[Commit-gnuradio] r8481 - gnuradio/branches/developers/cswiger/wip/gr-atsc/src/lib

[cswiger]

Author: cswiger
Date: 2008-05-22 10:55:59 -0600 (Thu, 22 May 2008)
New Revision: 8481

Modified:
   gnuradio/branches/developers/cswiger/wip/gr-atsc/src/lib/atsc_cpll.cc
   gnuradio/branches/developers/cswiger/wip/gr-atsc/src/lib/atsc_cpll.h
Log:
Fixed pll, complex in - real out; adjusted agc reference


Modified: gnuradio/branches/developers/cswiger/wip/gr-atsc/src/lib/atsc_cpll.cc
===================================================================
--- gnuradio/branches/developers/cswiger/wip/gr-atsc/src/lib/atsc_cpll.cc       
2008-05-22 05:15:53 UTC (rev 8480)
+++ gnuradio/branches/developers/cswiger/wip/gr-atsc/src/lib/atsc_cpll.cc       
2008-05-22 16:55:59 UTC (rev 8481)
@@ -29,8 +29,9 @@
 #include <atsc_consts.h>
 #include <algorithm>
 #include "fpll_btloop_coupling.h"
-#include <math.h>
 #include <gr_math.h>
+#include <math.h>
+#include <gr_sincos.h>
 
 #define M_TWOPI (2*M_PI)
 
@@ -48,7 +49,7 @@
  * their value also sets the level of the symbols going
  * into the equalizer and viterbi decoder.
  */
-static const float CPLL_AGC_REFERENCE = 2.5 * FPLL_BTLOOP_COUPLING_CONST;
+static const float CPLL_AGC_REFERENCE = 1.7675 * FPLL_BTLOOP_COUPLING_CONST;
 static const float CPLL_AGC_RATE = 0.25e-6;
 
 
@@ -56,8 +57,8 @@
 atsc_cpll::atsc_cpll()
   : gr_sync_block("atsc_cpll",
                  gr_make_io_signature(1, 1, sizeof(gr_complex)),
-                 gr_make_io_signature(1, 1, sizeof(gr_complex))),
-                 initial_phase(0)
+                 gr_make_io_signature(1, 1, sizeof(float))),
+                 initial_phase(0), d_phase(0), d_freq(0)
 {
   initial_freq = 0 - 3e6 + 0.31e6 + 5e3; // a_initial_freq;
   agc.set_rate (CPLL_AGC_RATE);
@@ -71,14 +72,14 @@
 {
   float Fs = 19.2e6;
 
-  float alpha = 1 - exp(-1.0 / Fs / 5e-6);
+  double alpha = 1 - exp(-1.0 / Fs / 5e-6);
 
-  afci.set_taps (alpha);
-  afcq.set_taps (alpha);
+  afc.set_taps (alpha);
 
   printf("Setting initial_freq: %f\n",initial_freq);
-  nco.set_freq (initial_freq / Fs * 2 * M_PI);
-  nco.set_phase (initial_phase);
+  // nco.set_freq (initial_freq / Fs * 2 * M_PI);
+  // nco.set_phase (initial_phase);
+  d_freq = initial_freq / Fs * 2 * M_PI;
 }
 
 float
@@ -100,48 +101,36 @@
   sample_phase = gr_fast_atan2f(sample.imag(),sample.real());
   return mod_2pi(sample_phase-ref_phase);
 }
-  
 
+
 int
 atsc_cpll::work (int noutput_items,
                       gr_vector_const_void_star &input_items,
                       gr_vector_void_star &output_items)
 {
   const gr_complex *in = (const gr_complex *) input_items[0];
-  gr_complex *out = (gr_complex *) output_items[0];
+  float *out = (float *) output_items[0];
 
   for (int k = 0; k < noutput_items; k++){
 
     float a_cos, a_sin;
 
-    gr_complex input;
-    input = agc.scale (in[k]);
+    gr_complex input = agc.scale (in[k]);
 
-    nco.step ();                // increment phase
-    nco.sincos (&a_sin, &a_cos);  // compute cos and sin
+    // nco.step ();                // increment phase
+    // nco.sincos (&a_sin, &a_cos);  // compute cos and sin
+    gr_sincosf(d_phase,&a_sin,&a_cos);
 
     gr_complex IQ = input * gr_complex(a_cos,-a_sin);
 
-    out[k] = IQ;
+    out[k] = IQ.real();
 
-    gr_complex filtered_IQ;
-    filtered_IQ.real() = afci.filter (IQ.real());
-    filtered_IQ.imag() = afcq.filter (IQ.imag());
+    gr_complex filtered_IQ = afc.filter (IQ);
 
     // phase detector
 
-    // float x = atan2 (filtered_Q, filtered_I);
-    float x = phase_detector(filtered_IQ, 0);
+    float x = phase_detector(filtered_IQ,0);
 
-    // avoid slamming filter with big transitions
-
-    static const float limit = M_PI / 2;
-
-    if (x > limit)
-      x = limit;
-    else if (x < -limit)
-      x = -limit;
-
     // static const float alpha = 0.037;   // Max value
     // static const float alpha = 0.005;   // takes about 5k samples to pull 
in, stddev = 323
     // static const float alpha = 0.002;   // takes about 15k samples to pull 
in, stddev =  69
@@ -149,8 +138,10 @@
     static const float alpha = 0.001;
     static const float beta = alpha * alpha / 4;
 
-    nco.adjust_phase (alpha * x);
-    nco.adjust_freq (beta * x);
+    // nco.adjust_phase (alpha * x);
+    // nco.adjust_freq (beta * x);
+    d_freq = d_freq + beta * x;
+    d_phase = mod_2pi(d_phase + d_freq + alpha * x);
 
   }
 

Modified: gnuradio/branches/developers/cswiger/wip/gr-atsc/src/lib/atsc_cpll.h
===================================================================
--- gnuradio/branches/developers/cswiger/wip/gr-atsc/src/lib/atsc_cpll.h        
2008-05-22 05:15:53 UTC (rev 8480)
+++ gnuradio/branches/developers/cswiger/wip/gr-atsc/src/lib/atsc_cpll.h        
2008-05-22 16:55:59 UTC (rev 8481)
@@ -23,7 +23,7 @@
 #define INCLUDED_ATSC_CPLL_H
 
 #include <gr_sync_block.h>
-#include <gr_nco.h>
+// #include <gr_nco.h>
 #include <gr_single_pole_iir.h>
 #include <gri_agc_cc.h>
 #include <stdio.h>
@@ -63,16 +63,16 @@
 
  protected:
 
+  float                                d_freq,d_phase;
   double                        initial_freq;
   double                        initial_phase;
   bool                          debug_no_update;
-  gr_nco<float,float>           nco;
+  // gr_nco<float,float>           nco;
   gri_agc_cc                    agc;    // automatic gain control
-  gr_single_pole_iir<float,float,float> afci;
-  gr_single_pole_iir<float,float,float> afcq;
+  gr_single_pole_iir<gr_complex,gr_complex,double> afc;
 
   float mod_2pi (float in);
-  float phase_detector(gr_complex sample, float ref_phase);
+  float phase_detector(gr_complex sample,float ref_phase);
 
 
 };