| #!/usr/bin/env python2 |
| # -*- coding: utf-8 -*- |
| # @file |
| # @author Pieter Robyns <pieter.robyns@uhasselt.be> |
| # @section LICENSE |
| # |
| # Gr-gsm 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. |
| # |
| # Gr-gsm 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 gr-gsm; see the file COPYING. If not, write to |
| # the Free Software Foundation, Inc., 51 Franklin Street, |
| # Boston, MA 02110-1301, USA. |
| # |
| # |
| |
| ################################################## |
| # gr-gsm channelizer |
| # |
| # Standalone application to channelize a wideband |
| # GSM capture file into multiple seperate capture |
| # files for the specified ARFCNs. |
| ################################################## |
| |
| from gnuradio import blocks |
| from gnuradio import eng_notation |
| from gnuradio import filter |
| from gnuradio import gr |
| from gnuradio.eng_option import eng_option |
| from gnuradio.filter import firdes |
| from argparse import ArgumentParser, ArgumentTypeError, RawDescriptionHelpFormatter |
| import grgsm.arfcn as arfcn |
| import os |
| |
| EXTRA_HELP = """ |
| Example usage: |
| gsm_channelize.py -f my_wideband_capture.cfile -c 925.2e6 990 991 992 993 994 995 1019 1020 1021 1022 1023 |
| |
| The above example will channelize my_wideband_capture.cfile, in this case a cfile captured at |
| 925.2 MHz centered (ARFCN 975) and 20 Msps. As a result, 12 files will be generated for |
| ARFCNs 975 - 1023 at 1 Msps each. |
| """ |
| |
| def eng_float(value): |
| try: |
| return eng_notation.str_to_num(value) |
| except: |
| raise ArgumentTypeError("invalid engineering notation value: {0}".format(value)) |
| |
| def gsm_band(value): |
| choices = arfcn.get_bands() |
| if value in choices: |
| return value |
| else: |
| raise ArgumentTypeError("invalid GSM band: {0}. Possible choices are: {1}".format(value, choices)) |
| |
| class gsm_channelize(gr.top_block): |
| def __init__(self, channels, decim, ch_width, ch_twidth, fc, band, samp_rate, path): |
| gr.top_block.__init__(self, "gsm_channelize") |
| |
| ################################################## |
| # Parameters |
| ################################################## |
| self.channels = channels |
| self.decim = decim |
| self.ch_width = ch_width |
| self.ch_twidth = ch_twidth |
| self.fc = fc |
| self.band = band |
| self.samp_rate = samp_rate |
| self.blocks_fir_filters = {} |
| self.blocks_file_sinks = {} |
| |
| ################################################## |
| # Blocks and connections |
| ################################################## |
| self.blocks_file_source = blocks.file_source(gr.sizeof_gr_complex, path, False) |
| |
| c0_arfcn = arfcn.downlink2arfcn(fc, band) |
| self.channels.insert(0, c0_arfcn) |
| print("Extracting channels %s, given that the center frequency is at ARFCN %d (%s)" % (str(channels), c0_arfcn, eng_notation.num_to_str(fc))) |
| |
| for channel in channels: |
| channel_freq = arfcn.arfcn2downlink(channel, band) |
| if channel_freq is None: |
| print("Warning: invalid ARFCN %d for band %s" % (channel, band)) |
| continue |
| freq_diff = channel_freq - fc |
| print("ARFCN %d is at C0 %+d KHz" % (channel, int(freq_diff / 1000.0))) |
| |
| self.blocks_fir_filters[channel] = filter.freq_xlating_fir_filter_ccc(decim, (firdes.low_pass(1, samp_rate, ch_width, ch_twidth)), freq_diff, samp_rate) |
| self.connect((self.blocks_file_source, 0), (self.blocks_fir_filters[channel], 0)) |
| |
| self.blocks_file_sinks[channel] = blocks.file_sink(gr.sizeof_gr_complex, "./gsm_channelizer/out_" + str(channel) + ".cfile", False) |
| self.blocks_file_sinks[channel].set_unbuffered(False) |
| self.connect((self.blocks_fir_filters[channel], 0), (self.blocks_file_sinks[channel], 0)) |
| |
| |
| if __name__ == '__main__': |
| parser = ArgumentParser(formatter_class=RawDescriptionHelpFormatter, description='Split wideband a GSM capture into seperate files per ARFCN.', epilog=EXTRA_HELP) |
| parser.add_argument(dest="channel", type=int, nargs='+', |
| help="List of ARFCNs") |
| parser.add_argument("-w", "--width", dest="width", type=eng_float, default=eng_notation.num_to_str(200000), |
| help="Channel lowpass width [default=%(default)s]") |
| parser.add_argument("-t", "--transition-width", dest="twidth", type=eng_float, default=eng_notation.num_to_str(50000), |
| help="Channel lowpass transition width [default=%(default)s]") |
| parser.add_argument("-s", "--samp-rate", dest="samp_rate", type=eng_float, default=eng_notation.num_to_str(2e7), |
| help="Sample rate of the wideband capture file [default=%(default)s]") |
| parser.add_argument("-o", "--out-samp-rate", dest="out_samp_rate", type=eng_float, default=eng_notation.num_to_str(1e6), |
| help="Sample rate of the output capture files [default=%(default)s]") |
| parser.add_argument("-b", "--band", dest="band", type=gsm_band, default='E-GSM', |
| help="GSM band [default=%(default)s]") |
| parser.add_argument("-f", "--cfile", dest="path", type=str, required=True, |
| help="Path to wideband GSM capture file") |
| parser.add_argument("-c", "--C0", dest="fc", type=eng_float, default=eng_notation.num_to_str(925.2e6), required=True, |
| help="C0 (BCCH) channel frequency in Hz [default=%(default)s]") |
| args = parser.parse_args() |
| |
| if not os.path.exists("./gsm_channelizer"): |
| os.makedirs("./gsm_channelizer") |
| |
| if not os.path.exists(args.path): |
| raise IOError(args.path + " does not exist") |
| |
| if args.samp_rate % args.out_samp_rate != 0: |
| raise Exception("Input sample rate should be multiple of output sample rate in order to get integer decimation.") |
| |
| decim = int(args.samp_rate / args.out_samp_rate) |
| print("Input sample rate: " + eng_notation.num_to_str(args.samp_rate)) |
| print("Output sample rate: " + eng_notation.num_to_str(args.out_samp_rate)) |
| print("==> using decimation of " + str(decim)) |
| |
| tb = gsm_channelize(channels=args.channel, |
| decim=decim, |
| ch_width=args.width, |
| ch_twidth=args.twidth, |
| fc=args.fc, |
| band=args.band, |
| samp_rate=args.samp_rate, |
| path=args.path) |
| tb.start() |
| tb.wait() |
| print("Done!") |