From: jcorgan <jcorgan@221aa14e-8319-0410-a670-987f0aec2ac5>
Date: Sun, 21 Jun 2009 16:06:01 +0000 (+0000)
Subject: Fix QPSK phase error detector.  Applied patch from Ben Green, modified by Tom Rondeau.
X-Git-Url: https://git.gag.com/?a=commitdiff_plain;h=679ffc25379058f75642a66783f9f0688962feb1;hp=9c177f4194a3ed52ba6e94c66851a0f635c61fd5;p=debian%2Fgnuradio

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
---

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 cdb5bdc0..49bbb8d3 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