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Diffstat (limited to 'gr-digital/python/gmsk.py')
| -rw-r--r-- | gr-digital/python/gmsk.py | 300 |
1 files changed, 0 insertions, 300 deletions
diff --git a/gr-digital/python/gmsk.py b/gr-digital/python/gmsk.py deleted file mode 100644 index 2c9be056c..000000000 --- a/gr-digital/python/gmsk.py +++ /dev/null @@ -1,300 +0,0 @@ -# -# GMSK modulation and demodulation. -# -# -# Copyright 2005,2006,2007 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. -# - -# See gnuradio-examples/python/digital for examples - -from gnuradio import gr -import modulation_utils -import digital_swig as digital -from math import pi -import numpy -from pprint import pprint -import inspect - -# default values (used in __init__ and add_options) -_def_samples_per_symbol = 2 -_def_bt = 0.35 -_def_verbose = False -_def_log = False - -_def_gain_mu = None -_def_mu = 0.5 -_def_freq_error = 0.0 -_def_omega_relative_limit = 0.005 - - -# FIXME: Figure out how to make GMSK work with pfb_arb_resampler_fff for both -# transmit and receive so we don't require integer samples per symbol. - - -# ///////////////////////////////////////////////////////////////////////////// -# GMSK modulator -# ///////////////////////////////////////////////////////////////////////////// - -class gmsk_mod(gr.hier_block2): - - def __init__(self, - samples_per_symbol=_def_samples_per_symbol, - bt=_def_bt, - verbose=_def_verbose, - log=_def_log): - """ - Hierarchical block for Gaussian Minimum Shift Key (GMSK) - modulation. - - The input is a byte stream (unsigned char) and the - output is the complex modulated signal at baseband. - - @param samples_per_symbol: samples per baud >= 2 - @type samples_per_symbol: integer - @param bt: Gaussian filter bandwidth * symbol time - @type bt: float - @param verbose: Print information about modulator? - @type verbose: bool - @param debug: Print modualtion data to files? - @type debug: bool - """ - - gr.hier_block2.__init__(self, "gmsk_mod", - gr.io_signature(1, 1, gr.sizeof_char), # Input signature - gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature - - samples_per_symbol = int(samples_per_symbol) - self._samples_per_symbol = samples_per_symbol - self._bt = bt - self._differential = False - - if not isinstance(samples_per_symbol, int) or samples_per_symbol < 2: - raise TypeError, ("samples_per_symbol must be an integer >= 2, is %r" % (samples_per_symbol,)) - - ntaps = 4 * samples_per_symbol # up to 3 bits in filter at once - sensitivity = (pi / 2) / samples_per_symbol # phase change per bit = pi / 2 - - # Turn it into NRZ data. - self.nrz = gr.bytes_to_syms() - - # Form Gaussian filter - # Generate Gaussian response (Needs to be convolved with window below). - self.gaussian_taps = gr.firdes.gaussian( - 1, # gain - samples_per_symbol, # symbol_rate - bt, # bandwidth * symbol time - ntaps # number of taps - ) - - self.sqwave = (1,) * samples_per_symbol # rectangular window - self.taps = numpy.convolve(numpy.array(self.gaussian_taps),numpy.array(self.sqwave)) - self.gaussian_filter = gr.interp_fir_filter_fff(samples_per_symbol, self.taps) - - # FM modulation - self.fmmod = gr.frequency_modulator_fc(sensitivity) - - if verbose: - self._print_verbage() - - if log: - self._setup_logging() - - # Connect & Initialize base class - self.connect(self, self.nrz, self.gaussian_filter, self.fmmod, self) - - def samples_per_symbol(self): - return self._samples_per_symbol - - def bits_per_symbol(self=None): # staticmethod that's also callable on an instance - return 1 - bits_per_symbol = staticmethod(bits_per_symbol) # make it a static method. - - - def _print_verbage(self): - print "bits per symbol = %d" % self.bits_per_symbol() - print "Gaussian filter bt = %.2f" % self._bt - - - def _setup_logging(self): - print "Modulation logging turned on." - self.connect(self.nrz, - gr.file_sink(gr.sizeof_float, "nrz.dat")) - self.connect(self.gaussian_filter, - gr.file_sink(gr.sizeof_float, "gaussian_filter.dat")) - self.connect(self.fmmod, - gr.file_sink(gr.sizeof_gr_complex, "fmmod.dat")) - - - def add_options(parser): - """ - Adds GMSK modulation-specific options to the standard parser - """ - parser.add_option("", "--bt", type="float", default=_def_bt, - help="set bandwidth-time product [default=%default] (GMSK)") - add_options=staticmethod(add_options) - - - def extract_kwargs_from_options(options): - """ - Given command line options, create dictionary suitable for passing to __init__ - """ - return modulation_utils.extract_kwargs_from_options(gmsk_mod.__init__, - ('self',), options) - extract_kwargs_from_options=staticmethod(extract_kwargs_from_options) - - - -# ///////////////////////////////////////////////////////////////////////////// -# GMSK demodulator -# ///////////////////////////////////////////////////////////////////////////// - -class gmsk_demod(gr.hier_block2): - - def __init__(self, - samples_per_symbol=_def_samples_per_symbol, - gain_mu=_def_gain_mu, - mu=_def_mu, - omega_relative_limit=_def_omega_relative_limit, - freq_error=_def_freq_error, - verbose=_def_verbose, - log=_def_log): - """ - Hierarchical block for Gaussian Minimum Shift Key (GMSK) - demodulation. - - The input is the complex modulated signal at baseband. - The output is a stream of bits packed 1 bit per byte (the LSB) - - @param samples_per_symbol: samples per baud - @type samples_per_symbol: integer - @param verbose: Print information about modulator? - @type verbose: bool - @param log: Print modualtion data to files? - @type log: bool - - Clock recovery parameters. These all have reasonble defaults. - - @param gain_mu: controls rate of mu adjustment - @type gain_mu: float - @param mu: fractional delay [0.0, 1.0] - @type mu: float - @param omega_relative_limit: sets max variation in omega - @type omega_relative_limit: float, typically 0.000200 (200 ppm) - @param freq_error: bit rate error as a fraction - @param float - """ - - gr.hier_block2.__init__(self, "gmsk_demod", - gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature - gr.io_signature(1, 1, gr.sizeof_char)) # Output signature - - self._samples_per_symbol = samples_per_symbol - self._gain_mu = gain_mu - self._mu = mu - self._omega_relative_limit = omega_relative_limit - self._freq_error = freq_error - self._differential = False - - if samples_per_symbol < 2: - raise TypeError, "samples_per_symbol >= 2, is %f" % samples_per_symbol - - self._omega = samples_per_symbol*(1+self._freq_error) - - if not self._gain_mu: - self._gain_mu = 0.175 - - self._gain_omega = .25 * self._gain_mu * self._gain_mu # critically damped - - # Demodulate FM - sensitivity = (pi / 2) / samples_per_symbol - self.fmdemod = gr.quadrature_demod_cf(1.0 / sensitivity) - - # the clock recovery block tracks the symbol clock and resamples as needed. - # the output of the block is a stream of soft symbols (float) - self.clock_recovery = digital.clock_recovery_mm_ff(self._omega, self._gain_omega, - self._mu, self._gain_mu, - self._omega_relative_limit) - - # slice the floats at 0, outputting 1 bit (the LSB of the output byte) per sample - self.slicer = digital.binary_slicer_fb() - - if verbose: - self._print_verbage() - - if log: - self._setup_logging() - - # Connect & Initialize base class - self.connect(self, self.fmdemod, self.clock_recovery, self.slicer, self) - - def samples_per_symbol(self): - return self._samples_per_symbol - - def bits_per_symbol(self=None): # staticmethod that's also callable on an instance - return 1 - bits_per_symbol = staticmethod(bits_per_symbol) # make it a static method. - - - def _print_verbage(self): - print "bits per symbol = %d" % self.bits_per_symbol() - print "M&M clock recovery omega = %f" % self._omega - print "M&M clock recovery gain mu = %f" % self._gain_mu - print "M&M clock recovery mu = %f" % self._mu - print "M&M clock recovery omega rel. limit = %f" % self._omega_relative_limit - print "frequency error = %f" % self._freq_error - - - def _setup_logging(self): - print "Demodulation logging turned on." - self.connect(self.fmdemod, - gr.file_sink(gr.sizeof_float, "fmdemod.dat")) - self.connect(self.clock_recovery, - gr.file_sink(gr.sizeof_float, "clock_recovery.dat")) - self.connect(self.slicer, - gr.file_sink(gr.sizeof_char, "slicer.dat")) - - def add_options(parser): - """ - Adds GMSK demodulation-specific options to the standard parser - """ - parser.add_option("", "--gain-mu", type="float", default=_def_gain_mu, - help="M&M clock recovery gain mu [default=%default] (GMSK/PSK)") - parser.add_option("", "--mu", type="float", default=_def_mu, - help="M&M clock recovery mu [default=%default] (GMSK/PSK)") - parser.add_option("", "--omega-relative-limit", type="float", default=_def_omega_relative_limit, - help="M&M clock recovery omega relative limit [default=%default] (GMSK/PSK)") - parser.add_option("", "--freq-error", type="float", default=_def_freq_error, - help="M&M clock recovery frequency error [default=%default] (GMSK)") - add_options=staticmethod(add_options) - - def extract_kwargs_from_options(options): - """ - Given command line options, create dictionary suitable for passing to __init__ - """ - return modulation_utils.extract_kwargs_from_options(gmsk_demod.__init__, - ('self',), options) - extract_kwargs_from_options=staticmethod(extract_kwargs_from_options) - - -# -# Add these to the mod/demod registry -# -modulation_utils.add_type_1_mod('gmsk', gmsk_mod) -modulation_utils.add_type_1_demod('gmsk', gmsk_demod) |