Adds frequency accessor for Costas loop, BERT receiver displays frequency and timing offset

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@9576 221aa14e-8319-0410-a670-987f0aec2ac5

2 files changed, 31 insertions, 23 deletions

diff --git a/gnuradio-examples/python/digital-bert/benchmark_rx.py b/gnuradio-examples/python/digital-bert/benchmark_rx.py
index 96bf7fa12..1e00dbd76 100755
--- a/gnuradio-examples/python/digital-bert/benchmark_rx.py
+++ b/gnuradio-examples/python/digital-bert/benchmark_rx.py
@@ -39,8 +39,8 @@ class status_thread(_threading.Thread):
 
     def run(self):
         while not self.done:
-            print "Magnitude: %5.3f  Variance: %5.3f  Estimated SNR: %4.1f dB  BER: %g" % (
-                tb.mag(), tb.var(), tb.snr(), tb.ber())
+            print "Freq. Offset: %5.0f Hz  Timing Offset: %5.1f ppm  Estimated SNR: %4.1f dB  BER: %g" % (
+                tb.frequency_offset(), tb.timing_offset()*1e6, tb.snr(), tb.ber())
             try:
                 time.sleep(1.0)
             except KeyboardInterrupt:
@@ -104,6 +104,12 @@ class rx_bpsk_block(gr.top_block):
 
     def ber(self):
         return self._receiver.ber()
+
+    def frequency_offset(self):
+        return self._receiver.frequency_offset()
+        
+    def timing_offset(self):
+        return self._receiver.timing_offset()
             
 def get_options():
     parser = OptionParser(option_class=eng_option)
@@ -122,17 +128,17 @@ def get_options():
                       help="Select USRP decimation rate (default=%default)")
     parser.add_option("", "--excess-bw", type="eng_float", default=0.35,
                       help="Select RRC excess bandwidth (default=%default)")
-    parser.add_option("", "--costas-alpha", type="eng_float", default=0.2,
+    parser.add_option("", "--costas-alpha", type="eng_float", default=0.05,
                       help="set Costas loop 1st order gain, (default=%default)")
-    parser.add_option("", "--costas-beta", type="eng_float", default=0.01,
+    parser.add_option("", "--costas-beta", type="eng_float", default=0.00025,
                       help="set Costas loop 2nd order gain, (default=%default)")
-    parser.add_option("", "--costas-max", type="eng_float", default=0.005,
+    parser.add_option("", "--costas-max", type="eng_float", default=0.05,
                       help="set Costas loop max freq (rad/sample) (default=%default)")
-    parser.add_option("", "--mm-gain-mu", type="eng_float", default=0.2,
+    parser.add_option("", "--mm-gain-mu", type="eng_float", default=0.001,
                       help="set M&M loop 1st order gain, (default=%default)")
-    parser.add_option("", "--mm-gain-omega", type="eng_float", default=0.01,
+    parser.add_option("", "--mm-gain-omega", type="eng_float", default=0.000001,
                       help="set M&M loop 2nd order gain, (default=%default)")
-    parser.add_option("", "--mm-omega-limit", type="eng_float", default=0.005,
+    parser.add_option("", "--mm-omega-limit", type="eng_float", default=0.0001,
                       help="set M&M max timing error, (default=%default)")
 
 		      
diff --git a/gnuradio-examples/python/digital-bert/receive_path.py b/gnuradio-examples/python/digital-bert/receive_path.py
index 84ff32916..e273923a4 100644
--- a/gnuradio-examples/python/digital-bert/receive_path.py
+++ b/gnuradio-examples/python/digital-bert/receive_path.py
@@ -41,21 +41,22 @@ class receive_path(gr.hier_block2):
                                 gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
                                 gr.io_signature(0, 0, 0))                    # Output signature
 
-        sps = int(if_rate/symbol_rate)
-        print "IF sample rate:", n2s(if_rate)
+        self._if_rate = if_rate
+        self._sps = int(self._if_rate/symbol_rate)
+        print "IF sample rate:", n2s(self._if_rate)
         print "Symbol rate:", n2s(symbol_rate)
-        print "Samples/symbol:", sps
+        print "Samples/symbol:", self._sps
         print "RRC bandwidth:", excess_bw
         
         # Create AGC to scale input to unity
         self._agc = gr.agc_cc(1e-5, 1.0, 1.0, 1.0)
 
 	# Create RRC with specified excess bandwidth
-	taps = gr.firdes.root_raised_cosine(1.0,       # Gain
-					    sps,       # Sampling rate
-					    1.0,       # Symbol rate
-					    excess_bw, # Roll-off factor
-					    11*sps)    # Number of taps
+	taps = gr.firdes.root_raised_cosine(1.0,          # Gain
+					    self._sps,    # Sampling rate
+					    1.0,          # Symbol rate
+					    excess_bw,    # Roll-off factor
+					    11*self._sps) # Number of taps
 
 	self._rrc = gr.fir_filter_ccf(1, taps)
         
@@ -73,7 +74,7 @@ class receive_path(gr.hier_block2):
 
         # Create a M&M bit synchronization retiming block
         mm_mu = 0.5
-        mm_omega = sps
+        mm_omega = self._sps
 
         print "MM gain mu:", mm_gain_mu
         print "MM gain omega:", mm_gain_omega
@@ -103,14 +104,15 @@ class receive_path(gr.hier_block2):
         self.connect(self, self._agc, self._rrc, self._costas, self._mm, 
                      self._c2r, self._slicer, self._descrambler, self._ber)
 
+    def frequency_offset(self):
+        return self._costas.freq()*self._if_rate/(2*math.pi)
+
+    def timing_offset(self):
+        return self._mm.omega()/self._sps-1.0
+
     def snr(self):
         return self._snr_probe.snr()
 
-    def signal_mean(self):
-        return self._snr_probe.signal_mean()
-        
-    def noise_variance(self):
-        return self._snr_probe.noise_variance()
-
     def ber(self):
         return (1.0-self._ber.density())/3.0
+