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authorPiotr Krysik <perper@o2.pl>2009-04-20 19:49:01 +0200
committerPiotr Krysik <perper@o2.pl>2009-04-20 19:49:01 +0200
commit00cf03a40f5ddee09aadec5a45d6bb311d170bbd (patch)
tree17eb60da8786d0ef7ef80ccee45aec8246b2c6f4 /src/python/gsm_findfcch_usrp.py
parent04c193d15192d926c7349ca4a9362d721fe0db6c (diff)
Corrected precision of FCCH search function
Diffstat (limited to 'src/python/gsm_findfcch_usrp.py')
-rwxr-xr-xsrc/python/gsm_findfcch_usrp.py122
1 files changed, 122 insertions, 0 deletions
diff --git a/src/python/gsm_findfcch_usrp.py b/src/python/gsm_findfcch_usrp.py
new file mode 100755
index 0000000..7bf81f3
--- /dev/null
+++ b/src/python/gsm_findfcch_usrp.py
@@ -0,0 +1,122 @@
+#!/usr/bin/env python
+#!/usr/bin/env python
+
+from gnuradio import gr, gru, blks2
+from gnuradio import usrp
+#from gnuradio import gsm
+from gnuradio.eng_option import eng_option
+from optparse import OptionParser
+from os import sys
+#"""
+for extdir in ['../../debug/src/lib','../../debug/src/lib/.libs']:
+ if extdir not in sys.path:
+ sys.path.append(extdir)
+import gsm
+#"""
+def pick_subdevice(u):
+ if u.db[0][0].dbid() >= 0:
+ return (0, 0)
+ if u.db[1][0].dbid() >= 0:
+ return (1, 0)
+ return (0, 0)
+
+class gsm_receiver_first_blood(gr.top_block):
+ def __init__(self):
+ gr.top_block.__init__(self)
+ ( self.options, self.args) = self._przetworz_opcje()
+ self._ustaw_taktowanie()
+ self.zrodlo = self._ustaw_zrodlo()
+ self.filtr = self._ustaw_filtr()
+ self.interpolator = self._ustaw_interpolator()
+ self.odbiornik = self._ustaw_odbiornik()
+ self.konwerter = self._ustaw_konwerter()
+ self.ujscie = self._ustaw_ujscie()
+
+ self.connect(self.zrodlo, self.filtr, self.interpolator, self.odbiornik, self.konwerter, self.ujscie)
+# self.connect(self.zrodlo, self.ujscie)
+
+ def _ustaw_ujscie(self):
+ nazwa_pliku_wy = self.options.outputfile
+ ujscie = gr.file_sink(gr.sizeof_float, nazwa_pliku_wy)
+ return ujscie
+
+ def _ustaw_zrodlo(self):
+ options = self.options
+ fusb_block_size = gr.prefs().get_long('fusb', 'block_size', 4096)
+ fusb_nblocks = gr.prefs().get_long('fusb', 'nblocks', 16)
+ self.usrp = usrp.source_c(decim_rate=options.decim, fusb_block_size=fusb_block_size, fusb_nblocks=fusb_nblocks)
+
+ if options.rx_subdev_spec is None:
+ options.rx_subdev_spec = pick_subdevice(self.usrp)
+
+ self.usrp.set_mux(usrp.determine_rx_mux_value(self.usrp, options.rx_subdev_spec))
+ # determine the daughterboard subdevice
+ self.subdev = usrp.selected_subdev(self.usrp, options.rx_subdev_spec)
+ input_rate = self.usrp.adc_freq() / self.usrp.decim_rate()
+
+ # set initial values
+ if options.gain is None:
+ # if no gain was specified, use the mid-point in dB
+ g = self.subdev.gain_range()
+ options.gain = float(g[0]+g[1])/2
+
+ r = self.usrp.tune(0, self.subdev, options.freq)
+ self.subdev.set_gain(options.gain)
+ return self.usrp
+
+ def _ustaw_taktowanie(self):
+ options = self.options
+ clock_rate = 64e6
+ self.clock_rate = clock_rate
+ self.input_rate = clock_rate / options.decim
+ self.gsm_symb_rate = 1625000.0 / 6.0
+ self.sps = self.input_rate / self.gsm_symb_rate
+
+ def _ustaw_filtr(self):
+ filter_cutoff = 145e3
+ filter_t_width = 10e3
+ offset = 0
+ print "input_rate:", self.input_rate, "sample rate:", self.sps, " filter_cutoff:", filter_cutoff, " filter_t_width:", filter_t_width
+ filter_taps = gr.firdes.low_pass(1.0, self.input_rate, filter_cutoff, filter_t_width, gr.firdes.WIN_HAMMING)
+ filtr = gr.freq_xlating_fir_filter_ccf(1, filter_taps, offset, self.input_rate)
+ return filtr
+
+ def _ustaw_konwerter(self):
+ v2s = gr.vector_to_stream(gr.sizeof_float, 142)
+ return v2s
+
+ def _ustaw_interpolator(self):
+ interpolator = gr.fractional_interpolator_cc(0, self.sps)
+ return interpolator
+
+ def _ustaw_odbiornik(self):
+ odbiornik = gsm.receiver_cf(1)
+ return odbiornik
+
+ def _przetworz_opcje(self):
+ parser = OptionParser(option_class=eng_option)
+ parser.add_option("-d", "--decim", type="int", default=128,
+ help="Set USRP decimation rate to DECIM [default=%default]")
+ parser.add_option("-I", "--inputfile", type="string", default="cfile",
+ help="Input filename")
+ parser.add_option("-O", "--outputfile", type="string", default="cfile2.out",
+ help="Output filename")
+ parser.add_option("-R", "--rx-subdev-spec", type="subdev", default=None,
+ help="Select USRP Rx side A or B (default=first one with a daughterboard)")
+ parser.add_option("-f", "--freq", type="eng_float", default="950.4M",
+ help="set frequency to FREQ", metavar="FREQ")
+ parser.add_option("-g", "--gain", type="eng_float", default=None,
+ help="Set gain in dB (default is midpoint)")
+ (options, args) = parser.parse_args ()
+ return (options, args)
+
+def main():
+ try:
+ gsm_receiver_first_blood().run()
+ except KeyboardInterrupt:
+ pass
+
+if __name__ == '__main__':
+ main()
+
+
personal git repositories of Harald Welte. Your mileage may vary