[Commit-gnuradio] r8213 - gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl

[trondeau]

Author: trondeau
Date: 2008-04-16 11:12:13 -0600 (Wed, 16 Apr 2008)
New Revision: 8213

Modified:
   gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_receiver.py
   gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_sync_fixed.py
Log:
to complete what I started, this makes the ofdm_sync_fixed block work again in 
the OFDM receiver. Its only used for testing in the simulation mode if you want 
to remove any affects of the synchronization blocks. You have to manually edit 
the number of symbols and any fractional frequency offset you might want to use.

Modified: 
gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_receiver.py
===================================================================
--- gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_receiver.py 
2008-04-16 16:22:41 UTC (rev 8212)
+++ gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_receiver.py 
2008-04-16 17:12:13 UTC (rev 8213)
@@ -93,9 +93,12 @@
         elif SYNC == "pnac":
             nco_sensitivity = -2.0/fft_length                             # 
correct for fine frequency
             self.ofdm_sync = ofdm_sync_pnac(fft_length, cp_length, ks0time, 
logging)
-        elif SYNC == "fixed":
+        elif SYNC == "fixed":                                             # 
for testing only; do not user over the air
+            self.chan_filt = gr.multiply_const_cc(1.0)                    # 
remove filter and filter delay for this
+            nsymbols = 18                                                 # 
enter the number of symbols per packet
+            freq_offset = 0.0                                             # if 
you use a frequency offset, enter it here
             nco_sensitivity = -2.0/fft_length                             # 
correct for fine frequency
-            self.ofdm_sync = ofdm_sync_fixed(fft_length, cp_length, logging)
+            self.ofdm_sync = ofdm_sync_fixed(fft_length, cp_length, nsymbols, 
freq_offset, logging)
 
         # Set up blocks
 

Modified: 
gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_sync_fixed.py
===================================================================
--- 
gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_sync_fixed.py   
    2008-04-16 16:22:41 UTC (rev 8212)
+++ 
gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/ofdm_sync_fixed.py   
    2008-04-16 17:12:13 UTC (rev 8213)
@@ -24,26 +24,27 @@
 from gnuradio import gr
 
 class ofdm_sync_fixed(gr.hier_block2):
-    def __init__(self, fft_length, cp_length, logging=False):
+    def __init__(self, fft_length, cp_length, nsymbols, freq_offset, 
logging=False):
 
         gr.hier_block2.__init__(self, "ofdm_sync_fixed",
                                gr.io_signature(1, 1, gr.sizeof_gr_complex), # 
Input signature
-                               gr.io_signature2(2, 2, 
gr.sizeof_gr_complex*fft_length, gr.sizeof_char)) # Output signature
+                               gr.io_signature2(2, 2, gr.sizeof_float, 
gr.sizeof_char)) # Output signature
 
         # Use a fixed trigger point instead of sync block
         symbol_length = fft_length + cp_length
-        data = (symbol_length)*[0,]
+        pkt_length = nsymbols*symbol_length
+        data = (pkt_length)*[0,]
         data[(symbol_length)-1] = 1
         self.peak_trigger = gr.vector_source_b(data, True)
-        self.sampler = gr.ofdm_sampler(fft_length, symbol_length)
 
-        self.connect(self, (self.sampler,0))
-        self.connect(self.peak_trigger, (self.sampler,1))
-        self.connect(self.sampler, (self,0))
+        # Use a pre-defined frequency offset
+        foffset = (pkt_length)*[math.pi*freq_offset,]
+        self.frequency_offset = gr.vector_source_f(foffset, True)
+
+        self.connect(self, gr.null_sink(gr.sizeof_gr_complex))
+        self.connect(self.frequency_offset, (self,0))
         self.connect(self.peak_trigger, (self,1))
 
         if logging:
             self.connect(self.peak_trigger, gr.file_sink(gr.sizeof_char, 
"ofdm_sync_fixed-peaks_b.dat"))
-            self.connect(self.sampler, 
gr.file_sink(gr.sizeof_gr_complex*fft_length,
-                                                    
"ofdm_sync_fixed-sampler_c.dat"))