diff options
Diffstat (limited to 'gnuradio-examples/python/dect/dect_receiver.py')
-rw-r--r-- | gnuradio-examples/python/dect/dect_receiver.py | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/gnuradio-examples/python/dect/dect_receiver.py b/gnuradio-examples/python/dect/dect_receiver.py new file mode 100644 index 000000000..89e60c949 --- /dev/null +++ b/gnuradio-examples/python/dect/dect_receiver.py @@ -0,0 +1,80 @@ +#!/usr/bin/env python +# +# Copyright 2007 Free Software Foundation, Inc. +# +# This file is part of GNU Radio +# +# GNU Radio is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3, or (at your option) +# any later version. +# +# GNU Radio is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with GNU Radio; see the file COPYING. If not, write to +# the Free Software Foundation, Inc., 51 Franklin Street, +# Boston, MA 02110-1301, USA. +# + +from gnuradio import gr, optfir, blks2 +from usrp_source import usrp_source_c + +_dect_symbol_rate = 1.152e6 +_dect_occupied_bandwidth = _dect_symbol_rate * 1.03 # BT=0.5 +_dect_channel_bandwidth = 1.728e6 + +# Top-level hierarchical block that implements DECT demodulation and +# decoding. +class dect_receiver(gr.top_block): + def __init__(self, options): + gr.top_block.__init__(self, "dect_receiver") + self._options = options + + # Need greater than 2 samples per symbol. This makes a decimation + # rate of 26 and a samples per symbol of 2.136752 + if_rate = 2.461538e6 + self._usrp = usrp_source_c(which=0, + subdev_spec=options.rx_subdev_spec, + if_rate=if_rate, + gain=options.gain, + freq=options.freq, + calibration=options.calibration, + verbose=options.verbose) + + # Filter baseband to 1.186 MHz passband, 1.728 MHz stopband + chan_taps = optfir.low_pass(1.0, # Gain + if_rate, # Sample rate + _dect_occupied_bandwidth/2, # One sided modulation bandwidth + _dect_channel_bandwidth/2, # One sided channel bandwidth + 1.0, # Passband ripple (db) + 60) # Stopband attenuation (db) + if self._options.verbose: + print "Channel filter has", len(chan_taps), "taps" + self._channel_filter = gr.freq_xlating_fir_filter_ccf(1, # Decimation rate + chan_taps, # Filter taps + 0.0, # Offset frequency + if_rate) # Sample rate + + self._demod = blks2.gmsk_demod(samples_per_symbol=if_rate/_dect_symbol_rate, + verbose=options.verbose) + + self._sink = gr.null_sink(gr.sizeof_char) + self.connect(self._usrp, self._channel_filter, self._demod, self._sink) + + # Log baseband to file if requested + if options.log_baseband is not None: + if options.verbose: + print "Logging baseband to file", options.log_baseband + self.baseband_log = gr.file_sink(gr.sizeof_gr_complex, options.log_baseband) + self.connect(self._channel_filter, self.baseband_log) + + # Log demodulator output to file if requested + if options.log_demod is not None: + if options.verbose: + print "Logging demodulator to file", options.log_demod + self.demod_log = gr.file_sink(gr.sizeof_char, options.log_demod) + self.connect(self._demod, self.demod_log) |