On Monday 23 March 2009 16:35:45 Johnathan Corgan wrote:
> On Thu, Mar 19, 2009 at 4:18 AM, Stefan Brüns
>
> <stefan.bru...@rwth-aachen.de> wrote:
> > I mentioned some problems with carrier offsets between different USRPs
> > (or daughterboards, for RFX non-MIMO boards)
>
> We've got the patch in the queue for testing.  It looks correct,
> though I wonder how the block even worked at all given this issue.

And another one - constellation points for the mpsk receiver block are at 
2*pi/M degrees ...

Strictly speaking the second factor is not needed, but this gives slightly 
better results for me. 

Stefan

-- 
Stefan Brüns  /  Bergstraße 21  /  52062 Aachen
mailto:lurch at gmx.li  http://www.kawo1.rwth-aachen.de/~lurchi/
   phone: +49 241 53809034     mobile: +49 151 50412019
=== modified file 'gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc'
--- gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc	2008-11-23 17:10:23 +0000
+++ gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc	2009-03-27 17:47:02 +0000
@@ -123,9 +123,16 @@
 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;
+  switch(d_current_const_point) {
+  case 0:
+	return -sample.imag()*sample.real();
+  case 1:
+	return sample.real()*sample.imag();
+  case 2:
+	return sample.imag()*-sample.real();
+  default:
+	return -sample.real()*-sample.imag();
+  }
 }
 
 float
_______________________________________________
Discuss-gnuradio mailing list
Discuss-gnuradio@gnu.org
http://lists.gnu.org/mailman/listinfo/discuss-gnuradio

Reply via email to