diff options
Diffstat (limited to 'gr-digital/python/digital/gmsk.py')
| -rw-r--r-- | gr-digital/python/digital/gmsk.py | 135 |
1 files changed, 70 insertions, 65 deletions
diff --git a/gr-digital/python/digital/gmsk.py b/gr-digital/python/digital/gmsk.py index e7a92a95db..5e25a3d3a1 100644 --- a/gr-digital/python/digital/gmsk.py +++ b/gr-digital/python/digital/gmsk.py @@ -1,26 +1,31 @@ # -# GMSK modulation and demodulation. +# GMSK modulation and demodulation. # # # Copyright 2005-2007,2012 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 __future__ import print_function +from __future__ import absolute_import +from __future__ import division +from __future__ import unicode_literals # See gnuradio-examples/python/digital for examples @@ -31,8 +36,8 @@ import inspect import numpy from gnuradio import gr, blocks, analog, filter -import modulation_utils -import digital_swig as digital +from . import modulation_utils +from . import digital_swig as digital # default values (used in __init__ and add_options) _def_samples_per_symbol = 2 @@ -58,10 +63,10 @@ class gmsk_mod(gr.hier_block2): """ Hierarchical block for Gaussian Minimum Shift Key (GMSK) modulation. - + The input is a byte stream (unsigned char with packed bits) and the output is the complex modulated signal at baseband. - + Args: samples_per_symbol: samples per baud >= 2 (integer) bt: Gaussian filter bandwidth * symbol time (float) @@ -75,9 +80,9 @@ class gmsk_mod(gr.hier_block2): verbose=_def_verbose, log=_def_log): - 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 + 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 @@ -85,40 +90,40 @@ class gmsk_mod(gr.hier_block2): 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,)) + 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 + ntaps = 4 * samples_per_symbol # up to 3 bits in filter at once + sensitivity = (old_div(pi / 2), samples_per_symbol) # phase change per bit = pi / 2 - # Turn it into NRZ data. - #self.nrz = digital.bytes_to_syms() + # Turn it into NRZ data. + #self.nrz = digital.bytes_to_syms() self.unpack = blocks.packed_to_unpacked_bb(1, gr.GR_MSB_FIRST) self.nrz = digital.chunks_to_symbols_bf([-1, 1], 1) - # Form Gaussian filter + # Form Gaussian filter # Generate Gaussian response (Needs to be convolved with window below). - self.gaussian_taps = filter.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 = filter.interp_fir_filter_fff(samples_per_symbol, self.taps) - - # FM modulation - self.fmmod = analog.frequency_modulator_fc(sensitivity) - + self.gaussian_taps = filter.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 = filter.interp_fir_filter_fff(samples_per_symbol, self.taps) + + # FM modulation + self.fmmod = analog.frequency_modulator_fc(sensitivity) + if verbose: self._print_verbage() - + if log: self._setup_logging() - # Connect & Initialize base class - self.connect(self, self.unpack, self.nrz, self.gaussian_filter, self.fmmod, self) + # Connect & Initialize base class + self.connect(self, self.unpack, self.nrz, self.gaussian_filter, self.fmmod, self) def samples_per_symbol(self): return self._samples_per_symbol @@ -128,12 +133,12 @@ class gmsk_mod(gr.hier_block2): return 1 def _print_verbage(self): - print "bits per symbol = %d" % self.bits_per_symbol() - print "Gaussian filter bt = %.2f" % self._bt + 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." + print("Modulation logging turned on.") self.connect(self.nrz, blocks.file_sink(gr.sizeof_float, "nrz.dat")) self.connect(self.gaussian_filter, @@ -166,10 +171,10 @@ class gmsk_demod(gr.hier_block2): """ 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) - + Args: samples_per_symbol: samples per baud (integer) gain_mu: controls rate of mu adjustment (float) @@ -179,7 +184,7 @@ class gmsk_demod(gr.hier_block2): verbose: Print information about modulator? (boolean) log: Print modualtion data to files? (boolean) """ - + def __init__(self, samples_per_symbol=_def_samples_per_symbol, gain_mu=_def_gain_mu, @@ -189,9 +194,9 @@ class gmsk_demod(gr.hier_block2): verbose=_def_verbose, log=_def_log): - 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 + 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 @@ -199,24 +204,24 @@ class gmsk_demod(gr.hier_block2): 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 + 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 = analog.quadrature_demod_cf(1.0 / sensitivity) + self._gain_omega = .25 * self._gain_mu * self._gain_mu # critically damped - # 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, + # Demodulate FM + sensitivity = (old_div(pi / 2), samples_per_symbol) + self.fmdemod = analog.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) @@ -225,12 +230,12 @@ class gmsk_demod(gr.hier_block2): 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) + # 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 @@ -240,16 +245,16 @@ class gmsk_demod(gr.hier_block2): return 1 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 + 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." + print("Demodulation logging turned on.") self.connect(self.fmdemod, blocks.file_sink(gr.sizeof_float, "fmdemod.dat")) self.connect(self.clock_recovery, |