Clipping the rate of the clock recovery helps track large changes.

2 files changed, 91 insertions, 79 deletions

diff --git a/gnuradio-core/src/lib/filter/gr_pfb_clock_sync_ccf.cc b/gnuradio-core/src/lib/filter/gr_pfb_clock_sync_ccf.cc
index 62282fd6a..35fe2a886 100644
--- a/gnuradio-core/src/lib/filter/gr_pfb_clock_sync_ccf.cc
+++ b/gnuradio-core/src/lib/filter/gr_pfb_clock_sync_ccf.cc
@@ -115,13 +115,15 @@ gr_pfb_clock_sync_ccf::set_taps (const std::vector<float> &newtaps,
   // Partition the filter
   for(i = 0; i < d_nfilters; i++) {
     // Each channel uses all d_taps_per_filter with 0's if not enough taps to fill out
-    ourtaps[i] = std::vector<float>(d_taps_per_filter, 0);
+    //ourtaps[i] = std::vector<float>(d_taps_per_filter, 0);
+    ourtaps[d_nfilters-1-i] = std::vector<float>(d_taps_per_filter, 0);
     for(j = 0; j < d_taps_per_filter; j++) {
-      ourtaps[i][j] = tmp_taps[i + j*d_nfilters];  // add taps to channels in reverse order
+      ourtaps[d_nfilters - 1 - i][j] = tmp_taps[i + j*d_nfilters];
     }
     
     // Build a filter for each channel and add it's taps to it
-    ourfilter[i]->set_taps(ourtaps[i]);
+    //ourfilter[i]->set_taps(ourtaps[i]);
+    ourfilter[i]->set_taps(ourtaps[d_nfilters-1-i]);
   }
 
   // Set the history to ensure enough input items for each filter
@@ -156,26 +158,30 @@ void
 gr_pfb_clock_sync_ccf::print_taps()
 {
   unsigned int i, j;
+  printf("[ ");
   for(i = 0; i < d_nfilters; i++) {
-    printf("filter[%d]: [%.4e, ", i, d_taps[i][0]);
+    printf("[%.4e, ", d_taps[i][0]);
     for(j = 1; j < d_taps_per_filter-1; j++) {
       printf("%.4e,", d_taps[i][j]);
     }
-    printf("%.4e]\n", d_taps[i][j]);
+    printf("%.4e],", d_taps[i][j]);
   }
+  printf(" ]\n");
 }
 
 void
 gr_pfb_clock_sync_ccf::print_diff_taps()
 {
   unsigned int i, j;
+  printf("[ ");
   for(i = 0; i < d_nfilters; i++) {
-    printf("filter[%d]: [%.4e, ", i, d_dtaps[i][0]);
+    printf("[%.4e, ", d_dtaps[i][0]);
     for(j = 1; j < d_taps_per_filter-1; j++) {
       printf("%.4e,", d_dtaps[i][j]);
     }
-    printf("%.4e]\n", d_dtaps[i][j]);
+    printf("%.4e],", d_dtaps[i][j]);
   }
+  printf(" ]\n");
 }
 
 
@@ -232,12 +238,15 @@ gr_pfb_clock_sync_ccf::general_work (int noutput_items,
   // produce output as long as we can and there are enough input samples
   while((i < noutput_items) && (count < nrequired)) {
     int filtnum = (int)d_k;
+
+    // FIXME: prevent this from asserting
+    assert(filtnum < d_nfilters);
     out[i] = d_filters[filtnum]->filter(&in[count]);
     error =  (out[i] * d_diff_filters[filtnum]->filter(&in[count])).real();
 
     d_k = d_k + d_alpha*error + d_rate;
     d_rate = d_rate + d_beta*error;
-    while(d_k >= d_nfilters) {
+    while(d_k >= (float)d_nfilters) {
       d_k -= d_nfilters;
       count++;
     }
@@ -245,6 +254,9 @@ gr_pfb_clock_sync_ccf::general_work (int noutput_items,
       d_k += d_nfilters;
       count--;
     }
+    
+    // Keep our rate within a good range
+    d_rate = gr_branchless_clip(d_rate, 1.5);
 
     i++;
     count += d_sps;
diff --git a/gnuradio-examples/grc/demod/pam_timing.grc b/gnuradio-examples/grc/demod/pam_timing.grc
index ab34677fa..21fb63abe 100644
--- a/gnuradio-examples/grc/demod/pam_timing.grc
+++ b/gnuradio-examples/grc/demod/pam_timing.grc
@@ -1,6 +1,6 @@
 <?xml version='1.0' encoding='ASCII'?>
 <flow_graph>
-  <timestamp>Tue Oct  6 22:05:15 2009</timestamp>
+  <timestamp>Wed Oct  7 11:00:26 2009</timestamp>
   <block>
     <key>options</key>
     <param>
@@ -820,54 +820,42 @@
     </param>
   </block>
   <block>
-    <key>variable_slider</key>
+    <key>gr_pfb_clock_sync_ccf</key>
     <param>
       <key>id</key>
-      <value>alpha</value>
+      <value>gr_pfb_clock_sync_ccf_0</value>
     </param>
     <param>
       <key>_enabled</key>
       <value>True</value>
     </param>
     <param>
-      <key>label</key>
-      <value>Alpha</value>
-    </param>
-    <param>
-      <key>value</key>
-      <value>0</value>
-    </param>
-    <param>
-      <key>min</key>
-      <value>0</value>
-    </param>
-    <param>
-      <key>max</key>
-      <value>1</value>
+      <key>sps</key>
+      <value>spb</value>
     </param>
     <param>
-      <key>num_steps</key>
-      <value>1000</value>
+      <key>alpha</key>
+      <value>alpha</value>
     </param>
     <param>
-      <key>style</key>
-      <value>wx.SL_HORIZONTAL</value>
+      <key>beta</key>
+      <value>beta</value>
     </param>
     <param>
-      <key>converver</key>
-      <value>float_converter</value>
+      <key>taps</key>
+      <value>rrctaps</value>
     </param>
     <param>
-      <key>grid_pos</key>
-      <value></value>
+      <key>filter_size</key>
+      <value>nfilts</value>
     </param>
     <param>
-      <key>notebook</key>
-      <value></value>
+      <key>init_phase</key>
+      <value>14</value>
     </param>
     <param>
       <key>_coordinate</key>
-      <value>(757, -1)</value>
+      <value>(346, 773)</value>
     </param>
     <param>
       <key>_rotation</key>
@@ -875,42 +863,22 @@
     </param>
   </block>
   <block>
-    <key>gr_pfb_clock_sync_ccf</key>
+    <key>variable</key>
     <param>
       <key>id</key>
-      <value>gr_pfb_clock_sync_ccf_0</value>
+      <value>rrctaps</value>
     </param>
     <param>
       <key>_enabled</key>
       <value>True</value>
     </param>
     <param>
-      <key>sps</key>
-      <value>spb</value>
-    </param>
-    <param>
-      <key>alpha</key>
-      <value>alpha</value>
-    </param>
-    <param>
-      <key>beta</key>
-      <value>beta</value>
-    </param>
-    <param>
-      <key>taps</key>
-      <value>rrctaps</value>
-    </param>
-    <param>
-      <key>filter_size</key>
-      <value>nfilts</value>
-    </param>
-    <param>
-      <key>init_phase</key>
-      <value>14</value>
+      <key>value</key>
+      <value>firdes.root_raised_cosine(nfilts,1.0,1.0/(spb*nfilts), .35, 11*spb*nfilts)</value>
     </param>
     <param>
       <key>_coordinate</key>
-      <value>(346, 773)</value>
+      <value>(110, 830)</value>
     </param>
     <param>
       <key>_rotation</key>
@@ -921,7 +889,7 @@
     <key>variable_slider</key>
     <param>
       <key>id</key>
-      <value>interpratio</value>
+      <value>beta</value>
     </param>
     <param>
       <key>_enabled</key>
@@ -929,19 +897,19 @@
     </param>
     <param>
       <key>label</key>
-      <value></value>
+      <value>Beta</value>
     </param>
     <param>
       <key>value</key>
-      <value>1</value>
+      <value>10e-3</value>
     </param>
     <param>
       <key>min</key>
-      <value>0</value>
+      <value>0.0</value>
     </param>
     <param>
       <key>max</key>
-      <value>2</value>
+      <value>0.1</value>
     </param>
     <param>
       <key>num_steps</key>
@@ -965,30 +933,62 @@
     </param>
     <param>
       <key>_coordinate</key>
-      <value>(232, 921)</value>
+      <value>(871, 0)</value>
     </param>
     <param>
       <key>_rotation</key>
-      <value>180</value>
+      <value>0</value>
     </param>
   </block>
   <block>
-    <key>variable</key>
+    <key>variable_slider</key>
     <param>
       <key>id</key>
-      <value>rrctaps</value>
+      <value>alpha</value>
     </param>
     <param>
       <key>_enabled</key>
       <value>True</value>
     </param>
     <param>
+      <key>label</key>
+      <value>Alpha</value>
+    </param>
+    <param>
       <key>value</key>
-      <value>firdes.root_raised_cosine(nfilts,1.0,1.0/(spb*nfilts), .35, 11*spb*nfilts)</value>
+      <value>2</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>10</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>(110, 830)</value>
+      <value>(757, -1)</value>
     </param>
     <param>
       <key>_rotation</key>
@@ -999,7 +999,7 @@
     <key>variable_slider</key>
     <param>
       <key>id</key>
-      <value>beta</value>
+      <value>interpratio</value>
     </param>
     <param>
       <key>_enabled</key>
@@ -1007,19 +1007,19 @@
     </param>
     <param>
       <key>label</key>
-      <value>Beta</value>
+      <value></value>
     </param>
     <param>
       <key>value</key>
-      <value>0</value>
+      <value>1.001</value>
     </param>
     <param>
       <key>min</key>
-      <value>0.0</value>
+      <value>0</value>
     </param>
     <param>
       <key>max</key>
-      <value>0.1</value>
+      <value>2</value>
     </param>
     <param>
       <key>num_steps</key>
@@ -1043,11 +1043,11 @@
     </param>
     <param>
       <key>_coordinate</key>
-      <value>(871, 0)</value>
+      <value>(757, 133)</value>
     </param>
     <param>
       <key>_rotation</key>
-      <value>0</value>
+      <value>180</value>
     </param>
   </block>
   <connection>