From 6f6b022977a74596c19ae1b0748010a86abdfed2 Mon Sep 17 00:00:00 2001
From: Tom Rondeau <trondeau@vt.edu>
Date: Mon, 12 Oct 2009 18:36:55 -0400
Subject: Fixing initialization of timing gains. Alpha should be < 1, and beta
should be << 1.
---
gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
(limited to 'gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py')
diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py b/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py
index c56b598fab..4541b453b3 100644
--- a/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py
+++ b/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py
@@ -39,8 +39,8 @@ _def_verbose = False
_def_log = False
_def_costas_alpha = 0.1
-_def_timing_alpha = None
-_def_timing_beta = None
+_def_timing_alpha = 0.100
+_def_timing_beta = 0.010
_def_timing_max_dev = 1.5
@@ -220,7 +220,7 @@ class dbpsk2_demod(gr.hier_block2):
self._excess_bw = excess_bw
self._costas_alpha = costas_alpha
self._timing_alpha = timing_alpha
- self._timing_beta = _def_timing_alpha
+ self._timing_beta = _def_timing_beta
self._timing_max_dev=timing_max_dev
self._gray_code = gray_code
@@ -242,12 +242,7 @@ class dbpsk2_demod(gr.hier_block2):
self._costas_beta,
fmax, fmin, arity)
- # symbol clock recovery
- if not self._timing_alpha:
- self._timing_alpha = 2
- self._timing_beta = 0.020
-
- # RRC data filter
+ # symbol timing recovery with RRC data filter
nfilts = 32
ntaps = 11 * samples_per_symbol*nfilts
taps = gr.firdes.root_raised_cosine(nfilts, nfilts, 1.0/float(self._samples_per_symbol), self._excess_bw, ntaps)
--
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