Merge branch 'digital' of git@gnuradio.org:trondeau into digital

Conflicts:
	gnuradio-examples/python/digital/benchmark_qt_rx2.py

9 files changed, 258 insertions, 239 deletions

diff --git a/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.cc b/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.cc
index 030e45ddf..7f2c468b7 100644
--- a/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.cc
+++ b/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.cc
@@ -53,7 +53,7 @@ gr_fll_band_edge_cc_sptr gr_make_fll_band_edge_cc (float samps_per_sym, float ro
 }
 
 
-static int ios[] = {sizeof(gr_complex), sizeof(float), sizeof(float), sizeof(float)};
+static int ios[] = {sizeof(gr_complex), sizeof(float), sizeof(float), sizeof(gr_complex)};
 static std::vector<int> iosig(ios, ios+sizeof(ios)/sizeof(int));
 gr_fll_band_edge_cc::gr_fll_band_edge_cc (float samps_per_sym, float rolloff,
 					  int filter_size, float alpha, float beta)
@@ -83,10 +83,11 @@ gr_fll_band_edge_cc::~gr_fll_band_edge_cc ()
 void
 gr_fll_band_edge_cc::set_alpha(float alpha) 
 { 
-  float eta = sqrt(2.0)/2.0;
-  float theta = alpha;
-  d_alpha = (4*eta*theta) / (1.0 + 2.0*eta*theta + theta*theta);
-  d_beta = (4*theta*theta) / (1.0 + 2.0*eta*theta + theta*theta);
+  //float eta = sqrt(2.0)/2.0;
+  //float theta = alpha;
+  //d_alpha = (4*eta*theta) / (1.0 + 2.0*eta*theta + theta*theta);
+  //d_beta = (4*theta*theta) / (1.0 + 2.0*eta*theta + theta*theta);
+  d_alpha = alpha;
 }
 
 void
@@ -160,11 +161,12 @@ gr_fll_band_edge_cc::work (int noutput_items,
   const gr_complex *in  = (const gr_complex *) input_items[0];
   gr_complex *out = (gr_complex *) output_items[0];
 
-  float *frq, *phs, *err;
+  float *frq, *phs;
+  gr_complex *err;
   if(output_items.size() > 2) {
     frq = (float *) output_items[1];
     phs = (float *) output_items[2];
-    err = (float *) output_items[3];
+    err = (gr_complex *) output_items[3];
   }
 
   if (d_updated) {
@@ -174,16 +176,17 @@ gr_fll_band_edge_cc::work (int noutput_items,
 
   int i;
   gr_complex nco_out;
-  float out_upper, out_lower;
+  gr_complex out_upper, out_lower;
   float error;
+  float avg_k = 0.1;
   for(i = 0; i < noutput_items; i++) {
     nco_out = gr_expj(d_phase);
     out[i] = in[i] * nco_out;
 
-    out_upper = norm(d_filter_upper->filter(&out[i]));
-    out_lower = norm(d_filter_lower->filter(&out[i]));
-    error = out_lower - out_upper;
-    d_error = 0.01*error + 0.99*d_error;  // average error
+    out_upper = (d_filter_upper->filter(&out[i]));
+    out_lower = (d_filter_lower->filter(&out[i]));
+    error = -real((out_upper + out_lower) * conj(out_upper - out_lower));
+    d_error = avg_k*error + avg_k*d_error;  // average error
 
     d_freq = d_freq + d_beta * d_error;
     d_phase = d_phase + d_freq + d_alpha * d_error;
diff --git a/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.h b/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.h
index 09baf7fde..178e18f3e 100644
--- a/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.h
+++ b/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.h
@@ -45,8 +45,12 @@ class gri_fft_complex;
  * (e.g., rolloff factor) of the modulated signal. The placement in frequency of the band-edges
  * is determined by the oversampling ratio (number of samples per symbol) and the excess bandwidth.
  * The size of the filters should be fairly large so as to average over a number of symbols.
- * The FLL works by calculating the power in both the upper and lower bands and comparing them. The
- * difference in power between the filters is proportional to the frequency offset.
+ *
+ * The FLL works by filtering the upper and lower band edges into x_u(t) and x_l(t), respectively.
+ * These are combined to form cc(t) = x_u(t) + x_l(t) and ss(t) = x_u(t) - x_l(t). Combining
+ * these to form the signal e(t) = Re{cc(t) \times ss(t)^*} (where ^* is the complex conjugate)
+ * provides an error signal at the DC term that is directly proportional to the carrier frequency.
+ * We then make a second-order loop using the error signal that is the running average of e(t).
  *
  * In theory, the band-edge filter is the derivative of the matched filter in frequency, 
  * (H_be(f) = \frac{H(f)}{df}. In practice, this comes down to a quarter sine wave at the point
diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py b/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py
index 1d1bfc298..135b38e1f 100644
--- a/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py
+++ b/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py
@@ -38,7 +38,7 @@ _def_gray_code = True
 _def_verbose = False
 _def_log = False
 
-_def_freq_alpha = 4e-3
+_def_freq_alpha = 0.010
 _def_costas_alpha = 0.1
 _def_timing_alpha = 0.100
 _def_timing_beta = 0.010
@@ -226,7 +226,7 @@ class dbpsk2_demod(gr.hier_block2):
         self._samples_per_symbol = samples_per_symbol
         self._excess_bw = excess_bw
         self._freq_alpha = freq_alpha
-        self._freq_beta = 0.25*self._freq_alpha**2
+        self._freq_beta = 0.10*self._freq_alpha
         self._costas_alpha = costas_alpha
         self._timing_alpha = timing_alpha
         self._timing_beta = _def_timing_beta
@@ -308,11 +308,11 @@ class dbpsk2_demod(gr.hier_block2):
         print "bits per symbol:     %d"   % self.bits_per_symbol()
         print "Gray code:           %s"   % self._gray_code
         print "RRC roll-off factor: %.2f" % self._excess_bw
-        print "FLL gain:            %.2f" % self._freq_alpha
-        print "Costas Loop alpha:   %.2f" % self._costas_alpha
-        print "Costas Loop beta:    %.2f" % self._costas_beta
-        print "Timing alpha gain:   %.2f" % self._timing_alpha
-        print "Timing beta gain:    %.2f" % self._timing_beta
+        print "FLL gain:            %.2e" % self._freq_alpha
+        print "Costas Loop alpha:   %.2e" % self._costas_alpha
+        print "Costas Loop beta:    %.2e" % self._costas_beta
+        print "Timing alpha gain:   %.2e" % self._timing_alpha
+        print "Timing beta gain:    %.2e" % self._timing_beta
         print "Timing max dev:      %.2f" % self._timing_max_dev
 
     def _setup_logging(self):
diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/dqpsk2.py b/gnuradio-core/src/python/gnuradio/blks2impl/dqpsk2.py
index 81dccc2eb..f852a324c 100644
--- a/gnuradio-core/src/python/gnuradio/blks2impl/dqpsk2.py
+++ b/gnuradio-core/src/python/gnuradio/blks2impl/dqpsk2.py
@@ -38,7 +38,7 @@ _def_gray_code = True
 _def_verbose = False
 _def_log = False
 
-_def_freq_alpha = 4e-3
+_def_freq_alpha = 0.010
 _def_costas_alpha = 0.01
 _def_timing_alpha = 0.100
 _def_timing_beta = 0.010
diff --git a/gnuradio-examples/grc/demod/digital_freq_lock.grc b/gnuradio-examples/grc/demod/digital_freq_lock.grc
index 37ee8123e..36037febb 100644
--- a/gnuradio-examples/grc/demod/digital_freq_lock.grc
+++ b/gnuradio-examples/grc/demod/digital_freq_lock.grc
@@ -1,6 +1,6 @@
 <?xml version='1.0' encoding='ASCII'?>
 <flow_graph>
-  <timestamp>Fri Jan 29 18:10:00 2010</timestamp>
+  <timestamp>Sat Mar  6 17:17:12 2010</timestamp>
   <block>
     <key>options</key>
     <param>
@@ -980,54 +980,50 @@
     </param>
   </block>
   <block>
-    <key>variable_slider</key>
+    <key>root_raised_cosine_filter</key>
     <param>
       <key>id</key>
-      <value>alpha</value>
+      <value>root_raised_cosine_filter_0</value>
     </param>
     <param>
       <key>_enabled</key>
       <value>True</value>
     </param>
     <param>
-      <key>label</key>
-      <value>Freq Alpha</value>
-    </param>
-    <param>
-      <key>value</key>
-      <value>0</value>
+      <key>type</key>
+      <value>interp_fir_filter_ccf</value>
     </param>
     <param>
-      <key>min</key>
-      <value>0</value>
+      <key>decim</key>
+      <value>1</value>
     </param>
     <param>
-      <key>max</key>
-      <value>0.001</value>
+      <key>interp</key>
+      <value>spb_gen</value>
     </param>
     <param>
-      <key>num_steps</key>
-      <value>1000</value>
+      <key>gain</key>
+      <value>2*spb_gen</value>
     </param>
     <param>
-      <key>style</key>
-      <value>wx.SL_HORIZONTAL</value>
+      <key>samp_rate</key>
+      <value>1.0</value>
     </param>
     <param>
-      <key>converver</key>
-      <value>float_converter</value>
+      <key>sym_rate</key>
+      <value>1./spb_gen</value>
     </param>
     <param>
-      <key>grid_pos</key>
-      <value></value>
+      <key>alpha</key>
+      <value>rolloff</value>
     </param>
     <param>
-      <key>notebook</key>
-      <value></value>
+      <key>ntaps</key>
+      <value>44</value>
     </param>
     <param>
       <key>_coordinate</key>
-      <value>(552, 4)</value>
+      <value>(978, 157)</value>
     </param>
     <param>
       <key>_rotation</key>
@@ -1035,105 +1031,81 @@
     </param>
   </block>
   <block>
-    <key>variable_slider</key>
+    <key>gr_fll_band_edge_cc</key>
     <param>
       <key>id</key>
-      <value>beta</value>
+      <value>gr_fll_band_edge_cc_0</value>
     </param>
     <param>
       <key>_enabled</key>
       <value>True</value>
     </param>
     <param>
-      <key>label</key>
-      <value>Freq Beta</value>
-    </param>
-    <param>
-      <key>value</key>
-      <value>0</value>
-    </param>
-    <param>
-      <key>min</key>
-      <value>0.0</value>
-    </param>
-    <param>
-      <key>max</key>
-      <value>0.0001</value>
+      <key>type</key>
+      <value>cc</value>
     </param>
     <param>
-      <key>num_steps</key>
-      <value>1000</value>
+      <key>samps_per_sym</key>
+      <value>spb_gen</value>
     </param>
     <param>
-      <key>style</key>
-      <value>wx.SL_HORIZONTAL</value>
+      <key>rolloff</key>
+      <value>rolloff</value>
     </param>
     <param>
-      <key>converver</key>
-      <value>float_converter</value>
+      <key>filter_size</key>
+      <value>44</value>
     </param>
     <param>
-      <key>grid_pos</key>
-      <value></value>
+      <key>alpha</key>
+      <value>alpha</value>
     </param>
     <param>
-      <key>notebook</key>
-      <value></value>
+      <key>beta</key>
+      <value>beta</value>
     </param>
     <param>
       <key>_coordinate</key>
-      <value>(668, 5)</value>
+      <value>(874, 664)</value>
     </param>
     <param>
       <key>_rotation</key>
-      <value>180</value>
+      <value>0</value>
     </param>
   </block>
   <block>
-    <key>root_raised_cosine_filter</key>
+    <key>gr_channel_model</key>
     <param>
       <key>id</key>
-      <value>root_raised_cosine_filter_0</value>
+      <value>gr_channel_model_0</value>
     </param>
     <param>
       <key>_enabled</key>
       <value>True</value>
     </param>
     <param>
-      <key>type</key>
-      <value>interp_fir_filter_ccf</value>
-    </param>
-    <param>
-      <key>decim</key>
-      <value>1</value>
-    </param>
-    <param>
-      <key>interp</key>
-      <value>spb_gen</value>
+      <key>noise_voltage</key>
+      <value>noise_amp</value>
     </param>
     <param>
-      <key>gain</key>
-      <value>2*spb_gen</value>
+      <key>freq_offset</key>
+      <value>freq_offset</value>
     </param>
     <param>
-      <key>samp_rate</key>
+      <key>epsilon</key>
       <value>1.0</value>
     </param>
     <param>
-      <key>sym_rate</key>
-      <value>1./spb_gen</value>
-    </param>
-    <param>
-      <key>alpha</key>
-      <value>rolloff</value>
+      <key>taps</key>
+      <value>1.0</value>
     </param>
     <param>
-      <key>ntaps</key>
-      <value>44</value>
+      <key>seed</key>
+      <value>42</value>
     </param>
     <param>
       <key>_coordinate</key>
-      <value>(978, 157)</value>
+      <value>(618, 376)</value>
     </param>
     <param>
       <key>_rotation</key>
@@ -1141,81 +1113,109 @@
     </param>
   </block>
   <block>
-    <key>gr_fll_band_edge_cc</key>
+    <key>variable_slider</key>
     <param>
       <key>id</key>
-      <value>gr_fll_band_edge_cc_0</value>
+      <value>beta</value>
     </param>
     <param>
       <key>_enabled</key>
       <value>True</value>
     </param>
     <param>
-      <key>type</key>
-      <value>cc</value>
+      <key>label</key>
+      <value>Freq Beta</value>
     </param>
     <param>
-      <key>samps_per_sym</key>
-      <value>spb_gen</value>
+      <key>value</key>
+      <value>0</value>
     </param>
     <param>
-      <key>rolloff</key>
-      <value>rolloff</value>
+      <key>min</key>
+      <value>0.0</value>
     </param>
     <param>
-      <key>filter_size</key>
-      <value>44</value>
+      <key>max</key>
+      <value>0.01</value>
     </param>
     <param>
-      <key>alpha</key>
-      <value>alpha</value>
+      <key>num_steps</key>
+      <value>1000</value>
     </param>
     <param>
-      <key>beta</key>
-      <value>beta</value>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
     </param>
     <param>
       <key>_coordinate</key>
-      <value>(874, 664)</value>
+      <value>(668, 5)</value>
     </param>
     <param>
       <key>_rotation</key>
-      <value>0</value>
+      <value>180</value>
     </param>
   </block>
   <block>
-    <key>gr_channel_model</key>
+    <key>variable_slider</key>
     <param>
       <key>id</key>
-      <value>gr_channel_model_0</value>
+      <value>alpha</value>
     </param>
     <param>
       <key>_enabled</key>
       <value>True</value>
     </param>
     <param>
-      <key>noise_voltage</key>
-      <value>noise_amp</value>
+      <key>label</key>
+      <value>Freq Alpha</value>
     </param>
     <param>
-      <key>freq_offset</key>
-      <value>freq_offset</value>
+      <key>value</key>
+      <value>0</value>
     </param>
     <param>
-      <key>epsilon</key>
-      <value>1.0</value>
+      <key>min</key>
+      <value>0</value>
     </param>
     <param>
-      <key>taps</key>
-      <value>1.0</value>
+      <key>max</key>
+      <value>0.1</value>
     </param>
     <param>
-      <key>seed</key>
-      <value>42</value>
+      <key>num_steps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
     </param>
     <param>
       <key>_coordinate</key>
-      <value>(618, 376)</value>
+      <value>(552, 4)</value>
     </param>
     <param>
       <key>_rotation</key>
diff --git a/gnuradio-examples/grc/demod/pam_sync.grc b/gnuradio-examples/grc/demod/pam_sync.grc
index 80a7aef0c..8571995a5 100644
--- a/gnuradio-examples/grc/demod/pam_sync.grc
+++ b/gnuradio-examples/grc/demod/pam_sync.grc
@@ -1,6 +1,6 @@
 <?xml version='1.0' encoding='ASCII'?>
 <flow_graph>
-  <timestamp>Mon Feb  1 18:58:32 2010</timestamp>
+  <timestamp>Sat Mar  6 17:17:22 2010</timestamp>
   <block>
     <key>options</key>
     <param>
@@ -713,116 +713,6 @@
     <key>variable_slider</key>
     <param>
       <key>id</key>
-      <value>freq_beta</value>
-    </param>
-    <param>
-      <key>_enabled</key>
-      <value>True</value>
-    </param>
-    <param>
-      <key>label</key>
-      <value>Freq Beta</value>
-    </param>
-    <param>
-      <key>value</key>
-      <value>0</value>
-    </param>
-    <param>
-      <key>min</key>
-      <value>0.0</value>
-    </param>
-    <param>
-      <key>max</key>
-      <value>0.0001</value>
-    </param>
-    <param>
-      <key>num_steps</key>
-      <value>1000</value>
-    </param>
-    <param>
-      <key>style</key>
-      <value>wx.SL_HORIZONTAL</value>
-    </param>
-    <param>
-      <key>converver</key>
-      <value>float_converter</value>
-    </param>
-    <param>
-      <key>grid_pos</key>
-      <value></value>
-    </param>
-    <param>
-      <key>notebook</key>
-      <value></value>
-    </param>
-    <param>
-      <key>_coordinate</key>
-      <value>(836, 9)</value>
-    </param>
-    <param>
-      <key>_rotation</key>
-      <value>180</value>
-    </param>
-  </block>
-  <block>
-    <key>variable_slider</key>
-    <param>
-      <key>id</key>
-      <value>freq_alpha</value>
-    </param>
-    <param>
-      <key>_enabled</key>
-      <value>True</value>
-    </param>
-    <param>
-      <key>label</key>
-      <value>Freq Alpha</value>
-    </param>
-    <param>
-      <key>value</key>
-      <value>0</value>
-    </param>
-    <param>
-      <key>min</key>
-      <value>0</value>
-    </param>
-    <param>
-      <key>max</key>
-      <value>0.001</value>
-    </param>
-    <param>
-      <key>num_steps</key>
-      <value>1000</value>
-    </param>
-    <param>
-      <key>style</key>
-      <value>wx.SL_HORIZONTAL</value>
-    </param>
-    <param>
-      <key>converver</key>
-      <value>float_converter</value>
-    </param>
-    <param>
-      <key>grid_pos</key>
-      <value></value>
-    </param>
-    <param>
-      <key>notebook</key>
-      <value></value>
-    </param>
-    <param>
-      <key>_coordinate</key>
-      <value>(734, 10)</value>
-    </param>
-    <param>
-      <key>_rotation</key>
-      <value>0</value>
-    </param>
-  </block>
-  <block>
-    <key>variable_slider</key>
-    <param>
-      <key>id</key>
       <value>phase_alpha</value>
     </param>
     <param>
@@ -1621,6 +1511,116 @@
       <value>0</value>
     </param>
   </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>freq_alpha</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Freq Alpha</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>0.1</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(734, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>freq_beta</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Freq Beta</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>0.01</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(836, 9)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
   <connection>
     <source_block_id>random_source_x_0</source_block_id>
     <sink_block_id>gr_uchar_to_float_0</sink_block_id>
diff --git a/gnuradio-examples/python/digital/benchmark_loopback.py b/gnuradio-examples/python/digital/benchmark_loopback.py
index 4cc4a7bee..47e4f2028 100755
--- a/gnuradio-examples/python/digital/benchmark_loopback.py
+++ b/gnuradio-examples/python/digital/benchmark_loopback.py
@@ -44,6 +44,11 @@ class my_top_block(gr.top_block):
         noise_power = power_in_signal/SNR
         noise_voltage = math.sqrt(noise_power)
 
+        # With new interface, sps does not get set by default, but
+        # in the loopback, we don't recalculate it; so just force it here
+        if(options.samples_per_symbol == None):
+            options.samples_per_symbol = 2
+
         self.txpath = transmit_path(mod_class, options)
         self.throttle = gr.throttle(gr.sizeof_gr_complex, options.sample_rate)
         self.rxpath = receive_path(demod_class, rx_callback, options)
diff --git a/gnuradio-examples/python/digital/benchmark_qt_loopback2.py b/gnuradio-examples/python/digital/benchmark_qt_loopback2.py
index 1cb95198e..1f236fd7f 100755
--- a/gnuradio-examples/python/digital/benchmark_qt_loopback2.py
+++ b/gnuradio-examples/python/digital/benchmark_qt_loopback2.py
@@ -223,6 +223,11 @@ class my_top_block(gr.top_block):
 
         self._noise_voltage = self.get_noise_voltage(self._snr_dB)
 
+        # With new interface, sps does not get set by default, but
+        # in the loopback, we don't recalculate it; so just force it here
+        if(options.samples_per_symbol == None):
+            options.samples_per_symbol = 2
+
         self.txpath = transmit_path(mod_class, options)
         self.throttle = gr.throttle(gr.sizeof_gr_complex, self.sample_rate())
         self.rxpath = receive_path(demod_class, rx_callback, options)
@@ -269,6 +274,7 @@ class my_top_block(gr.top_block):
                 self.phase_recov = self.rxpath.packet_receiver._demodulator.phase_recov
                 self.time_recov = self.rxpath.packet_receiver._demodulator.time_recov
                 self.freq_recov.set_alpha(self._gain_freq)
+                self.freq_recov.set_beta(self._gain_freq/10.0)
                 self.phase_recov.set_alpha(self._gain_phase)
                 self.phase_recov.set_beta(0.25*self._gain_phase*self._gain_phase)
                 self.time_recov.set_alpha(self._gain_clock)
@@ -367,6 +373,7 @@ class my_top_block(gr.top_block):
         self._gain_freq = gain_freq
         #self._gain_freq_beta = .25 * self._gain_freq * self._gain_freq
         self.rxpath.packet_receiver._demodulator.freq_recov.set_alpha(self._gain_freq)
+        self.rxpath.packet_receiver._demodulator.freq_recov.set_beta(self._gain_freq/10.0)
         #self.rxpath.packet_receiver._demodulator.freq_recov.set_beta(self._gain_fre_beta)
 
 
diff --git a/gnuradio-examples/python/digital/benchmark_qt_rx2.py b/gnuradio-examples/python/digital/benchmark_qt_rx2.py
index 3285d8e4a..4de15e480 100755
--- a/gnuradio-examples/python/digital/benchmark_qt_rx2.py
+++ b/gnuradio-examples/python/digital/benchmark_qt_rx2.py
@@ -268,7 +268,7 @@ class my_top_block(gr.top_block):
 
         (self._bitrate, self._samples_per_symbol, self._decim) = \
                         pick_rx_bitrate(options.bitrate, self._demod_class.bits_per_symbol(), \
-                                        options.samples_per_symbol, options.decim,
+                                        options.samples_per_symbol, options.decim, \
                                         adc_rate, self.u.get_decim_rates())
 
         self.u.set_decim(self._decim)