gr-gsm/apps/helpers/grgsm_channelize.py

169 lines
7.3 KiB
Python
Executable File

#!/usr/bin/env python2
# -*- coding: utf-8 -*-
# @file
# @author (C) 2015 by 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
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!")