#!/usr/bin/env python2 # -*- coding: utf-8 -*- # @file # @author (C) 2015 by Pieter Robyns # @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 from gnuradio.filter import pfb import math import os EXTRA_HELP = """ Example usage: grgsm_channelize.py -c my_wideband_capture.cfile -f 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 2 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 grgsm_channelize(gr.top_block): def __init__(self, channels, resamp_rate, fc, band, samp_rate, input_file, dest_dir, data_type="complex"): gr.top_block.__init__(self, "grgsm_channelize") ################################################## # Parameters ################################################## self.channels = channels self.resamp_rate = resamp_rate self.fc = fc self.band = band self.samp_rate = samp_rate self.blocks_resamplers = {} self.blocks_rotators = {} self.blocks_file_sinks = {} ################################################## # Blocks and connections ################################################## self.source = None if data_type == "ishort": self.blocks_file_source = blocks.file_source(gr.sizeof_short, input_file, False) self.source = blocks.interleaved_short_to_complex(False, False) self.connect((self.blocks_file_source, 0), (self.source, 0)) elif data_type == "complex": self.source = blocks.file_source(gr.sizeof_gr_complex, input_file, False) fc_str = eng_notation.num_to_str(fc) print("Extracting channels %s, given that the center frequency is at %s" % (str(channels), 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 freq_diff_str = "+" if 0 <= freq_diff else "" freq_diff_str += eng_notation.num_to_str(freq_diff) print("ARFCN %d is at %sHz %sHz" % (channel, fc_str, freq_diff_str)) self.blocks_resamplers[channel] = pfb.arb_resampler_ccf( resamp_rate, taps=None, flt_size=32) self.blocks_rotators[channel] = blocks.rotator_cc(-2*math.pi*(freq_diff)/samp_rate) self.connect( (self.source, 0), (self.blocks_rotators[channel], 0) ) self.connect( (self.blocks_rotators[channel], 0), (self.blocks_resamplers[channel], 0) ) self.blocks_file_sinks[channel] = blocks.file_sink(gr.sizeof_gr_complex, dest_dir+"/out_" + str(channel) + ".cfile", False) self.blocks_file_sinks[channel].set_unbuffered(False) self.connect((self.blocks_resamplers[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.', add_help=True, epilog=EXTRA_HELP) parser.add_argument(dest="channel", type=int, nargs='+', help="List of ARFCNs") parser.add_argument("-s", "--samp-rate", dest="samp_rate", type=eng_float, default=eng_notation.num_to_str(2e6), help="Sample rate of the wideband capture file [default=%(default)s]") parser.add_argument("-f", "--fc", dest="fc", type=eng_float, default=eng_notation.num_to_str(935e6), required=True, help="Carrier frequency in Hz [default=%(default)s]") parser.add_argument("-b", "--band", dest="band", type=gsm_band, default='E-GSM', help="GSM band [default=%(default)s]") #TODO: add automatic discovery based on fc 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("-i", "--input_file", dest="input_file", type=str, required=True, help="Path to wideband GSM capture file") parser.add_argument("-t", "--data_type", dest="data_type", type=str, choices=["complex","ishort"], default="complex", help="Type of the input file [default=%(default)s]") parser.add_argument("-d", "--dest_dir", dest="dest_dir", type=str, help="Destination directory - if not given defaults to input file name without extension") args = parser.parse_args() if not os.path.exists(args.input_file): raise IOError(args.input_file + " does not exist") input_filename, _ = os.path.splitext(os.path.basename(args.input_file)) if args.dest_dir is None: args.dest_dir = input_filename if not os.path.exists("./"+args.dest_dir): os.makedirs("./"+args.dest_dir) 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.") resamp_rate = args.out_samp_rate / args.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 resample rate of " + str(resamp_rate)) tb = grgsm_channelize(channels=args.channel, resamp_rate=resamp_rate, fc=args.fc, band=args.band, samp_rate=args.samp_rate, input_file=args.input_file, dest_dir=args.dest_dir, data_type=args.data_type ) tb.start() tb.wait() print("Done!")