From eeea619b80578665fd470f850c390d4aa6782336 Mon Sep 17 00:00:00 2001
From: Tom <trondeau@vt.edu>
Date: Wed, 7 Oct 2009 17:45:19 -0700
Subject: [PATCH] More stable version of clock sync.

---
 .../src/lib/filter/gr_pfb_clock_sync_ccf.cc        | 14 +++++++++-----
 .../src/lib/filter/gr_pfb_clock_sync_ccf.h         |  3 ++-
 2 files changed, 11 insertions(+), 6 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 35fe2a88..fe399ffb 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
@@ -63,6 +63,7 @@ gr_pfb_clock_sync_ccf::gr_pfb_clock_sync_ccf (float sps, float gain,
   set_alpha(gain);
   set_beta(0.25*gain*gain);
   d_k = d_nfilters / 2;
+  d_filtnum = (int)floor(d_k);
   d_rate = 0;
   d_start_count = 0;
   
@@ -237,21 +238,24 @@ 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();
+    out[i] = d_filters[d_filtnum]->filter(&in[count]);
+    error =  (out[i] * d_diff_filters[d_filtnum]->filter(&in[count])).real();
 
     d_k = d_k + d_alpha*error + d_rate;
     d_rate = d_rate + d_beta*error;
-    while(d_k >= (float)d_nfilters) {
+    d_filtnum = (int)floor(d_k);
+
+    while(d_filtnum >= d_nfilters) {
       d_k -= d_nfilters;
+      d_filtnum -= d_nfilters;
       count++;
     }
-    while(d_k < 0) {
+    while(d_filtnum < 0) {
       d_k += d_nfilters;
+      d_filtnum += d_nfilters;
       count--;
     }
     
diff --git a/gnuradio-core/src/lib/filter/gr_pfb_clock_sync_ccf.h b/gnuradio-core/src/lib/filter/gr_pfb_clock_sync_ccf.h
index 14e95869..41e5d7b2 100644
--- a/gnuradio-core/src/lib/filter/gr_pfb_clock_sync_ccf.h
+++ b/gnuradio-core/src/lib/filter/gr_pfb_clock_sync_ccf.h
@@ -59,13 +59,14 @@ class gr_pfb_clock_sync_ccf : public gr_block
   unsigned int             d_sps;
   float                    d_alpha;
   float                    d_beta;
-  unsigned int             d_nfilters;
+  int                      d_nfilters;
   std::vector<gr_fir_ccf*> d_filters;
   std::vector<gr_fir_ccf*> d_diff_filters;
   std::vector< std::vector<float> > d_taps;
   std::vector< std::vector<float> > d_dtaps;
   float                    d_k;
   float                    d_rate;
+  int                      d_filtnum;
   unsigned int             d_start_count;
   unsigned int             d_taps_per_filter;
 
-- 
2.30.2