[Commit-gnuradio] r4771 - gnuradio/branches/developers/jcorgan/channel/gnuradio-examples/python/hier/sounder

[jcorgan]

Author: jcorgan
Date: 2007-03-17 19:10:16 -0600 (Sat, 17 Mar 2007)
New Revision: 4771

Modified:
   
gnuradio/branches/developers/jcorgan/channel/gnuradio-examples/python/hier/sounder/sounder_rx.py
Log:
Work in progress, calculating impulse response and sinking to file.

Modified: 
gnuradio/branches/developers/jcorgan/channel/gnuradio-examples/python/hier/sounder/sounder_rx.py
===================================================================
--- 
gnuradio/branches/developers/jcorgan/channel/gnuradio-examples/python/hier/sounder/sounder_rx.py
    2007-03-18 00:34:26 UTC (rev 4770)
+++ 
gnuradio/branches/developers/jcorgan/channel/gnuradio-examples/python/hier/sounder/sounder_rx.py
    2007-03-18 01:10:16 UTC (rev 4771)
@@ -46,8 +46,8 @@
         self._output_rate = output_rate
         self._verbose = verbose
         min_chips = int(math.ceil(2.0*self._max_delay * self._chip_rate))
-        degree = int(math.ceil(math.log(min_chips)/math.log(2)))
-        self._length = 2**degree-1
+        self._degree = int(math.ceil(math.log(min_chips)/math.log(2)))
+        self._length = 2**self._degree-1
         self._rep_rate = self._chip_rate/float(self._length)
         self._decim = int(self._rep_rate/self._output_rate)
         self._output_rate = self._rep_rate
@@ -55,23 +55,57 @@
 
         if self._verbose:
             print "Mininum sequence length needed is", n2s(min_chips), "chips"
-            print "Using PN sequence of degree", degree, "length", self._length
+            print "Using PN sequence of degree", self._degree, "length", 
self._length
             print "Sequence repetition rate is", n2s(self._rep_rate), "per sec"
             print "Smoothing time constant is", n2s(self._tc), "sec"
             print "IIR tap is", n2s(self._tap)
             print "Using sequence decimation of", self._decim
             print "Sequence output rate is", n2s(self._rep_rate/self._decim)
         
-        self.define_component("s2v", gr.stream_to_vector(gr.sizeof_gr_complex, 
self._length))
+        self._generate_reference()
+
+        self.define_component("s2v-1", 
gr.stream_to_vector(gr.sizeof_gr_complex, self._length))
         self.define_component("fft", gr.fft_vcc(self._length, True, ())) # No 
window needed
         self.define_component("avg", gr.single_pole_iir_filter_cc(self._tap, 
self._length))
         self.define_component("decim", 
gr.keep_one_in_n(gr.sizeof_gr_complex*self._length, self._decim))
-        self.define_component("sink", 
gr.file_sink(gr.sizeof_gr_complex*self._length, "FFT.dat"))
-
-        # Ultimately this will be
-        # self.connect("self s2v fft avg decim sink")
-        self.connect("self", 0, "s2v", 0)
-        self.connect("s2v", 0, "fft", 0)
+        self.define_component("ref", gr.vector_source_c(self._reference, True))
+        self.define_component("s2v-2", 
gr.stream_to_vector(gr.sizeof_gr_complex, self._length))
+        self.define_component("mult", gr.multiply_vcc(self._length))
+        self.define_component("ifft", gr.fft_vcc(self._length, False, ())) # 
No window needed
+        self.define_component("sink", 
gr.file_sink(gr.sizeof_gr_complex*self._length, "impulse.dat"))
+        
+        # Averaged FFT leg
+        self.connect("self", 0, "s2v-1", 0)
+        self.connect("s2v-1", 0, "fft", 0)
         self.connect("fft", 0, "avg", 0)
         self.connect("avg", 0, "decim", 0)
-        self.connect("decim", 0, "sink", 0)
+
+        # FFT correlation leg
+        self.connect("decim", 0, "mult", 0)
+        self.connect("ref", 0, "s2v-2", 0)
+        self.connect("s2v-2", 0, "mult", 1)
+        self.connect("mult", 0, "ifft", 0)
+        self.connect("ifft", 0, "sink", 0)
+
+    def _generate_reference(self):
+        # Create a temporary flowgraph to generate conjugate FFT of LFSR output
+        hb = gr.hier_block2("temp_block", gr.io_signature(0,0,0), 
gr.io_signature(0,0,0))
+        hb.define_component("glfsr", gr.glfsr_source_b(self._degree))
+        hb.define_component("head", gr.head(gr.sizeof_char, self._length))
+       hb.define_component("mapper", gr.chunks_to_symbols_bf((-1.0, 1.0), 1))
+        hb.define_component("s2v", gr.stream_to_vector(gr.sizeof_float, 
self._length))
+        hb.define_component("fft", gr.fft_vfc(self._length, True, ())) # No 
window needed
+        hb.define_component("v2s", gr.vector_to_stream(gr.sizeof_gr_complex, 
self._length))
+        hb.define_component("conj", gr.conjugate_cc())
+        sink = gr.vector_sink_c()
+        hb.define_component("sink", sink)
+        hb.connect("glfsr", 0, "head", 0)
+        hb.connect("head", 0, "mapper", 0)
+        hb.connect("mapper", 0, "s2v", 0)
+        hb.connect("s2v", 0, "fft", 0)
+        hb.connect("fft", 0, "v2s", 0)
+        hb.connect("v2s", 0, "conj", 0)
+        hb.connect("conj", 0, "sink", 0)
+        r = gr.runtime(hb)
+        r.run()
+        self._reference = sink.data()