[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Commit-gnuradio] r4009 - gnuradio/trunk/gnuradio-core/src/python/gnurad
From: |
trondeau |
Subject: |
[Commit-gnuradio] r4009 - gnuradio/trunk/gnuradio-core/src/python/gnuradio/blksimpl |
Date: |
Tue, 21 Nov 2006 10:21:16 -0700 (MST) |
Author: trondeau
Date: 2006-11-21 10:21:15 -0700 (Tue, 21 Nov 2006)
New Revision: 4009
Modified:
gnuradio/trunk/gnuradio-core/src/python/gnuradio/blksimpl/dqpsk.py
Log:
improved Costas loop gains for QPSK receiver
Modified: gnuradio/trunk/gnuradio-core/src/python/gnuradio/blksimpl/dqpsk.py
===================================================================
--- gnuradio/trunk/gnuradio-core/src/python/gnuradio/blksimpl/dqpsk.py
2006-11-20 18:42:54 UTC (rev 4008)
+++ gnuradio/trunk/gnuradio-core/src/python/gnuradio/blksimpl/dqpsk.py
2006-11-21 17:21:15 UTC (rev 4009)
@@ -239,13 +239,13 @@
# Costas loop (carrier tracking)
if self._costas_alpha is None: # If no alpha value was specified by
the user
- alpha_dir = {2:0.075, 3:0.075, 4:0.105, 5:0.105, 6:0.125, 7:0.130}
+ alpha_dir = {2:0.075, 3:0.09, 4:0.09, 5:0.095, 6:0.10, 7:0.105}
self._costas_alpha = alpha_dir[self._samples_per_symbol]
costas_order = 4
- # The value of beta is now set to be overdamped; this value can have a
huge impact on the
+ # The value of beta is now set to be underdamped; this value can have
a huge impact on the
# performance of QPSK. Set to 0.25 for critically damped or higher for
underdamped responses.
- beta = .15 * self._costas_alpha * self._costas_alpha
+ beta = .5 0 * self._costas_alpha * self._costas_alpha
self.costas_loop = gr.costas_loop_cc(self._costas_alpha, beta, 0.02,
-0.02, costas_order)
# RRC data filter
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- [Commit-gnuradio] r4009 - gnuradio/trunk/gnuradio-core/src/python/gnuradio/blksimpl,
trondeau <=