb, False, 
False)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(184, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>10e3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(512, 531)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(176, 563)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>time_off</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Time Off.</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0.9999</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.00001</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>1.0001</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_add_const_vxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(368, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_add_const_vxx_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_complex_to_mag_squared</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(528, 457)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_complex_to_mag_squared_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_multiply_const_vxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_multiply_const_vxx_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_stream_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(664, 99)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_stream_to_tagged_stream_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>"packet_len"</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>packet_len</key>
+      <value>len(ac)+16</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_throttle</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_throttle_0</value>
+    </param>
+    <param>
+      <key>ignoretag</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_vector_source_x</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_vector_source_x_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tags</key>
+      <value>[]</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>vector</key>
+      <value>[1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0] + ac</value>
+    </param>
+  </block>
+  <block>
+    <key>channels_channel_model</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>block_tags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>epsilon</key>
+      <value>time_off</value>
+    </param>
+    <param>
+      <key>freq_offset</key>
+      <value>freq_off</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 203)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>channels_channel_model_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>noise_voltage</key>
+      <value>sps * 10.0**(noise/10.0)</value>
+    </param>
+    <param>
+      <key>seed</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>10.0**(-path_loss/20.0)</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_corr_est_cc</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(264, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_corr_est_cc_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>scale_factor</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>symbols</key>
+      <value>modulated_sync_word</value>
+    </param>
+    <param>
+      <key>mark_delay</key>
+      <value>mark_delay</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>0.999</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_costas_loop_cc</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(760, 209)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_costas_loop_cc_0_0</value>
+    </param>
+    <param>
+      <key>w</key>
+      <value>6.28/100.0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>order</key>
+      <value>hdr_const.arity()</value>
+    </param>
+    <param>
+      <key>use_snr</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_pfb_clock_sync_xxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>filter_size</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(520, 203)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_pfb_clock_sync_xxx_0</value>
+    </param>
+    <param>
+      <key>init_phase</key>
+      <value>nfilts/2</value>
+    </param>
+    <param>
+      <key>loop_bw</key>
+      <value>6.28/400.0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max_dev</key>
+      <value>1.5</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>osps</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>rx_psf_taps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccf</value>
+    </param>
+  </block>
+  <block>
+    <key>interp_fir_filter_xxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(896, 99)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>interp_fir_filter_xxx_0</value>
+    </param>
+    <param>
+      <key>interp</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>samp_delay</key>
+      <value>filt_delay</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>rrc_taps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccc</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1000, 291)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden: 0,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>512</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(760, 291)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden: 0,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>512</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1000, 211)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>corr_start</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>1.5</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-1.5</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(528, 363)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>512</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>corr_est</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-100</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(720, 435)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0_0_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>512</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>corr_est</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>4000</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-100</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(296, 435)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab0</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Corr</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>|Corr|^2</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Tab 2</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(296, 515)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>2,0,1,2</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab1</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Tab 2</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_add_const_vxx_0</source_block_id>
+    <sink_block_id>blocks_throttle_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_complex_to_mag_squared_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>blocks_add_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_stream_to_tagged_stream_0</source_block_id>
+    <sink_block_id>interp_fir_filter_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_throttle_0</source_block_id>
+    <sink_block_id>blocks_stream_to_tagged_stream_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_vector_source_x_0</source_block_id>
+    <sink_block_id>blocks_multiply_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>channels_channel_model_0</source_block_id>
+    <sink_block_id>digital_corr_est_cc_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_corr_est_cc_0</source_block_id>
+    <sink_block_id>blocks_complex_to_mag_squared_0</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_corr_est_cc_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0_0</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_corr_est_cc_0</source_block_id>
+    <sink_block_id>digital_pfb_clock_sync_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_costas_loop_cc_0_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_costas_loop_cc_0_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_pfb_clock_sync_xxx_0</source_block_id>
+    <sink_block_id>digital_costas_loop_cc_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_pfb_clock_sync_xxx_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>interp_fir_filter_xxx_0</source_block_id>
+    <sink_block_id>channels_channel_model_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/formatter_crc.grc 
b/gr-digital/examples/packet/formatter_crc.grc
new file mode 100644
index 0000000..f65d4d0
--- /dev/null
+++ b/gr-digital/examples/packet/formatter_crc.grc
@@ -0,0 +1,958 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Sun Apr 10 12:10:29 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 13)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>formatter_crc</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(168, 13)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.header_format_crc(len_key, num_key)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value>Need another for this path
+as the formatters keep state.</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(296, 477)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format_bb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.header_format_crc(len_key, num_key)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(352, 13)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>len_key</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"packet_len"</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(464, 13)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>num_key</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"packet_num"</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 225)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(760, 105)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(992, 425)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0_0_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 293)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.PMT_T</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>2000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(56, 132)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>len_key</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(64, 420)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>len_key</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0xff</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(200, 279)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(288, 125)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>len_key</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(544, 413)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>len_key</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tag_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>display</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(752, 502)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tag_debug_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>filter</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value></value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_crc32_async_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(424, 300)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_crc32_async_bb_1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>check</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_formatter_async</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(616, 289)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_formatter_async_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_formatter_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format_bb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(296, 413)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_formatter_bb_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>len_key</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_parser_b</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(496, 132)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_parser_b_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_parser_b</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format_bb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(752, 420)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_parser_b_0_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0_0</source_block_id>
+    <sink_block_id>digital_protocol_formatter_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>digital_crc32_async_bb_1</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0</source_block_id>
+    <sink_block_id>digital_protocol_parser_b_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0_0</source_block_id>
+    <sink_block_id>blocks_tag_debug_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0_0</source_block_id>
+    <sink_block_id>digital_protocol_parser_b_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>digital_protocol_formatter_async_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>header</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0</sink_block_id>
+    <source_key>header</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_bb_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_parser_b_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0_0</sink_block_id>
+    <source_key>info</source_key>
+    <sink_key>print</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_parser_b_0_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0_0_0</sink_block_id>
+    <source_key>info</source_key>
+    <sink_key>print</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/formatter_ofdm.grc 
b/gr-digital/examples/packet/formatter_ofdm.grc
new file mode 100644
index 0000000..cec6692
--- /dev/null
+++ b/gr-digital/examples/packet/formatter_ofdm.grc
@@ -0,0 +1,1157 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Sun Apr 10 12:10:29 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 13)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>formatter_ofdm</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(584, 13)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>frame_key</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"frame_len"</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(168, 13)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.header_format_ofdm(occupied_carriers, 1, len_key, 
frame_key, num_key, header_mod.bits_per_symbol(), 
payload_mod.bits_per_symbol(), scramble)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value>Need another for this path
+as the formatters keep state.</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(296, 477)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format_bb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.header_format_ofdm(occupied_carriers, 1, len_key, 
frame_key, num_key, header_mod.bits_per_symbol(), 
payload_mod.bits_per_symbol(), scramble)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation_rect</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>[1, -1]</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(944, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>header_mod</value>
+    </param>
+    <param>
+      <key>imag_sect</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>real_sect</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>None</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>[0, 1]</value>
+    </param>
+    <param>
+      <key>w_imag_sect</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>w_real_sect</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(352, 13)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>len_key</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"packet_len"</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(464, 13)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>num_key</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"packet_num"</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(784, 13)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>occupied_carriers</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>(range(-26, -21) + range(-20, -7) + range(-6, 0) + range(1, 7) + 
range(8, 21) + range(22, 27),)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation_rect</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>[-1-1j, -1+1j, 1+1j, 1-1j]</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1128, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>payload_mod</value>
+    </param>
+    <param>
+      <key>imag_sect</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>real_sect</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>None</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>[0, 1, 3, 2]</value>
+    </param>
+    <param>
+      <key>w_imag_sect</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>w_real_sect</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(696, 13)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>scramble</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 225)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(760, 105)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(992, 425)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0_0_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 293)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.PMT_T</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>2000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(56, 132)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>len_key</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(64, 420)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>len_key</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0xff</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(200, 279)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(288, 125)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>len_key</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(544, 413)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>len_key</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tag_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>display</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(752, 502)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tag_debug_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>filter</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value></value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_crc32_async_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(424, 300)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_crc32_async_bb_1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>check</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_formatter_async</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(616, 289)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_formatter_async_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_formatter_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format_bb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(296, 413)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_formatter_bb_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>len_key</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_parser_b</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(496, 132)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_parser_b_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_parser_b</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format_bb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(752, 420)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_parser_b_0_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0_0</source_block_id>
+    <sink_block_id>digital_protocol_formatter_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>digital_crc32_async_bb_1</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0</source_block_id>
+    <sink_block_id>digital_protocol_parser_b_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0_0</source_block_id>
+    <sink_block_id>blocks_tag_debug_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0_0</source_block_id>
+    <sink_block_id>digital_protocol_parser_b_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>digital_protocol_formatter_async_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>header</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0</sink_block_id>
+    <source_key>header</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_bb_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_parser_b_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0_0</sink_block_id>
+    <source_key>info</source_key>
+    <sink_key>print</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_parser_b_0_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0_0_0</sink_block_id>
+    <source_key>info</source_key>
+    <sink_key>print</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/packet_loopback_hier.grc 
b/gr-digital/examples/packet/packet_loopback_hier.grc
new file mode 100644
index 0000000..9af2d46
--- /dev/null
+++ b/gr-digital/examples/packet/packet_loopback_hier.grc
@@ -0,0 +1,4442 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Thu Dec  4 14:34:25 2014</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>2000,2000</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>packet_loopback_hier</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(240, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_4()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(560, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_4()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(400, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(72, 547)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>amp</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.01</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_cc_decoder_def</key>
+    <param>
+      <key>padding</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>k</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>state_end</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1152, 635)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>polys</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>rate</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>state_start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>mode</key>
+      <value>fec.CC_TERMINATED</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_decoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(760, 539)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_repetition_decoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 555)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>rep</key>
+      <value>rep</value>
+    </param>
+    <param>
+      <key>prob</key>
+      <value>0.5</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_decoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>hdr_format.header_nbits()</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1376, 539)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec_hdr</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_repetition_decoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>hdr_format.header_nbits()</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1560, 555)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec_hdr</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>rep</key>
+      <value>rep</value>
+    </param>
+    <param>
+      <key>prob</key>
+      <value>0.5</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(152, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.22</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_cc_encoder_def</key>
+    <param>
+      <key>padding</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>k</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1152, 459)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>polys</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>rate</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>state_start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>mode</key>
+      <value>fec.CC_TERMINATED</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(760, 459)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_repetition_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 459)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>rep</key>
+      <value>rep</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1376, 459)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc_hdr</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_repetition_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1560, 459)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc_hdr</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>rep</key>
+      <value>rep</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(984, 275)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>freq_offset</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Freq. Offset</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>-0.5</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.0001</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_header_format_default</key>
+    <param>
+      <key>access_code</key>
+      <value>digital.packet_utils.default_access_code</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(728, 14)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(728, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>value</key>
+      
<value>digital.header_format_counter(digital.packet_utils.default_access_code, 
3, Const_PLD.bits_per_symbol())</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1008, 675)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>7</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(80, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(872, 275)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>noise</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Noise Amp</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.01</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>5</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1056, 739)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[109, 79]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1080, 675)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(984, 739)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rep</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1080, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_rrc_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>11*sps*nfilts</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>nfilts*sps</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1096, 275)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,2,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>time_offset</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Time Offset</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0.99</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.00001</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>1.01</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(944, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_rrc_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>5*sps*nfilts</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(544, 321)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0_0_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(32, 195)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.intern("TEST")</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>1000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_multiply_const_vxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>amp</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(72, 499)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_multiply_const_vxx_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0xFF</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(240, 179)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>20</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1352, 155)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>chan_data</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Chan Data</value>
+    </param>
+  </block>
+  <block>
+    <key>channels_channel_model</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>block_tags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>epsilon</key>
+      <value>time_offset</value>
+    </param>
+    <param>
+      <key>freq_offset</key>
+      <value>freq_offset</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 147)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>channels_channel_model_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>noise_voltage</key>
+      <value>noise</value>
+    </param>
+    <param>
+      <key>seed</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>packet_rx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>eb</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(232, 409)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>hdr_dec</key>
+      <value>dec_hdr</value>
+    </param>
+    <param>
+      <key>hdr_format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>hdr_const</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>packet_rx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>pld_dec</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>pld_const</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>psf_taps</key>
+      <value>rx_rrc_taps</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+  </block>
+  <block>
+    <key>packet_tx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(496, 163)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>hdr_enc</key>
+      <value>enc_hdr</value>
+    </param>
+    <param>
+      <key>hdr_format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>hdr_const</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>packet_tx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>pld_enc</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>pld_const</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>psf_taps</key>
+      <value>tx_rrc_taps</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1352, 363)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(544, 419)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0_0_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>800</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_freq_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>bw</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>fc</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fftsize</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1352, 283)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_freq_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"dark blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>showports</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>freqhalf</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>wintype</key>
+      <value>firdes.WIN_BLACKMAN_hARRIS</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Relative Gain</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-140</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>dB</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_freq_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>bw</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>fc</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>fftsize</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(544, 483)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_freq_sink_x_0_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"dark blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>showports</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>freqhalf</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>wintype</key>
+      <value>firdes.WIN_BLACKMAN_hARRIS</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Relative Gain</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-140</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>dB</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1352, 203)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_1</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>2500</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(544, 643)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_1_0_0_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1250</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>"corr_est"</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Correlation</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>150</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-150</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(544, 563)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_1_0_0_1</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>3</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>125</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>25</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>"payload symbols"</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1360, 11)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab0</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Freq.</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1224, 11)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,2,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab1</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Freq.</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 427)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>virtual_source_0</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Chan Data</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>packet_rx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>packet_tx_0</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>channels_channel_model_0</source_block_id>
+    <sink_block_id>chan_data</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>channels_channel_model_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>channels_channel_model_0</source_block_id>
+    <sink_block_id>qtgui_freq_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>channels_channel_model_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_rx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_1_0_0_0</sink_block_id>
+    <source_key>4</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_rx_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0_0_0</sink_block_id>
+    <source_key>pkt out</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_rx_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0_0_0</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_rx_0</source_block_id>
+    <sink_block_id>qtgui_freq_sink_x_0_0</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_rx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_1_0_0_1</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_tx_0</source_block_id>
+    <sink_block_id>channels_channel_model_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>virtual_source_0</source_block_id>
+    <sink_block_id>blocks_multiply_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/packet_rx.grc 
b/gr-digital/examples/packet/packet_rx.grc
new file mode 100644
index 0000000..bce0b58
--- /dev/null
+++ b/gr-digital/examples/packet/packet_rx.grc
@@ -0,0 +1,1895 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Thu Mar 10 17:25:47 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Packet Operators</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>hb</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>packet_rx</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(32, 355)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mark_delay</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>mark_delays[sps]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value>Tag Marking Delay for 
+Corr Est block, indexed
+by sps.
+
+Found empirically.</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(32, 419)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mark_delays</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[0, 0, 34, 56, 87, 119]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_modulate_vector</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>data</key>
+      <value>preamble</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>[1]</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(744, 363)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>modulated_sync_word</value>
+    </param>
+    <param>
+      <key>mod</key>
+      <value>rxmod</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(728, 579)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>preamble</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>preamble_select[int(1.0/hdr_dec.rate())]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value>use when header
+FEC is Dummy</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(560, 467)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>preamble_dummy</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[0xac, 0xdd, 0xa4, 0xe2, 0xf2, 0x8c, 0x20, 0xfc]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value>use when header
+FEC is Repetition (x3)</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(728, 467)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>preamble_rep</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[0xe3, 0x8f, 0xc0, 0xfc, 0x7f, 0xc7, 0xe3, 0x81, 0xc0, 0xff, 
0x80, 0x38, 0xff, 0xf0, 0x38, 0xe0, 0x0f, 0xc0, 0x03, 0x80, 0x00, 0xff, 0xff, 
0xc0]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(560, 579)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>preamble_select</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>{1: preamble_dummy, 3: preamble_rep}</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(560, 395)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rxmod</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.generic_mod(hdr_const, False, sps, True, eb, False, 
False)</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_multiply_by_tag_value_cc</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(384, 227)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_multiply_by_tag_value_cc_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tagname</key>
+      <value>"amp_est"</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tagged_stream_multiply_length</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1600, 345)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tagged_stream_multiply_length_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>c</key>
+      <value>pld_const.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>lengthtagname</key>
+      <value>"payload symbols"</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tagged_stream_to_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1136, 451)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tagged_stream_to_pdu_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>"payload symbols"</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_constellation_soft_decoder_cf</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>constellation</key>
+      <value>pld_const</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1368, 339)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_constellation_soft_decoder_cf_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_constellation_soft_decoder_cf</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>constellation</key>
+      <value>hdr_const</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1368, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_constellation_soft_decoder_cf_0_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_corr_est_cc</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(144, 227)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_corr_est_cc_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>symbols</key>
+      <value>modulated_sync_word</value>
+    </param>
+    <param>
+      <key>mark_delay</key>
+      <value>mark_delay</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>0.999</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_costas_loop_cc</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1160, 225)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_costas_loop_cc_0_0</value>
+    </param>
+    <param>
+      <key>w</key>
+      <value>6.28/200.0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>order</key>
+      <value>hdr_const.arity()</value>
+    </param>
+    <param>
+      <key>use_snr</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_costas_loop_cc</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1144, 345)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_costas_loop_cc_0_0_0</value>
+    </param>
+    <param>
+      <key>w</key>
+      <value>6.28/200.0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>order</key>
+      <value>pld_const.arity()</value>
+    </param>
+    <param>
+      <key>use_snr</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_crc32_async_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1608, 451)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_crc32_async_bb_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>check</key>
+      <value>True</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_header_payload_demux</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(888, 227)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>guard_interval</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>header_len</key>
+      <value>(hdr_format.header_nbits() * int(1.0/hdr_dec.rate())) /  
hdr_const.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_header_payload_demux_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>items_per_symbol</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>length_tag_key</key>
+      <value>"payload symbols"</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>output_symbols</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>special_tags</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>timing_tag_key</key>
+      <value>"rx_time"</value>
+    </param>
+    <param>
+      <key>trigger_tag_key</key>
+      <value>"time_est"</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_pfb_clock_sync_xxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>filter_size</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(592, 187)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_pfb_clock_sync_xxx_0</value>
+    </param>
+    <param>
+      <key>init_phase</key>
+      <value>nfilts/2</value>
+    </param>
+    <param>
+      <key>loop_bw</key>
+      <value>6.28/400.0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max_dev</key>
+      <value>1.5</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>osps</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>psf_taps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccf</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_parser_b</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1024, 124)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_parser_b_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1408, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Filter Rolloff</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>eng_float</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.35</value>
+    </param>
+  </block>
+  <block>
+    <key>fec_async_decoder</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>decoder</key>
+      <value>pld_dec</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1368, 443)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>fec_async_decoder_0</value>
+    </param>
+    <param>
+      <key>mtu</key>
+      <value>1500*8</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>packed</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>rev_pack</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>fec_generic_decoder</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>decoder</key>
+      <value>hdr_dec</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1352, 124)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>fec_generic_decoder_0</value>
+    </param>
+    <param>
+      <key>itype</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>otype</key>
+      <value>byte</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(544, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_const</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Header constellation</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.constellation_calcdist((digital.psk_2()[0]), 
(digital.psk_2()[1]), 2, 1).base()</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(192, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_dec</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Header FEC Decoder</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value> fec.dummy_decoder.make(8000)</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(904, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Header Formatter</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      
<value>digital.header_format_default(digital.packet_utils.default_access_code, 
0)</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1768, 451)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_sink_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>message</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>pkt out</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1608, 499)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_sink_1</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>message</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>precrc</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(976, 179)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_sink_2</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>hdr_out</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(968, 372)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_sink_3</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>pld_out</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1368, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_sink_3_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>pld_phs</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(680, 139)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_sink_5</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>timing</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(224, 323)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_sink_7</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>corr est</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 251)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_source_0</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>in</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(720, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pld_const</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Payload constellation</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.constellation_calcdist((digital.psk_2()[0]), 
(digital.psk_2()[1]), 2, 1).base()</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(368, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pld_dec</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Payload FEC Decoder</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value> fec.dummy_decoder.make(8000)</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1256, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>psf_taps</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Pulse Shape Filter</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[0,]</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1096, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Samples per Symbol</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>eng_float</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_multiply_by_tag_value_cc_0</source_block_id>
+    <sink_block_id>digital_pfb_clock_sync_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_multiply_length_0</source_block_id>
+    <sink_block_id>blocks_tagged_stream_to_pdu_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_to_pdu_0</source_block_id>
+    <sink_block_id>fec_async_decoder_0</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_constellation_soft_decoder_cf_0</source_block_id>
+    <sink_block_id>blocks_tagged_stream_multiply_length_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    
<source_block_id>digital_constellation_soft_decoder_cf_0_0</source_block_id>
+    <sink_block_id>fec_generic_decoder_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_corr_est_cc_0</source_block_id>
+    <sink_block_id>pad_sink_7</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_corr_est_cc_0</source_block_id>
+    <sink_block_id>blocks_multiply_by_tag_value_cc_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_costas_loop_cc_0_0</source_block_id>
+    <sink_block_id>digital_constellation_soft_decoder_cf_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_costas_loop_cc_0_0_0</source_block_id>
+    <sink_block_id>digital_constellation_soft_decoder_cf_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_costas_loop_cc_0_0_0</source_block_id>
+    <sink_block_id>pad_sink_3_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_0</source_block_id>
+    <sink_block_id>pad_sink_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_header_payload_demux_0</source_block_id>
+    <sink_block_id>digital_costas_loop_cc_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_header_payload_demux_0</source_block_id>
+    <sink_block_id>pad_sink_2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_header_payload_demux_0</source_block_id>
+    <sink_block_id>digital_costas_loop_cc_0_0_0</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_header_payload_demux_0</source_block_id>
+    <sink_block_id>pad_sink_3</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_pfb_clock_sync_xxx_0</source_block_id>
+    <sink_block_id>digital_header_payload_demux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_pfb_clock_sync_xxx_0</source_block_id>
+    <sink_block_id>pad_sink_5</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_parser_b_0</source_block_id>
+    <sink_block_id>digital_header_payload_demux_0</sink_block_id>
+    <source_key>info</source_key>
+    <sink_key>header_data</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fec_async_decoder_0</source_block_id>
+    <sink_block_id>digital_crc32_async_bb_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fec_async_decoder_0</source_block_id>
+    <sink_block_id>pad_sink_1</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fec_generic_decoder_0</source_block_id>
+    <sink_block_id>digital_protocol_parser_b_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>pad_source_0</source_block_id>
+    <sink_block_id>digital_corr_est_cc_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/packet_tx.grc 
b/gr-digital/examples/packet/packet_tx.grc
new file mode 100644
index 0000000..66772ee
--- /dev/null
+++ b/gr-digital/examples/packet/packet_tx.grc
@@ -0,0 +1,1787 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Thu Mar 10 17:16:22 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Packet Operators</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>hb</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>packet_tx</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(784, 435)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>filt_delay</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1+(taps_per_filt-1)/2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1240, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(688, 435)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>taps_per_filt</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>len(psf_taps)/nfilts</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(536, 252)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(536, 179)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>hdr_const.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(760, 171)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>pld_const.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(760, 243)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tagged_stream_multiply_length</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 369)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tagged_stream_multiply_length_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>c</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>lengthtagname</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tagged_stream_mux</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 353)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tagged_stream_mux_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>lengthtagname</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ninputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>tag_preserve_head_pos</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_burst_shaper_xx</key>
+    <param>
+      <key>alias</key>
+      <value>burst_shaper0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(448, 331)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_burst_shaper_xx_0</value>
+    </param>
+    <param>
+      <key>insert_phasing</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>length_tag_name</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>post_padding</key>
+      <value>filt_delay</value>
+    </param>
+    <param>
+      <key>pre_padding</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>window</key>
+      <value>firdes.window(firdes.WIN_HANN, 20, 0)</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1088, 171)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>hdr_const.points()</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1088, 243)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0_0</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>pld_const.points()</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_crc32_async_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_crc32_async_bb_1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>check</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_map_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(960, 179)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_map_bb_1</value>
+    </param>
+    <param>
+      <key>map</key>
+      <value>hdr_const.pre_diff_code()</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_map_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(960, 251)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_map_bb_1_0</value>
+    </param>
+    <param>
+      <key>map</key>
+      <value>pld_const.pre_diff_code()</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_formatter_async</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(56, 225)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_formatter_async_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>fec_async_encoder</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>encoder</key>
+      <value>pld_enc</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(64, 99)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>fec_async_encoder_0</value>
+    </param>
+    <param>
+      <key>mtu</key>
+      <value>1500</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>packed</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>rev_pack</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>rev_unpack</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>fec_async_encoder</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>encoder</key>
+      <value>hdr_enc</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(304, 171)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>fec_async_encoder_0_0</value>
+    </param>
+    <param>
+      <key>mtu</key>
+      <value>1500</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>packed</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>rev_pack</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>rev_unpack</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(552, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_const</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Header constellation</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.constellation_calcdist((digital.psk_2()[0]), 
(digital.psk_2()[1]), 2, 1).base()</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(192, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_enc</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Header FEC encoder</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value> fec.dummy_encoder_make(8000)</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(904, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Header Formatter</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      
<value>digital.header_format_default(digital.packet_utils.default_access_code, 
0)</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1272, 179)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mod_header</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Header</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1272, 251)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mod_payload</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Payload</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1240, 379)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_sink_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>out</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(144, 163)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_sink_1</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>message</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>postcrc</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(368, 507)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_sink_2</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>mux</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 507)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_sink_3</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>burst</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>pad_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pad_source_0</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>in</value>
+    </param>
+    <param>
+      <key>num_streams</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>optional</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>message</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>pfb_arb_resampler_xxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(688, 339)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pfb_arb_resampler_xxx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>nfilts</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>rrate</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>samp_delay</key>
+      <value>filt_delay</value>
+    </param>
+    <param>
+      <key>atten</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>psf_taps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccf</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(728, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pld_const</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Payload constellation</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>digital.constellation_calcdist((digital.psk_2()[0]), 
(digital.psk_2()[1]), 2, 1).base()</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(368, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pld_enc</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Payload FEC encoder</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value> fec.dummy_encoder_make(8000)</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1240, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>psf_taps</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Pulse Shape Filter</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[0,]</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 331)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_mod_header</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Header</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 379)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_mod_payload</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Payload</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1080, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Samples per Symbol</value>
+    </param>
+    <param>
+      <key>short_id</key>
+      <value></value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>eng_float</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0</source_block_id>
+    <sink_block_id>digital_map_bb_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0_0</source_block_id>
+    <sink_block_id>digital_map_bb_1_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_multiply_length_0</source_block_id>
+    <sink_block_id>pad_sink_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_mux_0</source_block_id>
+    <sink_block_id>digital_burst_shaper_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_mux_0</source_block_id>
+    <sink_block_id>pad_sink_2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_burst_shaper_xx_0</source_block_id>
+    <sink_block_id>pad_sink_3</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_burst_shaper_xx_0</source_block_id>
+    <sink_block_id>pfb_arb_resampler_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0</source_block_id>
+    <sink_block_id>mod_header</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0_0</source_block_id>
+    <sink_block_id>mod_payload</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>fec_async_encoder_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>pad_sink_1</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_map_bb_1</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_map_bb_1_0</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>fec_async_encoder_0_0</sink_block_id>
+    <source_key>header</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0</sink_block_id>
+    <source_key>payload</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fec_async_encoder_0</source_block_id>
+    <sink_block_id>digital_protocol_formatter_async_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fec_async_encoder_0_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>pad_source_0</source_block_id>
+    <sink_block_id>digital_crc32_async_bb_1</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>pfb_arb_resampler_xxx_0</source_block_id>
+    <sink_block_id>blocks_tagged_stream_multiply_length_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>rx_mod_header</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>rx_mod_payload</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/simple_bpsk_tx.grc 
b/gr-digital/examples/packet/simple_bpsk_tx.grc
new file mode 100644
index 0000000..3a2dd3d
--- /dev/null
+++ b/gr-digital/examples/packet/simple_bpsk_tx.grc
@@ -0,0 +1,3071 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Thu Apr  7 13:34:29 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 8)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>simple_bpsk_tx</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.7</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(136, 547)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>amp</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.005</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>0.9</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(80, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.22</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>483e6-300</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(136, 419)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Frequency</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>50e6</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>500e3</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>3e9</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>56</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 547)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>gain</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Gain</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>83</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(496, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pkt_len</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1000</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(960, 531)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_rrc_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>15*sps</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>200e3</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 419)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Sample Rate</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>200e3</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>200e3</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>10e6</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(184, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_rrc_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>15*sps</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(440, 113)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 163)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.intern("TEST")</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>4000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_multiply_const_vxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>amp</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1344, 467)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_multiply_const_vxx_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(440, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0x0F</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(200, 147)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>6</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>6</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tag_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>display</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1600, 595)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tag_debug_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>filter</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value></value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tagged_stream_multiply_length</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(616, 321)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tagged_stream_multiply_length_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>c</key>
+      <value>sps*8</value>
+    </param>
+    <param>
+      <key>lengthtagname</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_unpack_k_bits_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 315)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_unpack_k_bits_bb_0</value>
+    </param>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 307)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>[-1,1]</value>
+    </param>
+  </block>
+  <block>
+    <key>fir_filter_xxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>decim</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 459)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>fir_filter_xxx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>samp_delay</key>
+      <value>1 + (len(rx_rrc_taps)-1)/2</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>rx_rrc_taps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccc</value>
+    </param>
+  </block>
+  <block>
+    <key>interp_fir_filter_xxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(408, 307)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>interp_fir_filter_xxx_0</value>
+    </param>
+    <param>
+      <key>interp</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>samp_delay</key>
+      <value>(len(tx_rrc_taps)-1)/(2*sps)</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>tx_rrc_taps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccc</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1600, 531)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_freq_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>bw</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>fc</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fftsize</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1600, 451)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_freq_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"dark blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>showports</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>freqhalf</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>wintype</key>
+      <value>firdes.WIN_BLACKMAN_hARRIS</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Relative Gain</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-140</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>dB</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1600, 371)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_1</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>600</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(336, 11)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>2,0,1,2</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab0</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Freq.</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>uhd_usrp_sink</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ant0</key>
+      <value>TX/RX</value>
+    </param>
+    <param>
+      <key>bw0</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq0</key>
+      <value>uhd.tune_request(freq, samp_rate/2.0)</value>
+    </param>
+    <param>
+      <key>norm_gain0</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain0</key>
+      <value>gain</value>
+    </param>
+    <param>
+      <key>ant10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain10</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant11</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain11</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant12</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain12</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant13</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain13</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant14</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain14</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant15</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain15</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant16</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain16</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant17</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain17</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant18</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain18</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant19</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain19</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain1</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant20</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain20</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant21</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain21</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant22</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain22</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant23</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain23</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant24</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain24</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant25</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain25</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant26</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain26</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant27</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain27</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant28</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain28</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant29</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain29</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain2</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant30</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain30</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant31</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain31</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain3</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain4</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain5</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain6</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain7</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain8</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain9</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>clock_rate</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dev_addr</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>dev_args</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1432, 139)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>uhd_usrp_sink_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>fc32</value>
+    </param>
+    <param>
+      <key>clock_source0</key>
+      <value>gpsdo</value>
+    </param>
+    <param>
+      <key>sd_spec0</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source0</key>
+      <value>gpsdo</value>
+    </param>
+    <param>
+      <key>clock_source1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>nchan</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_mboards</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>hide_cmd_port</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>stream_args</key>
+      <value></value>
+    </param>
+    <param>
+      <key>stream_chans</key>
+      <value>[]</value>
+    </param>
+    <param>
+      <key>sync</key>
+      <value>sync</value>
+    </param>
+    <param>
+      <key>len_tag_name</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>otw</key>
+      <value></value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>blocks_tag_debug_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_freq_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>uhd_usrp_sink_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0</source_block_id>
+    <sink_block_id>blocks_unpack_k_bits_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_multiply_length_0</source_block_id>
+    <sink_block_id>fir_filter_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_unpack_k_bits_bb_0</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0</source_block_id>
+    <sink_block_id>interp_fir_filter_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fir_filter_xxx_0</source_block_id>
+    <sink_block_id>blocks_multiply_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>interp_fir_filter_xxx_0</source_block_id>
+    <sink_block_id>blocks_tagged_stream_multiply_length_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/transmitter_sim_hier.grc 
b/gr-digital/examples/packet/transmitter_sim_hier.grc
new file mode 100644
index 0000000..1ec7ebe
--- /dev/null
+++ b/gr-digital/examples/packet/transmitter_sim_hier.grc
@@ -0,0 +1,2313 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Thu Dec  4 14:34:25 2014</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>2000,2000</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>parse_packet_header_soft</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(184, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(344, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_4()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_4()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_cc_decoder_def</key>
+    <param>
+      <key>padding</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>k</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>state_end</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(752, 619)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>polys</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>rate</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>state_start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>mode</key>
+      <value>fec.CC_TERMINATED</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_decoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(360, 523)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_repetition_decoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(552, 539)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>rep</key>
+      <value>rep</value>
+    </param>
+    <param>
+      <key>prob</key>
+      <value>0.5</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(824, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.22</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_cc_encoder_def</key>
+    <param>
+      <key>padding</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>k</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(752, 443)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>polys</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>rate</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>state_start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>mode</key>
+      <value>fec.CC_TERMINATED</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(360, 443)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_repetition_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(552, 443)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>rep</key>
+      <value>rep</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(176, 443)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc_hdr</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_header_format_default</key>
+    <param>
+      <key>access_code</key>
+      <value>digital.packet_utils.default_access_code</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(720, 14)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(608, 659)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>7</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(752, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(656, 723)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[109, 79]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(680, 659)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(584, 723)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rep</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(768, 243)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_rrc_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>15*sps</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(680, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(912, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_rrc_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>5*sps*nfilts</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>sps*nfilts</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(592, 329)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(56, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.intern("TEST")</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>1000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0x0F</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(264, 195)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>fir_filter_xxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>decim</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(768, 171)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>fir_filter_xxx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>samp_delay</key>
+      <value>(len(rx_rrc_taps)-1)/2</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>rx_rrc_taps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccc</value>
+    </param>
+  </block>
+  <block>
+    <key>packet_tx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(520, 179)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>hdr_enc</key>
+      <value>enc_hdr</value>
+    </param>
+    <param>
+      <key>hdr_format</key>
+      
<value>digital.header_format_default(digital.packet_utils.default_access_code, 
0)</value>
+    </param>
+    <param>
+      <key>hdr_const</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>packet_tx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>pld_enc</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>pld_const</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>psf_taps</key>
+      <value>tx_rrc_taps</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1024, 323)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_freq_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>bw</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>fc</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fftsize</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1024, 243)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_freq_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"dark blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>showports</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>freqhalf</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>wintype</key>
+      <value>firdes.WIN_BLACKMAN_hARRIS</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Relative Gain</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-140</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>dB</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1024, 163)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>2,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_1</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1500</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(32, 443)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>2,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab0</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Const</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Freq</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Tab 2</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>packet_tx_0</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fir_filter_xxx_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fir_filter_xxx_0</source_block_id>
+    <sink_block_id>qtgui_freq_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fir_filter_xxx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_tx_0</source_block_id>
+    <sink_block_id>fir_filter_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_tx_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>postcrc</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/tx_stage0.grc 
b/gr-digital/examples/packet/tx_stage0.grc
new file mode 100644
index 0000000..e05f239
--- /dev/null
+++ b/gr-digital/examples/packet/tx_stage0.grc
@@ -0,0 +1,286 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Sun Apr 10 12:10:29 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_stage0</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(536, 97)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(32, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.PMT_T</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>2000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0xff</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>150</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tuntap_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>istunflag</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(224, 203)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tuntap_pdu_0</value>
+    </param>
+    <param>
+      <key>ifn</key>
+      <value>tap0</value>
+    </param>
+    <param>
+      <key>mtu</key>
+      <value>10000</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tuntap_pdu_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/tx_stage1.grc 
b/gr-digital/examples/packet/tx_stage1.grc
new file mode 100644
index 0000000..d897a05
--- /dev/null
+++ b/gr-digital/examples/packet/tx_stage1.grc
@@ -0,0 +1,284 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Sun Apr 10 12:10:29 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_stage1</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(672, 49)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(32, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.PMT_T</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>2000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0xff</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_crc32_async_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(456, 171)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_crc32_async_bb_1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>check</key>
+      <value>False</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>digital_crc32_async_bb_1</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/tx_stage2.grc 
b/gr-digital/examples/packet/tx_stage2.grc
new file mode 100644
index 0000000..a2b5386
--- /dev/null
+++ b/gr-digital/examples/packet/tx_stage2.grc
@@ -0,0 +1,494 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Sun Apr 10 12:10:29 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_stage2</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable_cc_encoder_def</key>
+    <param>
+      <key>padding</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>k</key>
+      <value>7</value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>1500*8</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>polys</key>
+      <value>[109,79]</value>
+    </param>
+    <param>
+      <key>rate</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>state_start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>mode</key>
+      <value>fec.CC_TERMINATED</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_repetition_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>rep</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(920, 57)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(32, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.PMT_T</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>2000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0xff</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_crc32_async_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(432, 115)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_crc32_async_bb_1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>check</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>fec_async_encoder</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>encoder</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(624, 171)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>fec_async_encoder_0</value>
+    </param>
+    <param>
+      <key>mtu</key>
+      <value>1500</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>packed</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>rev_pack</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>rev_unpack</key>
+      <value>False</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>digital_crc32_async_bb_1</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>fec_async_encoder_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fec_async_encoder_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/tx_stage3.grc 
b/gr-digital/examples/packet/tx_stage3.grc
new file mode 100644
index 0000000..1e83fdc
--- /dev/null
+++ b/gr-digital/examples/packet/tx_stage3.grc
@@ -0,0 +1,445 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Sun Apr 10 12:10:29 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_stage3</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(256, 285)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>bps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_header_format_default</key>
+    <param>
+      <key>access_code</key>
+      <value>digital.packet_utils.default_access_code</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 206)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>thresh</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(256, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>value</key>
+      
<value>digital.header_format_counter(digital.packet_utils.default_access_code, 
thresh, bps)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 285)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>thresh</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(920, 57)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(32, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.PMT_T</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>2000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0xff</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 91)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_crc32_async_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(432, 115)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_crc32_async_bb_1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>check</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_formatter_async</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(616, 105)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_formatter_async_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>digital_crc32_async_bb_1</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>digital_protocol_formatter_async_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>header</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>payload</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/tx_stage4.grc 
b/gr-digital/examples/packet/tx_stage4.grc
new file mode 100644
index 0000000..7acfd73
--- /dev/null
+++ b/gr-digital/examples/packet/tx_stage4.grc
@@ -0,0 +1,1948 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Sun Apr 10 12:10:29 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_stage4</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(272, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>bps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>pld_const.bits_per_symbol()</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(816, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_const</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_header_format_default</key>
+    <param>
+      <key>access_code</key>
+      <value>digital.packet_utils.default_access_code</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(400, 6)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>thresh</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(592, 5)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>value</key>
+      
<value>digital.header_format_counter(digital.packet_utils.default_access_code, 
thresh, bps)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(976, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pld_const</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(192, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>thresh</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 99)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.PMT_T</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>1000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0xff</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(208, 83)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>hdr_const.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(536, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>pld_const.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(536, 283)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tagged_stream_mux</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(224, 401)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tagged_stream_mux_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>lengthtagname</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ninputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>tag_preserve_head_pos</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(864, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>hdr_const.points()</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(864, 283)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0_0</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>pld_const.points()</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_crc32_async_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(424, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_crc32_async_bb_1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>check</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_map_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(736, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_map_bb_1</value>
+    </param>
+    <param>
+      <key>map</key>
+      <value>hdr_const.pre_diff_code()</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_map_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(736, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_map_bb_1_0</value>
+    </param>
+    <param>
+      <key>map</key>
+      <value>pld_const.pre_diff_code()</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_formatter_async</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(56, 233)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_formatter_async_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1048, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mod_header</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Header</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1048, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mod_payload</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Payload</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_freq_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>bw</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>fc</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fftsize</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1056, 443)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_freq_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"dark blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>showports</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>freqhalf</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>wintype</key>
+      <value>firdes.WIN_BLACKMAN_hARRIS</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Relative Gain</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-140</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>dB</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1056, 363)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>400</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 379)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_mod_header</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Header</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 427)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_mod_payload</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Payload</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1056, 531)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Freq</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Tab 2</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>digital_crc32_async_bb_1</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0</source_block_id>
+    <sink_block_id>digital_map_bb_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0_0</source_block_id>
+    <sink_block_id>digital_map_bb_1_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_mux_0</source_block_id>
+    <sink_block_id>qtgui_freq_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_mux_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0</source_block_id>
+    <sink_block_id>mod_header</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0_0</source_block_id>
+    <sink_block_id>mod_payload</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>digital_protocol_formatter_async_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_map_bb_1</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_map_bb_1_0</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0_0</sink_block_id>
+    <source_key>header</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0</sink_block_id>
+    <source_key>payload</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>rx_mod_header</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>rx_mod_payload</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/tx_stage5.grc 
b/gr-digital/examples/packet/tx_stage5.grc
new file mode 100644
index 0000000..b6a46eb
--- /dev/null
+++ b/gr-digital/examples/packet/tx_stage5.grc
@@ -0,0 +1,2017 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Sun Apr 10 12:10:29 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_stage5</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(272, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>bps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>pld_const.bits_per_symbol()</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(816, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_const</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_header_format_default</key>
+    <param>
+      <key>access_code</key>
+      <value>digital.packet_utils.default_access_code</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(400, 6)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>thresh</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(592, 5)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>value</key>
+      
<value>digital.header_format_counter(digital.packet_utils.default_access_code, 
thresh, bps)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(976, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pld_const</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(192, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>thresh</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 99)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.PMT_T</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>1000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0xff</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(208, 83)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>hdr_const.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(536, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>pld_const.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(536, 283)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tagged_stream_mux</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(224, 401)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tagged_stream_mux_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>lengthtagname</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ninputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>tag_preserve_head_pos</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_burst_shaper_xx</key>
+    <param>
+      <key>alias</key>
+      <value>burst_shaper0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(456, 379)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_burst_shaper_xx_0</value>
+    </param>
+    <param>
+      <key>insert_phasing</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>length_tag_name</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>post_padding</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>pre_padding</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>window</key>
+      <value>firdes.window(firdes.WIN_HANN, 50, 0)</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(864, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>hdr_const.points()</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(864, 283)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0_0</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>pld_const.points()</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_crc32_async_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(424, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_crc32_async_bb_1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>check</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_map_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(736, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_map_bb_1</value>
+    </param>
+    <param>
+      <key>map</key>
+      <value>hdr_const.pre_diff_code()</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_map_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(736, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_map_bb_1_0</value>
+    </param>
+    <param>
+      <key>map</key>
+      <value>pld_const.pre_diff_code()</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_formatter_async</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(56, 233)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_formatter_async_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1048, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mod_header</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Header</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1048, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mod_payload</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Payload</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_freq_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>bw</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>fc</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fftsize</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1056, 443)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_freq_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"dark blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>showports</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>freqhalf</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>wintype</key>
+      <value>firdes.WIN_BLACKMAN_hARRIS</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Relative Gain</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-140</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>dB</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1056, 363)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>400</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 379)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_mod_header</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Header</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 427)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_mod_payload</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Payload</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1056, 531)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Freq</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Tab 2</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>digital_crc32_async_bb_1</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0</source_block_id>
+    <sink_block_id>digital_map_bb_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0_0</source_block_id>
+    <sink_block_id>digital_map_bb_1_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_mux_0</source_block_id>
+    <sink_block_id>digital_burst_shaper_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_burst_shaper_xx_0</source_block_id>
+    <sink_block_id>qtgui_freq_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_burst_shaper_xx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0</source_block_id>
+    <sink_block_id>mod_header</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0_0</source_block_id>
+    <sink_block_id>mod_payload</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>digital_protocol_formatter_async_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_map_bb_1</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_map_bb_1_0</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0_0</sink_block_id>
+    <source_key>header</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0</sink_block_id>
+    <source_key>payload</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>rx_mod_header</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>rx_mod_payload</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/tx_stage6.grc 
b/gr-digital/examples/packet/tx_stage6.grc
new file mode 100644
index 0000000..4e2806f
--- /dev/null
+++ b/gr-digital/examples/packet/tx_stage6.grc
@@ -0,0 +1,2264 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Sun Apr 10 12:10:29 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_stage6</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(272, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>bps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>pld_const.bits_per_symbol()</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(936, 563)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.22</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(888, 499)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>filt_delay</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1+(taps_per_filt-1)/2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(816, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_const</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_header_format_default</key>
+    <param>
+      <key>access_code</key>
+      <value>digital.packet_utils.default_access_code</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(400, 6)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>thresh</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(592, 5)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>value</key>
+      
<value>digital.header_format_counter(digital.packet_utils.default_access_code, 
thresh, bps)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(864, 563)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(976, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pld_const</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(656, 499)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>psf_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>15*sps*nfilts</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(792, 563)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>4</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(792, 499)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>taps_per_filt</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>len(psf_taps)/nfilts</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(192, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>thresh</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 99)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.PMT_T</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>1000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0xff</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(208, 83)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>hdr_const.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(536, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>pld_const.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(536, 283)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tagged_stream_mux</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(224, 401)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tagged_stream_mux_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>lengthtagname</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ninputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>tag_preserve_head_pos</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_burst_shaper_xx</key>
+    <param>
+      <key>alias</key>
+      <value>burst_shaper0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(456, 379)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_burst_shaper_xx_0</value>
+    </param>
+    <param>
+      <key>insert_phasing</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>length_tag_name</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>post_padding</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>pre_padding</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>window</key>
+      <value>firdes.window(firdes.WIN_HANN, 50, 0)</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(864, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>hdr_const.points()</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(864, 283)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0_0</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>pld_const.points()</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_crc32_async_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(424, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_crc32_async_bb_1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>check</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_map_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(736, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_map_bb_1</value>
+    </param>
+    <param>
+      <key>map</key>
+      <value>hdr_const.pre_diff_code()</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_map_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(736, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_map_bb_1_0</value>
+    </param>
+    <param>
+      <key>map</key>
+      <value>pld_const.pre_diff_code()</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_formatter_async</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(56, 225)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_formatter_async_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1048, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mod_header</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Header</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1048, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mod_payload</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Payload</value>
+    </param>
+  </block>
+  <block>
+    <key>pfb_arb_resampler_xxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(720, 387)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pfb_arb_resampler_xxx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>nfilts</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>rrate</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>samp_delay</key>
+      <value>filt_delay</value>
+    </param>
+    <param>
+      <key>atten</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>psf_taps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccf</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_freq_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>bw</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>fc</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fftsize</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1056, 443)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_freq_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"dark blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>showports</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>freqhalf</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>wintype</key>
+      <value>firdes.WIN_BLACKMAN_hARRIS</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Relative Gain</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-140</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>dB</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1056, 363)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>400*sps</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 379)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_mod_header</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Header</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 427)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_mod_payload</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Payload</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1056, 531)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Freq</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Tab 2</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>digital_crc32_async_bb_1</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0</source_block_id>
+    <sink_block_id>digital_map_bb_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0_0</source_block_id>
+    <sink_block_id>digital_map_bb_1_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_mux_0</source_block_id>
+    <sink_block_id>digital_burst_shaper_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_burst_shaper_xx_0</source_block_id>
+    <sink_block_id>pfb_arb_resampler_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0</source_block_id>
+    <sink_block_id>mod_header</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0_0</source_block_id>
+    <sink_block_id>mod_payload</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>digital_protocol_formatter_async_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_map_bb_1</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_map_bb_1_0</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0_0</sink_block_id>
+    <source_key>header</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0</sink_block_id>
+    <source_key>payload</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>pfb_arb_resampler_xxx_0</source_block_id>
+    <sink_block_id>qtgui_freq_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>pfb_arb_resampler_xxx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>rx_mod_header</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>rx_mod_payload</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/tx_stage6a.grc 
b/gr-digital/examples/packet/tx_stage6a.grc
new file mode 100644
index 0000000..7c5565c
--- /dev/null
+++ b/gr-digital/examples/packet/tx_stage6a.grc
@@ -0,0 +1,2368 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Sun Apr 10 12:10:29 2016</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value></value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_stage6a</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(272, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>bps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>pld_const.bits_per_symbol()</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(936, 563)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.22</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(888, 499)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>filt_delay</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1+(taps_per_filt-1)/2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(816, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_const</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_header_format_default</key>
+    <param>
+      <key>access_code</key>
+      <value>digital.packet_utils.default_access_code</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(400, 6)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>thresh</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(592, 5)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>value</key>
+      
<value>digital.header_format_counter(digital.packet_utils.default_access_code, 
thresh, bps)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(864, 563)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(976, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pld_const</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(656, 499)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>psf_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>15*sps*nfilts</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1056, 467)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_psf_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>15*sps</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(792, 563)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>4</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(792, 499)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>taps_per_filt</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>len(psf_taps)/nfilts</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(192, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>thresh</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 99)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.PMT_T</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>1000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_pdu_to_tagged_stream</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_pdu_to_tagged_stream_0_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0xff</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(208, 83)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>hdr_const.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(536, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_repack_bits_bb</key>
+    <param>
+      <key>k</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>l</key>
+      <value>pld_const.bits_per_symbol()</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(536, 283)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_repack_bits_bb_0_0</value>
+    </param>
+    <param>
+      <key>len_tag_key</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>align_output</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tagged_stream_mux</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(224, 401)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tagged_stream_mux_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>lengthtagname</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ninputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>tag_preserve_head_pos</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_burst_shaper_xx</key>
+    <param>
+      <key>alias</key>
+      <value>burst_shaper0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(456, 379)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_burst_shaper_xx_0</value>
+    </param>
+    <param>
+      <key>insert_phasing</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>length_tag_name</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>post_padding</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>pre_padding</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>window</key>
+      <value>firdes.window(firdes.WIN_HANN, 50, 0)</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(864, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>hdr_const.points()</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_chunks_to_symbols_xx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(864, 283)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_chunks_to_symbols_xx_0_0</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>num_ports</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>pld_const.points()</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_crc32_async_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(424, 107)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_crc32_async_bb_1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>check</key>
+      <value>False</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_map_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(736, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_map_bb_1</value>
+    </param>
+    <param>
+      <key>map</key>
+      <value>hdr_const.pre_diff_code()</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_map_bb</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(736, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_map_bb_1_0</value>
+    </param>
+    <param>
+      <key>map</key>
+      <value>pld_const.pre_diff_code()</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_protocol_formatter_async</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(56, 225)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_protocol_formatter_async_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>fir_filter_xxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>decim</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1056, 403)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>fir_filter_xxx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>samp_delay</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>rx_psf_taps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccc</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1048, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mod_header</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Header</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_sink</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1048, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>mod_payload</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Payload</value>
+    </param>
+  </block>
+  <block>
+    <key>pfb_arb_resampler_xxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(720, 387)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>pfb_arb_resampler_xxx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>nfilts</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>rrate</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>samp_delay</key>
+      <value>filt_delay</value>
+    </param>
+    <param>
+      <key>atten</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>psf_taps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccf</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_freq_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>bw</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>fc</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>fftsize</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1320, 443)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_freq_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"dark blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>showports</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>freqhalf</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>wintype</key>
+      <value>firdes.WIN_BLACKMAN_hARRIS</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Relative Gain</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-140</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>dB</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1320, 363)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>400*sps</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 379)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_mod_header</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Header</value>
+    </param>
+  </block>
+  <block>
+    <key>virtual_source</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 427)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_mod_payload</value>
+    </param>
+    <param>
+      <key>stream_id</key>
+      <value>Mod Payload</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1320, 531)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Freq</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Const</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_pdu_to_tagged_stream_0_0</source_block_id>
+    <sink_block_id>blocks_repack_bits_bb_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>digital_crc32_async_bb_1</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0</source_block_id>
+    <sink_block_id>digital_map_bb_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_repack_bits_bb_0_0</source_block_id>
+    <sink_block_id>digital_map_bb_1_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tagged_stream_mux_0</source_block_id>
+    <sink_block_id>digital_burst_shaper_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_burst_shaper_xx_0</source_block_id>
+    <sink_block_id>pfb_arb_resampler_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0</source_block_id>
+    <sink_block_id>mod_header</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_chunks_to_symbols_xx_0_0</source_block_id>
+    <sink_block_id>mod_payload</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_crc32_async_bb_1</source_block_id>
+    <sink_block_id>digital_protocol_formatter_async_0</sink_block_id>
+    <source_key>out</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_map_bb_1</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_map_bb_1_0</source_block_id>
+    <sink_block_id>digital_chunks_to_symbols_xx_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0_0</sink_block_id>
+    <source_key>header</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_protocol_formatter_async_0</source_block_id>
+    <sink_block_id>blocks_pdu_to_tagged_stream_0</sink_block_id>
+    <source_key>payload</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fir_filter_xxx_0</source_block_id>
+    <sink_block_id>qtgui_freq_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fir_filter_xxx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>pfb_arb_resampler_xxx_0</source_block_id>
+    <sink_block_id>fir_filter_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>rx_mod_header</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>rx_mod_payload</source_block_id>
+    <sink_block_id>blocks_tagged_stream_mux_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/uhd_packet_rx.grc 
b/gr-digital/examples/packet/uhd_packet_rx.grc
new file mode 100644
index 0000000..8d902a5
--- /dev/null
+++ b/gr-digital/examples/packet/uhd_packet_rx.grc
@@ -0,0 +1,4083 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Thu Dec  4 14:34:25 2014</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>2000,2000</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>uhd_packet_rx</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(240, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_4()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(560, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_4()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(400, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>500</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(176, 595)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>amp</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>15000</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_cc_decoder_def</key>
+    <param>
+      <key>padding</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>k</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>state_end</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(680, 555)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>polys</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>rate</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>state_start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>mode</key>
+      <value>fec.CC_TERMINATED</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_decoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(496, 555)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_repetition_decoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(480, 635)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>rep</key>
+      <value>rep</value>
+    </param>
+    <param>
+      <key>prob</key>
+      <value>0.5</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_decoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(592, 475)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec_hdr</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(152, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.22</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>484e6</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(176, 467)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Frequency</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>480e6</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>490e6</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>20</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 595)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>gain</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Gain</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>31.5</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_header_format_default</key>
+    <param>
+      <key>access_code</key>
+      <value>digital.packet_utils.default_access_code</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(760, 14)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(760, 85)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>value</key>
+      
<value>digital.header_format_counter(digital.packet_utils.default_access_code, 
3, Const_PLD.bits_per_symbol())</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(904, 619)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>7</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(80, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_check_box</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>false</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 635)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>on</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>On</value>
+    </param>
+    <param>
+      <key>true</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>int</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 683)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[109, 79]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(976, 619)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(880, 683)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rep</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_rrc_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>11*sps*nfilts</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>sps*nfilts</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1000e3</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 467)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Sample Rate</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>200e3</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>200e3</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>10e6</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(968, 153)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0_0_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_multiply_const_vxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>amp</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(320, 163)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_multiply_const_vxx_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_multiply_const_vxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value>User gatting of on/off.
+Use the "On" check box
+to start sending samples
+to the receiver.</value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>on</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(528, 307)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_multiply_const_vxx_1</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_fll_band_edge_cc</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>rolloff</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(320, 313)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_fll_band_edge_cc_0</value>
+    </param>
+    <param>
+      <key>w</key>
+      <value>0.05</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>filter_size</key>
+      <value>44</value>
+    </param>
+    <param>
+      <key>samps_per_sym</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>cc</value>
+    </param>
+  </block>
+  <block>
+    <key>packet_rx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>eb</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(696, 201)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>hdr_dec</key>
+      <value>dec_hdr</value>
+    </param>
+    <param>
+      <key>hdr_format</key>
+      
<value>digital.header_format_default(digital.packet_utils.default_access_code, 
0)</value>
+    </param>
+    <param>
+      <key>hdr_const</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>packet_rx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>pld_dec</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>pld_const</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>psf_taps</key>
+      <value>rx_rrc_taps</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 147)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_NORM</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.01</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(992, 267)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0_0_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>800</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 211)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>0.5e-3</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_NORM</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.01</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(992, 331)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_1_0_0_1</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>3</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1250</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>25</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>"time_est"</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 467)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>2,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab0</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 547)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>2,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab1</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Const</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>uhd_usrp_source</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ant0</key>
+      <value>TX/RX</value>
+    </param>
+    <param>
+      <key>bw0</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq0</key>
+      <value>uhd.tune_request(freq, samp_rate/2.0)</value>
+    </param>
+    <param>
+      <key>dc_offs_enb0</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb0</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain0</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain0</key>
+      <value>gain</value>
+    </param>
+    <param>
+      <key>ant10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb10</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb10</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain10</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant11</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb11</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb11</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain11</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant12</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb12</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb12</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain12</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant13</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb13</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb13</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain13</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant14</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb14</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb14</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain14</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant15</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb15</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb15</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain15</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant16</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb16</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb16</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain16</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant17</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb17</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb17</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain17</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant18</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb18</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb18</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain18</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant19</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb19</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb19</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain19</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb1</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb1</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain1</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant20</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb20</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb20</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain20</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant21</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb21</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb21</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain21</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant22</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb22</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb22</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain22</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant23</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb23</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb23</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain23</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant24</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb24</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb24</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain24</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant25</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb25</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb25</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain25</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant26</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb26</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb26</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain26</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant27</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb27</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb27</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain27</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant28</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb28</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb28</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain28</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant29</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb29</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb29</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain29</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb2</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb2</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain2</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant30</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb30</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb30</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain30</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant31</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb31</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb31</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain31</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb3</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb3</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain3</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb4</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb4</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain4</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb5</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb5</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain5</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb6</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb6</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain6</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb7</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb7</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain7</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb8</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb8</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain8</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb9</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb9</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain9</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>clock_rate</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dev_addr</key>
+      <value>addr=192.168.10.2</value>
+    </param>
+    <param>
+      <key>dev_args</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 171)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>uhd_usrp_source_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>clock_source0</key>
+      <value>gpsdo</value>
+    </param>
+    <param>
+      <key>sd_spec0</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source0</key>
+      <value>gpsdo</value>
+    </param>
+    <param>
+      <key>clock_source1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>nchan</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_mboards</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>fc32</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>hide_cmd_port</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>stream_args</key>
+      <value></value>
+    </param>
+    <param>
+      <key>stream_chans</key>
+      <value>[]</value>
+    </param>
+    <param>
+      <key>sync</key>
+      <value></value>
+    </param>
+    <param>
+      <key>otw</key>
+      <value></value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_1</source_block_id>
+    <sink_block_id>packet_rx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_fll_band_edge_cc_0</source_block_id>
+    <sink_block_id>blocks_multiply_const_vxx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_rx_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0_0_0</sink_block_id>
+    <source_key>pkt out</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_rx_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0_0_0</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_rx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_1_0_0_1</sink_block_id>
+    <source_key>2</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>uhd_usrp_source_0</source_block_id>
+    <sink_block_id>blocks_multiply_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>uhd_usrp_source_0</source_block_id>
+    <sink_block_id>digital_fll_band_edge_cc_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/uhd_packet_rx_tun.grc 
b/gr-digital/examples/packet/uhd_packet_rx_tun.grc
new file mode 100644
index 0000000..c64cd95
--- /dev/null
+++ b/gr-digital/examples/packet/uhd_packet_rx_tun.grc
@@ -0,0 +1,4143 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Thu Dec  4 14:34:25 2014</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>2000,2000</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>uhd_packet_rx_tun</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(240, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_4()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(560, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_4()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(400, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>500</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(176, 595)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>amp</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>15000</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_cc_decoder_def</key>
+    <param>
+      <key>padding</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>k</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>state_end</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(680, 555)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>polys</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>rate</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>state_start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>mode</key>
+      <value>fec.CC_TERMINATED</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_decoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(496, 555)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_repetition_decoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(480, 635)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>rep</key>
+      <value>rep</value>
+    </param>
+    <param>
+      <key>prob</key>
+      <value>0.5</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_decoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(592, 475)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>dec_hdr</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"ok"</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(152, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.22</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>484e6</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(176, 467)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Frequency</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>400e6</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>500e6</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>20</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 595)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>gain</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Gain</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>31.5</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_header_format_default</key>
+    <param>
+      <key>access_code</key>
+      <value>digital.packet_utils.default_access_code</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(760, 14)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(760, 85)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>value</key>
+      
<value>digital.header_format_counter(digital.packet_utils.default_access_code, 
3, Const_PLD.bits_per_symbol())</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(904, 619)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>7</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(80, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_check_box</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>false</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 635)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>on</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>On</value>
+    </param>
+    <param>
+      <key>true</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>int</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 683)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[109, 79]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(976, 619)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(880, 683)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rep</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rx_rrc_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>11*sps*nfilts</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>sps*nfilts</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1000e3</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 467)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Sample Rate</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>200e3</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>200e3</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>10e6</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1120, 73)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_multiply_const_vxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>amp</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(320, 163)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_multiply_const_vxx_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_multiply_const_vxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>on</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(528, 307)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_multiply_const_vxx_1</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tuntap_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>istunflag</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(992, 179)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tuntap_pdu_0</value>
+    </param>
+    <param>
+      <key>ifn</key>
+      <value>tun0</value>
+    </param>
+    <param>
+      <key>mtu</key>
+      <value>10000</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>digital_fll_band_edge_cc</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>rolloff</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(320, 313)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>digital_fll_band_edge_cc_0</value>
+    </param>
+    <param>
+      <key>w</key>
+      <value>0.05</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>filter_size</key>
+      <value>44</value>
+    </param>
+    <param>
+      <key>samps_per_sym</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>cc</value>
+    </param>
+  </block>
+  <block>
+    <key>packet_rx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>eb</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(696, 201)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>hdr_dec</key>
+      <value>dec_hdr</value>
+    </param>
+    <param>
+      <key>hdr_format</key>
+      
<value>digital.header_format_default(digital.packet_utils.default_access_code, 
0)</value>
+    </param>
+    <param>
+      <key>hdr_const</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>packet_rx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>pld_dec</key>
+      <value>dec</value>
+    </param>
+    <param>
+      <key>pld_const</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>psf_taps</key>
+      <value>rx_rrc_taps</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 147)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_NORM</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.01</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(992, 267)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0_0_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>800</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(504, 211)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>0.5e-3</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_NORM</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.01</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(992, 331)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_1_0_0_1</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>3</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1250</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>25</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_TAG</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>"time_est"</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 467)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>2,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab0</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(312, 547)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>2,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab1</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Const</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>uhd_usrp_source</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ant0</key>
+      <value>TX/RX</value>
+    </param>
+    <param>
+      <key>bw0</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq0</key>
+      <value>uhd.tune_request(freq, samp_rate/2.0)</value>
+    </param>
+    <param>
+      <key>dc_offs_enb0</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb0</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain0</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain0</key>
+      <value>gain</value>
+    </param>
+    <param>
+      <key>ant10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb10</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb10</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain10</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant11</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb11</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb11</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain11</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant12</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb12</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb12</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain12</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant13</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb13</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb13</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain13</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant14</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb14</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb14</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain14</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant15</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb15</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb15</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain15</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant16</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb16</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb16</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain16</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant17</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb17</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb17</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain17</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant18</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb18</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb18</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain18</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant19</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb19</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb19</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain19</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb1</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb1</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain1</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant20</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb20</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb20</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain20</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant21</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb21</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb21</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain21</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant22</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb22</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb22</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain22</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant23</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb23</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb23</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain23</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant24</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb24</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb24</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain24</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant25</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb25</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb25</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain25</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant26</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb26</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb26</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain26</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant27</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb27</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb27</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain27</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant28</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb28</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb28</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain28</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant29</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb29</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb29</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain29</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb2</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb2</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain2</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant30</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb30</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb30</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain30</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant31</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb31</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb31</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain31</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb3</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb3</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain3</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb4</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb4</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain4</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb5</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb5</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain5</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb6</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb6</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain6</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb7</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb7</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain7</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb8</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb8</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain8</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>dc_offs_enb9</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>iq_imbal_enb9</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>norm_gain9</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>clock_rate</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dev_addr</key>
+      <value>addr=192.168.10.2</value>
+    </param>
+    <param>
+      <key>dev_args</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(48, 171)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>uhd_usrp_source_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>clock_source0</key>
+      <value>gpsdo</value>
+    </param>
+    <param>
+      <key>sd_spec0</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source0</key>
+      <value>gpsdo</value>
+    </param>
+    <param>
+      <key>clock_source1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>nchan</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_mboards</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>fc32</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>hide_cmd_port</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>stream_args</key>
+      <value></value>
+    </param>
+    <param>
+      <key>stream_chans</key>
+      <value>[]</value>
+    </param>
+    <param>
+      <key>sync</key>
+      <value></value>
+    </param>
+    <param>
+      <key>otw</key>
+      <value></value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_1</source_block_id>
+    <sink_block_id>packet_rx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>digital_fll_band_edge_cc_0</source_block_id>
+    <sink_block_id>blocks_multiply_const_vxx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_rx_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>pkt out</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_rx_0</source_block_id>
+    <sink_block_id>blocks_tuntap_pdu_0</sink_block_id>
+    <source_key>pkt out</source_key>
+    <sink_key>pdus</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_rx_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0_0_0</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_rx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_1_0_0_1</sink_block_id>
+    <source_key>2</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>uhd_usrp_source_0</source_block_id>
+    <sink_block_id>blocks_multiply_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>uhd_usrp_source_0</source_block_id>
+    <sink_block_id>blocks_multiply_const_vxx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>uhd_usrp_source_0</source_block_id>
+    <sink_block_id>digital_fll_band_edge_cc_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/uhd_packet_tx.grc 
b/gr-digital/examples/packet/uhd_packet_tx.grc
new file mode 100644
index 0000000..2bc5ae7
--- /dev/null
+++ b/gr-digital/examples/packet/uhd_packet_tx.grc
@@ -0,0 +1,3293 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Thu Dec  4 14:34:25 2014</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>2000,2000</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>uhd_packet_tx</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(240, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(400, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_4()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(560, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_4()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(576, 683)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>amp</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.005</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>0.9</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(152, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.22</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_cc_encoder_def</key>
+    <param>
+      <key>padding</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>k</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>1500*8</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 467)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>polys</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>rate</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>state_start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>mode</key>
+      <value>fec.CC_TERMINATED</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 467)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_repetition_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 547)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>rep</key>
+      <value>rep</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(440, 467)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc_hdr</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>483e6-300</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(576, 555)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Frequency</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>50e6</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>500e3</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>3e9</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(448, 683)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>gain</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Gain</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>83</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_header_format_default</key>
+    <param>
+      <key>access_code</key>
+      <value>digital.packet_utils.default_access_code</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(752, 14)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(752, 85)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>value</key>
+      
<value>digital.header_format_counter(digital.packet_utils.default_access_code, 
3, Const_PLD.bits_per_symbol())</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(272, 651)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>7</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(80, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1272, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>ntaps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>len(tx_rrc_taps)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(320, 715)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[109, 79]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(344, 651)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(248, 715)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rep</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1000e3</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(448, 555)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Sample Rate</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>200e3</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>200e3</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>10e6</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(944, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_rrc_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>5*sps*nfilts</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(936, 297)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_strobe</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(32, 203)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_strobe_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>msg</key>
+      <value>pmt.intern("TEST")</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>period</key>
+      <value>2000</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_multiply_const_vxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>amp</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_multiply_const_vxx_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_random_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mask</key>
+      <value>0xff</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(240, 187)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_random_pdu_0</value>
+    </param>
+    <param>
+      <key>length_modulo</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxsize</key>
+      <value>150</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minsize</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tag_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>display</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1472, 275)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tag_debug_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>filter</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value></value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>packet_tx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(496, 163)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>hdr_enc</key>
+      <value>enc_hdr</value>
+    </param>
+    <param>
+      <key>hdr_format</key>
+      
<value>digital.header_format_default(digital.packet_utils.default_access_code, 
0)</value>
+    </param>
+    <param>
+      <key>hdr_const</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>packet_tx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>pld_enc</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>pld_const</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>psf_taps</key>
+      <value>tx_rrc_taps</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1264, 475)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_freq_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>bw</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>fc</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>fftsize</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1264, 395)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_freq_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"dark blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>showports</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>freqhalf</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>wintype</key>
+      <value>firdes.WIN_BLACKMAN_hARRIS</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Relative Gain</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-140</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>dB</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1264, 315)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_1</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>2500</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1096, 11)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>2,0,1,2</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab0</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Freq.</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>uhd_usrp_sink</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ant0</key>
+      <value>TX/RX</value>
+    </param>
+    <param>
+      <key>bw0</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq0</key>
+      <value>uhd.tune_request(freq, samp_rate/2.0)</value>
+    </param>
+    <param>
+      <key>norm_gain0</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain0</key>
+      <value>gain</value>
+    </param>
+    <param>
+      <key>ant10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain10</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant11</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain11</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant12</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain12</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant13</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain13</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant14</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain14</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant15</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain15</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant16</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain16</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant17</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain17</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant18</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain18</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant19</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain19</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain1</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant20</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain20</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant21</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain21</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant22</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain22</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant23</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain23</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant24</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain24</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant25</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain25</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant26</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain26</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant27</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain27</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant28</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain28</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant29</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain29</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain2</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant30</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain30</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant31</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain31</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain3</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain4</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain5</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain6</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain7</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain8</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain9</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>clock_rate</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dev_addr</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>dev_args</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1264, 99)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>uhd_usrp_sink_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>fc32</value>
+    </param>
+    <param>
+      <key>clock_source0</key>
+      <value>gpsdo</value>
+    </param>
+    <param>
+      <key>sd_spec0</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source0</key>
+      <value>gpsdo</value>
+    </param>
+    <param>
+      <key>clock_source1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>nchan</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_mboards</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>hide_cmd_port</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>stream_args</key>
+      <value></value>
+    </param>
+    <param>
+      <key>stream_chans</key>
+      <value>[]</value>
+    </param>
+    <param>
+      <key>sync</key>
+      <value></value>
+    </param>
+    <param>
+      <key>len_tag_name</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>otw</key>
+      <value></value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_message_strobe_0</source_block_id>
+    <sink_block_id>blocks_random_pdu_0</sink_block_id>
+    <source_key>strobe</source_key>
+    <sink_key>generate</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>blocks_tag_debug_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_freq_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>uhd_usrp_sink_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_random_pdu_0</source_block_id>
+    <sink_block_id>packet_tx_0</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_tx_0</source_block_id>
+    <sink_block_id>blocks_multiply_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_tx_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>postcrc</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gr-digital/examples/packet/uhd_packet_tx_tun.grc 
b/gr-digital/examples/packet/uhd_packet_tx_tun.grc
new file mode 100644
index 0000000..95fccd4
--- /dev/null
+++ b/gr-digital/examples/packet/uhd_packet_tx_tun.grc
@@ -0,0 +1,3236 @@
+<?xml version='1.0' encoding='utf-8'?>
+<?grc format='1' created='3.7.10'?>
+<flow_graph>
+  <timestamp>Thu Dec  4 14:34:25 2014</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>2000,2000</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>qt_gui</value>
+    </param>
+    <param>
+      <key>hier_block_src_path</key>
+      <value>.:</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>uhd_packet_tx_tun</value>
+    </param>
+    <param>
+      <key>max_nouts</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>qt_qss_theme</key>
+      <value></value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>run_command</key>
+      <value>{python} -u {filename}</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>thread_safe_setters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(240, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_2()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(400, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_2()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_constellation</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const_points</key>
+      <value>digital.psk_4()[0]</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>calcdist</value>
+    </param>
+    <param>
+      <key>dims</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(560, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>rot_sym</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>soft_dec_lut</key>
+      <value>'auto'</value>
+    </param>
+    <param>
+      <key>precision</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>sym_map</key>
+      <value>digital.psk_4()[1]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(576, 683)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>amp</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>0.005</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>0.9</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(152, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.22</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_cc_encoder_def</key>
+    <param>
+      <key>padding</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>k</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>1500*8</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 467)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>polys</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>rate</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>state_start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>mode</key>
+      <value>fec.CC_TERMINATED</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 467)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_repetition_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 547)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>rep</key>
+      <value>rep</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_dummy_encoder_def</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dim1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>dim2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>framebits</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(440, 467)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>enc_hdr</value>
+    </param>
+    <param>
+      <key>ndim</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>483e6-300</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(576, 555)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,1,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Frequency</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>50e6</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>500e3</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>3e9</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(448, 683)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>1,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>gain</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Gain</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>83</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_header_format_default</key>
+    <param>
+      <key>access_code</key>
+      <value>digital.packet_utils.default_access_code</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(752, 14)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format</value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(752, 85)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>hdr_format_0</value>
+    </param>
+    <param>
+      <key>value</key>
+      
<value>digital.header_format_counter(digital.packet_utils.default_access_code, 
3, Const_PLD.bits_per_symbol())</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(272, 651)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>k</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>7</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(80, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1272, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>ntaps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>len(tx_rrc_taps)</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(320, 715)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>polys</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[109, 79]</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(344, 651)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rate</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(248, 715)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>rep</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_qtgui_range</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1000e3</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(448, 555)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>0,0,1,1</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Sample Rate</value>
+    </param>
+    <param>
+      <key>min_len</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>orient</key>
+      <value>Qt.Horizontal</value>
+    </param>
+    <param>
+      <key>start</key>
+      <value>200e3</value>
+    </param>
+    <param>
+      <key>step</key>
+      <value>200e3</value>
+    </param>
+    <param>
+      <key>stop</key>
+      <value>10e6</value>
+    </param>
+    <param>
+      <key>rangeType</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>widget</key>
+      <value>counter_slider</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(8, 75)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>sps</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_rrc_filter_taps</key>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>eb</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(944, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tx_rrc_taps</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>5*sps*nfilts</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1.0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_message_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(936, 297)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_message_debug_0</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_multiply_const_vxx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>amp</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(952, 211)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_multiply_const_vxx_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tag_debug</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>display</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1472, 275)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tag_debug_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>filter</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value></value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+  </block>
+  <block>
+    <key>blocks_tuntap_pdu</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>istunflag</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(272, 195)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>blocks_tuntap_pdu_0</value>
+    </param>
+    <param>
+      <key>ifn</key>
+      <value>tun0</value>
+    </param>
+    <param>
+      <key>mtu</key>
+      <value>10000</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>packet_tx</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(496, 163)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>hdr_enc</key>
+      <value>enc_hdr</value>
+    </param>
+    <param>
+      <key>hdr_format</key>
+      
<value>digital.header_format_default(digital.packet_utils.default_access_code, 
0)</value>
+    </param>
+    <param>
+      <key>hdr_const</key>
+      <value>Const_HDR</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>packet_tx_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>pld_enc</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>pld_const</key>
+      <value>Const_PLD</value>
+    </param>
+    <param>
+      <key>psf_taps</key>
+      <value>tx_rrc_taps</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>sps</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_const_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1264, 475)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_const_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>xmax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>xmin</key>
+      <value>-2</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_freq_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>bw</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>fc</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>fftsize</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1264, 395)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_freq_sink_x_0</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"dark blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>showports</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>freqhalf</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>wintype</key>
+      <value>firdes.WIN_BLACKMAN_hARRIS</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Relative Gain</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-140</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>dB</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_time_sink_x</key>
+    <param>
+      <key>autoscale</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>axislabels</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ctrlpanel</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>entags</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1264, 315)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>address@hidden</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>qtgui_time_sink_x_1</value>
+    </param>
+    <param>
+      <key>legend</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>alpha1</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color1</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker1</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width1</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha10</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color10</key>
+      <value>"blue"</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker10</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width10</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha2</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color2</key>
+      <value>"red"</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker2</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width2</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha3</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color3</key>
+      <value>"green"</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker3</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width3</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha4</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color4</key>
+      <value>"black"</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker4</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width4</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha5</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color5</key>
+      <value>"cyan"</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker5</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width5</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha6</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color6</key>
+      <value>"magenta"</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker6</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width6</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha7</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color7</key>
+      <value>"yellow"</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker7</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width7</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha8</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color8</key>
+      <value>"dark red"</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker8</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width8</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alpha9</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>color9</key>
+      <value>"dark green"</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>marker9</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>style9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>width9</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>name</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>nconnections</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>2500</value>
+    </param>
+    <param>
+      <key>srate</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>tr_chan</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_delay</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>tr_level</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>tr_mode</key>
+      <value>qtgui.TRIG_MODE_FREE</value>
+    </param>
+    <param>
+      <key>tr_slope</key>
+      <value>qtgui.TRIG_SLOPE_POS</value>
+    </param>
+    <param>
+      <key>tr_tag</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>update_time</key>
+      <value>0.10</value>
+    </param>
+    <param>
+      <key>ylabel</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>yunit</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>ymax</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>ymin</key>
+      <value>-2</value>
+    </param>
+  </block>
+  <block>
+    <key>qtgui_tab_widget</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1096, 11)</value>
+    </param>
+    <param>
+      <key>gui_hint</key>
+      <value>2,0,1,2</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>tab0</value>
+    </param>
+    <param>
+      <key>label0</key>
+      <value>Time</value>
+    </param>
+    <param>
+      <key>label1</key>
+      <value>Freq.</value>
+    </param>
+    <param>
+      <key>label10</key>
+      <value>Tab 10</value>
+    </param>
+    <param>
+      <key>label11</key>
+      <value>Tab 11</value>
+    </param>
+    <param>
+      <key>label12</key>
+      <value>Tab 12</value>
+    </param>
+    <param>
+      <key>label13</key>
+      <value>Tab 13</value>
+    </param>
+    <param>
+      <key>label14</key>
+      <value>Tab 14</value>
+    </param>
+    <param>
+      <key>label15</key>
+      <value>Tab 15</value>
+    </param>
+    <param>
+      <key>label16</key>
+      <value>Tab 16</value>
+    </param>
+    <param>
+      <key>label17</key>
+      <value>Tab 17</value>
+    </param>
+    <param>
+      <key>label18</key>
+      <value>Tab 18</value>
+    </param>
+    <param>
+      <key>label19</key>
+      <value>Tab 19</value>
+    </param>
+    <param>
+      <key>label2</key>
+      <value>Const.</value>
+    </param>
+    <param>
+      <key>label3</key>
+      <value>Tab 3</value>
+    </param>
+    <param>
+      <key>label4</key>
+      <value>Tab 4</value>
+    </param>
+    <param>
+      <key>label5</key>
+      <value>Tab 5</value>
+    </param>
+    <param>
+      <key>label6</key>
+      <value>Tab 6</value>
+    </param>
+    <param>
+      <key>label7</key>
+      <value>Tab 7</value>
+    </param>
+    <param>
+      <key>label8</key>
+      <value>Tab 8</value>
+    </param>
+    <param>
+      <key>label9</key>
+      <value>Tab 9</value>
+    </param>
+    <param>
+      <key>num_tabs</key>
+      <value>3</value>
+    </param>
+  </block>
+  <block>
+    <key>uhd_usrp_sink</key>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ant0</key>
+      <value>TX/RX</value>
+    </param>
+    <param>
+      <key>bw0</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq0</key>
+      <value>uhd.tune_request(freq, samp_rate/2.0)</value>
+    </param>
+    <param>
+      <key>norm_gain0</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain0</key>
+      <value>gain</value>
+    </param>
+    <param>
+      <key>ant10</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain10</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain10</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant11</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain11</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain11</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant12</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain12</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain12</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant13</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain13</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain13</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant14</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain14</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain14</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant15</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain15</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain15</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant16</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain16</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain16</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant17</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain17</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain17</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant18</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain18</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain18</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant19</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain19</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain19</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain1</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain1</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant20</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain20</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain20</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant21</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain21</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain21</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant22</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain22</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain22</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant23</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain23</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain23</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant24</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain24</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain24</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant25</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain25</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain25</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant26</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain26</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain26</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant27</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain27</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain27</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant28</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain28</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain28</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant29</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain29</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain29</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain2</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain2</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant30</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain30</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain30</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant31</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain31</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain31</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain3</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain3</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain4</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain4</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain5</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain5</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain6</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain6</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain7</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain7</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant8</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain8</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain8</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ant9</key>
+      <value></value>
+    </param>
+    <param>
+      <key>bw9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>center_freq9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>norm_gain9</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>gain9</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>clock_rate</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>dev_addr</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>dev_args</key>
+      <value>""</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1264, 99)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>uhd_usrp_sink_0</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>fc32</value>
+    </param>
+    <param>
+      <key>clock_source0</key>
+      <value>gpsdo</value>
+    </param>
+    <param>
+      <key>sd_spec0</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source0</key>
+      <value>gpsdo</value>
+    </param>
+    <param>
+      <key>clock_source1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source1</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source2</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source3</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source4</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source5</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source6</key>
+      <value></value>
+    </param>
+    <param>
+      <key>clock_source7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>sd_spec7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>time_source7</key>
+      <value></value>
+    </param>
+    <param>
+      <key>nchan</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_mboards</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>hide_cmd_port</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>stream_args</key>
+      <value></value>
+    </param>
+    <param>
+      <key>stream_chans</key>
+      <value>[]</value>
+    </param>
+    <param>
+      <key>sync</key>
+      <value></value>
+    </param>
+    <param>
+      <key>len_tag_name</key>
+      <value>packet_len</value>
+    </param>
+    <param>
+      <key>otw</key>
+      <value></value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>blocks_tag_debug_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_const_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_freq_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>qtgui_time_sink_x_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>uhd_usrp_sink_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blocks_tuntap_pdu_0</source_block_id>
+    <sink_block_id>packet_tx_0</sink_block_id>
+    <source_key>pdus</source_key>
+    <sink_key>in</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_tx_0</source_block_id>
+    <sink_block_id>blocks_multiply_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>packet_tx_0</source_block_id>
+    <sink_block_id>blocks_message_debug_0</sink_block_id>
+    <source_key>postcrc</source_key>
+    <sink_key>print_pdu</sink_key>
+  </connection>
+</flow_graph>



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