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add tone detect option 

git-svn-id: http://op25.osmocom.org/svn/trunk@299 65a5c917-d112-43f1-993d-58c26a4786be
This commit is contained in:
max 2012-05-29 15:17:27 +00:00
parent e567496a8a
commit 5640f0e1a7
1 changed files with 24 additions and 16 deletions
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40
python/cqpsk-demod-file.py
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@ -34,10 +34,11 @@ class my_top_block(gr.top_block):
parser.add_option("-g", "--gain", type="eng_float", default=1.0)
parser.add_option("-i", "--input-file", type="string", default="in.dat", help="specify the input file")
parser.add_option("-I", "--imbe", action="store_true", default=False, help="output IMBE codewords")
parser.add_option("-L", "--low-pass", type="eng_float", default=12.5e3, help="low pass cut-off", metavar="Hz")
parser.add_option("-L", "--low-pass", type="eng_float", default=6.5e3, help="low pass cut-off", metavar="Hz")
parser.add_option("-o", "--output-file", type="string", default="out.dat", help="specify the output file")
parser.add_option("-p", "--polarity", action="store_true", default=False, help="use reversed polarity")
parser.add_option("-s", "--sample-rate", type="int", default=96000, help="input sample rate")
parser.add_option("-t", "--tone-detect", action="store_true", default=False, help="use experimental tone detect algorithm")
parser.add_option("-v", "--verbose", action="store_true", default=False, help="additional output")
(options, args) = parser.parse_args()
@ -61,20 +62,27 @@ class my_top_block(gr.top_block):
lpf_taps = gr.firdes.low_pass(1.0, sample_rate, options.low_pass, options.low_pass * 0.1, gr.firdes.WIN_HANN)
# decim by 2 to get 48k rate
DECIM = gr.fir_filter_ccf (2, lpf_taps)
sample_rate /= 2 # for DECIM
samples_per_symbol /= 2 # for DECIM
# create Gardner/Costas loop
# the loop will not work if the sample levels aren't normalized (above)
timing_error_gain = 0.025 # loop error gain
gain_omega = 0.25 * timing_error_gain * timing_error_gain
alpha = options.costas_alpha
beta = 0.125 * alpha * alpha
fmin = -0.025 # fmin and fmax are in radians/s
fmax = 0.025
GARDNER_COSTAS = repeater.gardner_costas_cc(samples_per_symbol, timing_error_gain, gain_omega, alpha, beta, fmax, fmin)
decim_amt = 1
if options.tone_detect:
step_size = 7.5e-8
theta = -4 # optimum timing sampling point
cic_length = 48
DEMOD = repeater.tdetect_cc(samples_per_symbol, step_size, theta, cic_length)
else:
# decim by 2 to get 48k rate
samples_per_symbol /= 2 # for DECIM
sample_rate /= 2 # for DECIM
decim_amt = 2
# create Gardner/Costas loop
# the loop will not work if the sample levels aren't normalized (above)
timing_error_gain = 0.025 # loop error gain
gain_omega = 0.25 * timing_error_gain * timing_error_gain
alpha = options.costas_alpha
beta = 0.125 * alpha * alpha
fmin = -0.025 # fmin and fmax are in radians/s
fmax = 0.025
DEMOD = repeater.gardner_costas_cc(samples_per_symbol, timing_error_gain, gain_omega, alpha, beta, fmax, fmin)
DECIM = gr.fir_filter_ccf (decim_amt, lpf_taps)
# probably too much phase noise etc to attempt coherent demodulation
# so we use differential
@ -117,7 +125,7 @@ class my_top_block(gr.top_block):
else:
self.connect(IN, (MIXER, 0))
self.connect(LO, (MIXER, 1))
self.connect(MIXER, AMP, DECIM, GARDNER_COSTAS, DIFF, TOFLOAT, RESCALE, POLARITY, SLICER, DECODER, OUT)
self.connect(MIXER, AMP, DECIM, DEMOD, DIFF, TOFLOAT, RESCALE, POLARITY, SLICER, DECODER, OUT)
if options.debug:
print 'Ready for GDB to attach (pid = %d)' % (os.getpid(),)