diff options
Diffstat (limited to 'gr-digital/python/digital/gfsk.py')
| -rw-r--r-- | gr-digital/python/digital/gfsk.py | 167 |
1 files changed, 83 insertions, 84 deletions
diff --git a/gr-digital/python/digital/gfsk.py b/gr-digital/python/digital/gfsk.py index 3569ffe6cf..5ce3e85812 100644 --- a/gr-digital/python/digital/gfsk.py +++ b/gr-digital/python/digital/gfsk.py @@ -1,43 +1,42 @@ # -# GFSK modulation and demodulation. +# GFSK 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 +import numpy + from gnuradio import gr from gnuradio import analog -from gnuradio import blocks -import modulation_utils -import digital_swig as digital -from math import pi -import numpy -from pprint import pprint -import inspect +from gnuradio import blocks, filter +from . import modulation_utils +from . import digital_swig as digital -try: - from gnuradio import filter -except ImportError: - import filter_swig as filter # default values (used in __init__ and add_options) _def_samples_per_symbol = 2 @@ -69,22 +68,22 @@ class gfsk_mod(gr.hier_block2): verbose=_def_verbose, log=_def_log): """ - Hierarchical block for Gaussian Frequency Shift Key (GFSK) - modulation. + Hierarchical block for Gaussian Frequency Shift Key (GFSK) + modulation. - The input is a byte stream (unsigned char) and the - output is the complex modulated signal at baseband. + The input is a byte stream (unsigned char) 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) verbose: Print information about modulator? (bool) debug: Print modualtion data to files? (bool) - """ + """ - gr.hier_block2.__init__(self, "gfsk_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, "gfsk_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 @@ -92,43 +91,43 @@ class gfsk_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 = (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]) - # Form Gaussian filter + # Form Gaussian filter # Generate Gaussian response (Needs to be convolved with window below). - self.gaussian_taps = filter.firdes.gaussian( - 1.0, # 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) - - # small amount of output attenuation to prevent clipping USRP sink - self.amp = blocks.multiply_const_cc(0.999) - + self.gaussian_taps = filter.firdes.gaussian( + 1.0, # 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) + + # small amount of output attenuation to prevent clipping USRP sink + self.amp = blocks.multiply_const_cc(0.999) + 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.amp, self) + # Connect & Initialize base class + self.connect(self, self.unpack, self.nrz, self.gaussian_filter, self.fmmod, self.amp, self) def samples_per_symbol(self): return self._samples_per_symbol @@ -138,12 +137,12 @@ class gfsk_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, @@ -184,11 +183,11 @@ class gfsk_demod(gr.hier_block2): verbose=_def_verbose, log=_def_log): """ - Hierarchical block for Gaussian Minimum Shift Key (GFSK) - demodulation. + Hierarchical block for Gaussian Minimum Shift Key (GFSK) + demodulation. - The input is the complex modulated signal at baseband. - The output is a stream of bits packed 1 bit per byte (the LSB) + 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) @@ -196,18 +195,18 @@ class gfsk_demod(gr.hier_block2): log: Print modualtion data to files? (bool) Clock recovery parameters. These all have reasonble defaults. - + Args: gain_mu: controls rate of mu adjustment (float) mu: fractional delay [0.0, 1.0] (float) omega_relative_limit: sets max variation in omega (float, typically 0.000200 (200 ppm)) freq_error: bit rate error as a fraction - float: - """ + float: + """ - gr.hier_block2.__init__(self, "gfsk_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, "gfsk_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 @@ -215,24 +214,24 @@ class gfsk_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 = (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) @@ -241,12 +240,12 @@ class gfsk_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 @@ -256,16 +255,16 @@ class gfsk_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, |