From 5c071b07710d2c4e127d321faba59b2a7b1d7c8d Mon Sep 17 00:00:00 2001
From: jcorgan <jcorgan@221aa14e-8319-0410-a670-987f0aec2ac5>
Date: Sun, 14 Sep 2008 18:37:08 +0000
Subject: Adds frequency accessor for Costas loop, BERT receiver displays
frequency and timing offset
git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@9576 221aa14e-8319-0410-a670-987f0aec2ac5
---
.../python/digital-bert/receive_path.py | 32 ++++++++++++----------
1 file changed, 17 insertions(+), 15 deletions(-)
(limited to 'gnuradio-examples/python/digital-bert/receive_path.py')
diff --git a/gnuradio-examples/python/digital-bert/receive_path.py b/gnuradio-examples/python/digital-bert/receive_path.py
index 84ff329165..e273923a4f 100644
--- a/gnuradio-examples/python/digital-bert/receive_path.py
+++ b/gnuradio-examples/python/digital-bert/receive_path.py
@@ -41,21 +41,22 @@ class receive_path(gr.hier_block2):
gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
gr.io_signature(0, 0, 0)) # Output signature
- sps = int(if_rate/symbol_rate)
- print "IF sample rate:", n2s(if_rate)
+ self._if_rate = if_rate
+ self._sps = int(self._if_rate/symbol_rate)
+ print "IF sample rate:", n2s(self._if_rate)
print "Symbol rate:", n2s(symbol_rate)
- print "Samples/symbol:", sps
+ print "Samples/symbol:", self._sps
print "RRC bandwidth:", excess_bw
# Create AGC to scale input to unity
self._agc = gr.agc_cc(1e-5, 1.0, 1.0, 1.0)
# Create RRC with specified excess bandwidth
- taps = gr.firdes.root_raised_cosine(1.0, # Gain
- sps, # Sampling rate
- 1.0, # Symbol rate
- excess_bw, # Roll-off factor
- 11*sps) # Number of taps
+ taps = gr.firdes.root_raised_cosine(1.0, # Gain
+ self._sps, # Sampling rate
+ 1.0, # Symbol rate
+ excess_bw, # Roll-off factor
+ 11*self._sps) # Number of taps
self._rrc = gr.fir_filter_ccf(1, taps)
@@ -73,7 +74,7 @@ class receive_path(gr.hier_block2):
# Create a M&M bit synchronization retiming block
mm_mu = 0.5
- mm_omega = sps
+ mm_omega = self._sps
print "MM gain mu:", mm_gain_mu
print "MM gain omega:", mm_gain_omega
@@ -103,14 +104,15 @@ class receive_path(gr.hier_block2):
self.connect(self, self._agc, self._rrc, self._costas, self._mm,
self._c2r, self._slicer, self._descrambler, self._ber)
+ def frequency_offset(self):
+ return self._costas.freq()*self._if_rate/(2*math.pi)
+
+ def timing_offset(self):
+ return self._mm.omega()/self._sps-1.0
+
def snr(self):
return self._snr_probe.snr()
- def signal_mean(self):
- return self._snr_probe.signal_mean()
-
- def noise_variance(self):
- return self._snr_probe.noise_variance()
-
def ber(self):
return (1.0-self._ber.density())/3.0
+
--
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