[Commit-gnuradio] r10040 - in gnuradio/trunk/gnuradio-core/src: lib/general python/gnuradio/blks2impl

[trondeau]

Author: trondeau
Date: 2008-11-23 10:10:23 -0700 (Sun, 23 Nov 2008)
New Revision: 10040

Modified:
   gnuradio/trunk/gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc
   gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk.py
Log:
fixing sync routines by wrapping the angle and not clipping it; also opening up 
the frequency sync range a bit.

Modified: gnuradio/trunk/gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc
===================================================================
--- gnuradio/trunk/gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc 
2008-11-23 16:38:54 UTC (rev 10039)
+++ gnuradio/trunk/gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc 
2008-11-23 17:10:23 UTC (rev 10040)
@@ -90,12 +90,12 @@
   // Select a phase detector and a decision maker for the modulation order
   switch(d_M) {
   case 2:  // optimized algorithms for BPSK
-    d_phase_error_detector = 
&gr_mpsk_receiver_cc::phase_error_detector_generic; //bpsk;
+    d_phase_error_detector = &gr_mpsk_receiver_cc::phase_error_detector_bpsk; 
//bpsk;
     d_decision = &gr_mpsk_receiver_cc::decision_bpsk;
     break;
 
   case 4: // optimized algorithms for QPSK
-    d_phase_error_detector = 
&gr_mpsk_receiver_cc::phase_error_detector_generic; //qpsk;
+    d_phase_error_detector = &gr_mpsk_receiver_cc::phase_error_detector_qpsk; 
//qpsk;
     d_decision = &gr_mpsk_receiver_cc::decision_qpsk;
     break;
 
@@ -104,8 +104,6 @@
     d_decision = &gr_mpsk_receiver_cc::decision_generic;
     break;
   }
-
-  set_history(3);                      // ensure 2 extra input sample is 
available
 }
 
 gr_mpsk_receiver_cc::~gr_mpsk_receiver_cc ()
@@ -119,24 +117,21 @@
   unsigned ninputs = ninput_items_required.size();
   for (unsigned i=0; i < ninputs; i++)
     ninput_items_required[i] = (int) ceil((noutput_items * d_omega) + 
d_interp->ntaps());
-  //ninput_items_required[i] = (int)(d_omega);
-
 }
 
 // FIXME add these back in an test difference in performance
 float
 gr_mpsk_receiver_cc::phase_error_detector_qpsk(gr_complex sample) const
 {
-  float phase_error = ((sample.real()>0 ? 1.0 : -1.0) * sample.imag() -
-                      (sample.imag()>0 ? 1.0 : -1.0) * sample.real());
+  float phase_error = -((sample.real()>0 ? 1.0 : -1.0) * sample.imag() -
+                       (sample.imag()>0 ? 1.0 : -1.0) * sample.real());
   return -phase_error;
 }
 
-// FIXME add these back in an test difference in performance
 float
 gr_mpsk_receiver_cc::phase_error_detector_bpsk(gr_complex sample) const
 {
-  return (sample.real()*sample.imag());
+  return -(sample.real()*sample.imag());
 }
 
 float gr_mpsk_receiver_cc::phase_error_detector_generic(gr_complex sample) 
const
@@ -200,7 +195,10 @@
   d_phase += d_freq;  // increment the phase based on the frequency of the 
rotation
 
   // Keep phase clamped and not walk to infinity
-  d_phase = gr_branchless_clip(d_phase, M_TWOPI);
+  while(d_phase > M_TWOPI)
+    d_phase -= M_TWOPI;
+  while(d_phase < -M_TWOPI)
+    d_phase += M_TWOPI;
   
   nco = gr_expj(d_phase+d_theta);   // get the NCO value for derotating the 
current sample
   sample = nco*symbol;      // get the downconverted symbol
@@ -262,7 +260,10 @@
   d_phase += d_freq + d_alpha*phase_error;  // adjust phase based on error
 
   // Make sure we stay within +-2pi
-  d_phase = gr_branchless_clip(d_phase, M_TWOPI);
+  while(d_phase > M_TWOPI)
+    d_phase -= M_TWOPI;
+  while(d_phase < -M_TWOPI)
+    d_phase += M_TWOPI;
   
   // Limit the frequency range
   d_freq = gr_branchless_clip(d_freq, d_max_freq);

Modified: gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk.py
===================================================================
--- gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk.py 
2008-11-23 16:38:54 UTC (rev 10039)
+++ gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk.py 
2008-11-23 17:10:23 UTC (rev 10040)
@@ -255,8 +255,8 @@
         self._mm_omega = self._samples_per_symbol
         self._mm_gain_omega = .25 * self._mm_gain_mu * self._mm_gain_mu
         self._costas_beta  = 0.25 * self._costas_alpha * self._costas_alpha
-        fmin = -0.025
-        fmax = 0.025
+        fmin = -0.1
+        fmax = 0.1
         
         self.receiver=gr.mpsk_receiver_cc(arity, 0,
                                          self._costas_alpha, self._costas_beta,