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#!/usr/bin/env python2
# -*- coding: utf8 -*-
# Andreas Müller, 2008
# andrmuel@ee.ethz.ch
#
# this code may be freely used under GNU GPL conditions
"""
receive DAB with USRP
"""
from gnuradio import gr, uhd, blocks
import gnuradio.dab as grdab
from gnuradio.eng_option import eng_option
from optparse import OptionParser
import sys, time, threading, math
class usrp_dab_rx(gr.top_block):
def __init__(self):
gr.top_block.__init__(self)
parser = OptionParser(option_class=eng_option, usage="%prog: [options] output-filename")
parser.add_option("-m", "--dab-mode", type="int", default=1,
help="DAB mode [default=%default]")
parser.add_option("-F", "--filter-input", action="store_true", default=False,
help="Enable FFT filter at input")
parser.add_option('-c', '--correct-ffe', action="store_true", default=False,
help="do fine frequency correction")
parser.add_option('-u', '--correct-ffe-usrp', action="store_true", default=False,
help="do fine frequency correction by retuning the USRP instead of in software")
parser.add_option('-e', '--equalize-magnitude', action="store_true", default=False,
help="do magnitude equalization")
parser.add_option("-s", "--resample-fixed", type="eng_float", default=1,
help="resample by a fixed factor (fractional interpolation)")
parser.add_option("-S", "--autocorrect-sample-rate", action="store_true", default=False,
help="Estimate sample rate offset and resample (dynamic fractional interpolation)")
parser.add_option("-R", "--rx-subdev-spec", type="subdev", default=(0, 0),
help="select USRP Rx side A or B [default=A]")
parser.add_option("-f", "--freq", type="eng_float", default=227.36e6,
help="set frequency to FREQ [default=%default]")
parser.add_option("-d", "--decim", type="intx", default=32,
help="set decimation rate to DECIM [default=%default]")
parser.add_option("-g", "--rx-gain", type="eng_float", default=None,
help="set receive gain in dB (default is midpoint)")
parser.add_option('-v', '--verbose', action="store_true", default=False,
help="verbose output")
parser.add_option('-a', '--antenna', type="string", default="TX/RX",
help="select antenna")
(options, args) = parser.parse_args ()
# if len(args)!=1:
# parser.print_help()
# sys.exit(1)
# else:
# self.filename = args[0]
# if gr.enable_realtime_scheduling() != gr.RT_OK:
# print "-> failed to enable realtime scheduling"
self.verbose = options.verbose
self.src = uhd.usrp_source("",uhd.io_type.COMPLEX_FLOAT32,1)
#self.src.set_mux(usrp.determine_rx_mux_value(self.src, options.rx_subdev_spec))
#self.subdev = uhd.selected_subdev(self.src, options.rx_subdev_spec)
#print "--> using RX dboard " + self.subdev.side_and_name()
self.sample_rate = 2e6#self.src.adc_rate()/options.decim
self.src.set_samp_rate(self.sample_rate)
self.src.set_antenna(options.antenna)
self.dab_params = grdab.parameters.dab_parameters(mode=options.dab_mode, sample_rate=self.sample_rate, verbose=options.verbose)
self.rx_params = grdab.parameters.receiver_parameters(mode=options.dab_mode, softbits=True, input_fft_filter=options.filter_input, autocorrect_sample_rate=options.autocorrect_sample_rate, sample_rate_correction_factor=options.resample_fixed, verbose=options.verbose, correct_ffe=options.correct_ffe, equalize_magnitude=options.equalize_magnitude)
self.demod = grdab.ofdm_demod(self.dab_params, self.rx_params, verbose=options.verbose)
# self.sink = gr.file_sink(gr.sizeof_char*384, self.filename)
# self.trigsink = gr.null_sink(gr.sizeof_char)
# self.connect(self.src, self.demod, self.sink)
# self.connect((self.demod,1), self.trigsink)
self.fic_dec = grdab.fic_decode(self.dab_params)
self.connect(self.src, self.demod, (self.fic_dec,0))
self.connect((self.demod,1), (self.fic_dec,1))
# tune frequency
self.frequency = options.freq
self.set_freq(options.freq)
# set gain
if options.rx_gain is None:
# if no gain was specified, use the mid-point in dB
g = self.src.get_gain_range()
options.rx_gain = float(g.start()+g.stop())/2
self.src.set_gain(options.rx_gain)
#self.subdev.set_gain(options.rx_gain)
self.update_ui = options.verbose
if self.update_ui:
self.run_ui_update_thread = True
self.ui_updater = threading.Timer(0.1,self.update_ui_function)
self.ui_updater.setDaemon(True)
self.ui_updater.start()
self.correct_ffe_usrp = options.correct_ffe_usrp
if self.correct_ffe_usrp:
print "--> correcting FFE on USRP"
self.run_correct_ffe_thread = True
self.ffe_updater = threading.Timer(0.1, self.correct_ffe)
self.ffe_updater.setDaemon(True)
self.ffe_updater.start()
def update_ui_function(self):
while self.run_ui_update_thread:
var = self.demod.probe_phase_var.level()
q = int(50*(math.sqrt(var)/(math.pi/4)))
print "--> Phase variance: " + str(var) +"\n"
print "--> Signal quality: " + '='*(50-q) + '>' + '-'*q + "\n"
time.sleep(0.3)
def correct_ffe(self):
while self.run_correct_ffe_thread:
diff = self.demod.sync.ffs_sample_and_average_arg.ffe_estimate()
if abs(diff) > self.rx_params.usrp_ffc_min_deviation:
self.frequency -= diff*self.rx_params.usrp_ffc_adapt_factor
print "--> updating fine frequency correction: " + str(self.frequency)
self.set_freq(self.frequency)
time.sleep(1./self.rx_params.usrp_ffc_retune_frequency)
def set_freq(self, freq):
if self.src.set_center_freq(freq): #src.tune(0, self.subdev, freq):
if self.verbose:
print "--> retuned to " + str(freq) + " Hz"
return True
else:
print "-> error - cannot tune to " + str(freq) + " Hz"
return False
if __name__=='__main__':
try:
rx = usrp_dab_rx()
rx.run()
except KeyboardInterrupt:
pass
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