diff options
Diffstat (limited to 'gr-digital/python/gmsk.py')
| -rw-r--r-- | gr-digital/python/gmsk.py | 95 |
1 files changed, 46 insertions, 49 deletions
diff --git a/gr-digital/python/gmsk.py b/gr-digital/python/gmsk.py index 2c9be056c2..c0f5c439aa 100644 --- a/gr-digital/python/gmsk.py +++ b/gr-digital/python/gmsk.py @@ -2,7 +2,7 @@ # GMSK modulation and demodulation. # # -# Copyright 2005,2006,2007 Free Software Foundation, Inc. +# Copyright 2005-2007,2012 Free Software Foundation, Inc. # # This file is part of GNU Radio # @@ -25,6 +25,7 @@ # See gnuradio-examples/python/digital for examples from gnuradio import gr +from gnuradio import analog import modulation_utils import digital_swig as digital from math import pi @@ -32,6 +33,12 @@ import numpy from pprint import pprint import inspect +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 _def_bt = 0.35 @@ -53,28 +60,25 @@ _def_omega_relative_limit = 0.005 # ///////////////////////////////////////////////////////////////////////////// class gmsk_mod(gr.hier_block2): + """ + 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. + + Args: + samples_per_symbol: samples per baud >= 2 (integer) + bt: Gaussian filter bandwidth * symbol time (float) + verbose: Print information about modulator? (boolean) + debug: Print modulation data to files? (boolean) + """ 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 @@ -92,11 +96,13 @@ class gmsk_mod(gr.hier_block2): sensitivity = (pi / 2) / samples_per_symbol # phase change per bit = pi / 2 # Turn it into NRZ data. - self.nrz = gr.bytes_to_syms() + #self.nrz = digital.bytes_to_syms() + self.unpack = gr.packed_to_unpacked_bb(1, gr.GR_MSB_FIRST) + self.nrz = digital.chunks_to_symbols_bf([-1, 1], 1) # Form Gaussian filter # Generate Gaussian response (Needs to be convolved with window below). - self.gaussian_taps = gr.firdes.gaussian( + self.gaussian_taps = filter.firdes.gaussian( 1, # gain samples_per_symbol, # symbol_rate bt, # bandwidth * symbol time @@ -105,10 +111,10 @@ class gmsk_mod(gr.hier_block2): 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) + self.gaussian_filter = filter.interp_fir_filter_fff(samples_per_symbol, self.taps) # FM modulation - self.fmmod = gr.frequency_modulator_fc(sensitivity) + self.fmmod = analog.frequency_modulator_fc(sensitivity) if verbose: self._print_verbage() @@ -117,7 +123,7 @@ class gmsk_mod(gr.hier_block2): self._setup_logging() # Connect & Initialize base class - self.connect(self, self.nrz, self.gaussian_filter, self.fmmod, self) + self.connect(self, self.unpack, self.nrz, self.gaussian_filter, self.fmmod, self) def samples_per_symbol(self): return self._samples_per_symbol @@ -166,7 +172,23 @@ class gmsk_mod(gr.hier_block2): # ///////////////////////////////////////////////////////////////////////////// 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) + verbose: Print information about modulator? (boolean) + log: Print modualtion data to files? (boolean) + 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) + freq_error: bit rate error as a fraction (float) + """ + def __init__(self, samples_per_symbol=_def_samples_per_symbol, gain_mu=_def_gain_mu, @@ -175,31 +197,6 @@ class gmsk_demod(gr.hier_block2): 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 @@ -224,7 +221,7 @@ class gmsk_demod(gr.hier_block2): # Demodulate FM sensitivity = (pi / 2) / samples_per_symbol - self.fmdemod = gr.quadrature_demod_cf(1.0 / sensitivity) + 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) |