From 679ffc25379058f75642a66783f9f0688962feb1 Mon Sep 17 00:00:00 2001
From: jcorgan
Date: Sun, 21 Jun 2009 16:06:01 +0000
Subject: Fix QPSK phase error detector.  Applied patch from Ben Green,
 modified by Tom Rondeau.

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@11254 221aa14e-8319-0410-a670-987f0aec2ac5
---
 gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

(limited to 'gnuradio-core/src/lib/general')

diff --git a/gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc b/gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc
index cdb5bdc0e..49bbb8d36 100644
--- a/gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc
+++ b/gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc
@@ -123,9 +123,21 @@ gr_mpsk_receiver_cc::forecast(int noutput_items, gr_vector_int &ninput_items_req
 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());
-  return -phase_error;
+  float phase_error = 0;
+  if(fabsf(sample.real()) > fabsf(sample.imag())) {
+    if(sample.real() > 0)
+      phase_error = -sample.imag();
+    else
+      phase_error = sample.imag();
+  }
+  else {
+    if(sample.imag() > 0)
+      phase_error = sample.real();
+    else
+      phase_error = -sample.real();
+  }
+  
+  return phase_error;
 }
 
 float
-- 
cgit