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[Commit-gnuradio] r4202 - gnuradio/branches/developers/trondeau/digital-
From: |
trondeau |
Subject: |
[Commit-gnuradio] r4202 - gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2 |
Date: |
Tue, 26 Dec 2006 21:00:21 -0700 (MST) |
Author: trondeau
Date: 2006-12-26 21:00:21 -0700 (Tue, 26 Dec 2006)
New Revision: 4202
Added:
gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2/dqpsk.py
gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2/gmsk.py
Modified:
gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2/Makefile.am
Log:
adding gmsk and dqpsk capabilities to example code with hier_block2
Modified:
gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2/Makefile.am
===================================================================
---
gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2/Makefile.am
2006-12-27 03:59:24 UTC (rev 4201)
+++
gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2/Makefile.am
2006-12-27 04:00:21 UTC (rev 4202)
@@ -29,6 +29,8 @@
grblkspython_PYTHON = \
__init__.py \
dbpsk.py \
+ dqpsk.py \
+ gmsk.py \
pkt.py \
psk.py
Added:
gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2/dqpsk.py
===================================================================
---
gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2/dqpsk.py
(rev 0)
+++
gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2/dqpsk.py
2006-12-27 04:00:21 UTC (rev 4202)
@@ -0,0 +1,410 @@
+#
+# Copyright 2005,2006 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 2, 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
+
+"""
+differential QPSK modulation and demodulation.
+"""
+
+from gnuradio import gr, gru, modulation_utils
+from math import pi, sqrt
+import psk
+import cmath
+import Numeric
+from pprint import pprint
+
+# default values (used in __init__ and add_options)
+_def_samples_per_symbol = 2
+_def_excess_bw = 0.35
+_def_gray_code = True
+_def_verbose = False
+_def_log = False
+
+_def_costas_alpha = None
+_def_gain_mu = 0.01
+_def_mu = 0.00
+_def_omega_relative_limit = 0.005
+
+
+# /////////////////////////////////////////////////////////////////////////////
+# DQPSK modulator
+# /////////////////////////////////////////////////////////////////////////////
+
+class dqpsk_mod(gr.hier_block2):
+ def __init__(self,
+ samples_per_symbol=_def_samples_per_symbol,
+ excess_bw=_def_excess_bw,
+ gray_code=_def_gray_code,
+ verbose=_def_verbose,
+ log=_def_log):
+ """
+ Hierarchical block for RRC-filtered QPSK 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 symbol >= 2
+ @type samples_per_symbol: integer
+ @param excess_bw: Root-raised cosine filter excess bandwidth
+ @type excess_bw: float
+ @param gray_code: Tell modulator to Gray code the bits
+ @type gray_code: bool
+ @param verbose: Print information about modulator?
+ @type verbose: bool
+ @param debug: Print modualtion data to files?
+ @type debug: bool
+ """
+
+ gr.hier_block2.__init__(self, "dqpsk_mod",
+ gr.io_signature(1,1,gr.sizeof_char), #
Input signature
+ gr.io_signature(1,1,gr.sizeof_gr_complex)) #
Output signature
+
+ self._samples_per_symbol = samples_per_symbol
+ self._excess_bw = excess_bw
+ self._gray_code = gray_code
+
+ if not isinstance(samples_per_symbol, int) or samples_per_symbol < 2:
+ raise TypeError, ("sbp must be an integer >= 2, is %d" %
samples_per_symbol)
+
+ ntaps = 11 * samples_per_symbol
+
+ arity = pow(2,self.bits_per_symbol())
+
+ # turn bytes into k-bit vectors
+ self.bytes2chunks = \
+ gr.packed_to_unpacked_bb(self.bits_per_symbol(), gr.GR_MSB_FIRST)
+
+ if self._gray_code:
+ self.symbol_mapper = gr.map_bb(psk.binary_to_gray[arity])
+ else:
+ self.symbol_mapper = gr.map_bb(psk.binary_to_ungray[arity])
+
+ self.diffenc = gr.diff_encoder_bb(arity)
+
+ rot = .707 + .707j
+ rotated_const = map(lambda pt: pt * rot, psk.constellation[arity])
+ self.chunks2symbols = gr.chunks_to_symbols_bc(rotated_const)
+
+ # pulse shaping filter
+ self.rrc_taps = gr.firdes.root_raised_cosine(
+ self._samples_per_symbol, # gain (sps since we're interpolating by
sps)
+ self._samples_per_symbol, # sampling rate
+ 1.0, # symbol rate
+ self._excess_bw, # excess bandwidth (roll-off factor)
+ ntaps)
+
+ self.rrc_filter = gr.interp_fir_filter_ccf(self._samples_per_symbol,
self.rrc_taps)
+
+ # Define components from objects
+ self.define_component("bytes2chunks", self.bytes2chunks)
+ self.define_component("symbol_mapper", self.symbol_mapper)
+ self.define_component("diffenc", self.diffenc)
+ self.define_component("chunks2symbols", self.chunks2symbols)
+ self.define_component("rrc_filter", self.rrc_filter)
+
+ # Connect components
+ self.connect("self", 0, "bytes2chunks", 0)
+ self.connect("bytes2chunks", 0, "symbol_mapper", 0)
+ self.connect("symbol_mapper", 0, "diffenc", 0)
+ self.connect("diffenc", 0, "chunks2symbols", 0)
+ self.connect("chunks2symbols", 0, "rrc_filter", 0)
+ self.connect("rrc_filter", 0, "self", 0)
+
+ if verbose:
+ self._print_verbage()
+
+ if log:
+ self._setup_logging()
+
+ 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 2
+ bits_per_symbol = staticmethod(bits_per_symbol) # make it a static
method. RTFM
+
+ def _print_verbage(self):
+ print "bits per symbol = %d" % self.bits_per_symbol()
+ print "Gray code = %s" % self._gray_code
+ print "RRS roll-off factor = %f" % self._excess_bw
+
+ def _setup_logging(self):
+ print "Modulation logging turned on."
+ self.define_component("bytes2chunks_dat", gr.file_sink(gr.sizeof_char,
"tx_bytes2chunks.dat"))
+ self.define_component("symbol_mapper_dat",
gr.file_sink(gr.sizeof_char, "tx_symbol_mapper.dat"))
+ self.define_component("diffenc_dat", gr.file_sink(gr.sizeof_char,
"tx_diffenc.dat"))
+ self.define_component("chunks2symbols_dat",
gr.file_sink(gr.sizeof_gr_complex, "tx_chunks2symbols.dat"))
+ self.define_component("rrc_filter_dat",
gr.file_sink(gr.sizeof_gr_complex, "tx_rrc_filter.dat"))
+
+ self.connect("bytes2chunks", 0, "bytes2chunks_dat", 0)
+ self.connect("symbol_mapper", 0, "symbol_mapper_dat", 0)
+ self.connect("diffenc", 0, "diffenc_dat", 0)
+ self.connect("chunks2symbols", 0, "chunks2symbols_dat", 0)
+ self.connect("rrc_filter", 0, "rrc_filter_dat", 0)
+
+ def add_options(parser):
+ """
+ Adds QPSK modulation-specific options to the standard parser
+ """
+ parser.add_option("", "--excess-bw", type="float",
default=_def_excess_bw,
+ help="set RRC excess bandwith factor
[default=%default] (PSK)")
+ parser.add_option("", "--no-gray-code", dest="gray_code",
+ action="store_false", default=_def_gray_code,
+ help="disable gray coding on modulated bits (PSK)")
+ 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(dqpsk_mod.__init__,
+ ('self', 'fg'),
options)
+ extract_kwargs_from_options=staticmethod(extract_kwargs_from_options)
+
+
+# /////////////////////////////////////////////////////////////////////////////
+# DQPSK demodulator
+#
+# Differentially coherent detection of differentially encoded qpsk
+# /////////////////////////////////////////////////////////////////////////////
+
+class dqpsk_demod(gr.hier_block2):
+
+ def __init__(self,
+ samples_per_symbol=_def_samples_per_symbol,
+ excess_bw=_def_excess_bw,
+ costas_alpha=_def_costas_alpha,
+ gain_mu=_def_gain_mu,
+ mu=_def_mu,
+ omega_relative_limit=_def_omega_relative_limit,
+ gray_code=_def_gray_code,
+ verbose=_def_verbose,
+ log=_def_log):
+ """
+ Hierarchical block for RRC-filtered DQPSK demodulation
+
+ The input is the complex modulated signal at baseband.
+ The output is a stream of bits packed 1 bit per byte (LSB)
+
+ @param samples_per_symbol: samples per symbol >= 2
+ @type samples_per_symbol: float
+ @param excess_bw: Root-raised cosine filter excess bandwidth
+ @type excess_bw: float
+ @param costas_alpha: loop filter gain
+ @type costas_alphas: float
+ @param gain_mu: for M&M block
+ @type gain_mu: float
+ @param mu: for M&M block
+ @type mu: float
+ @param omega_relative_limit: for M&M block
+ @type omega_relative_limit: float
+ @param gray_code: Tell modulator to Gray code the bits
+ @type gray_code: bool
+ @param verbose: Print information about modulator?
+ @type verbose: bool
+ @param debug: Print modualtion data to files?
+ @type debug: bool
+ """
+
+ gr.hier_block2.__init__(self, "dqpsk_mod",
+ 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._excess_bw = excess_bw
+ self._costas_alpha = costas_alpha
+ self._gain_mu = gain_mu
+ self._mu = mu
+ self._omega_relative_limit = omega_relative_limit
+ self._gray_code = gray_code
+
+ if samples_per_symbol < 2:
+ raise TypeError, "sbp must be >= 2, is %d" % samples_per_symbol
+
+ arity = pow(2,self.bits_per_symbol())
+
+ # Automatic gain control
+ scale = (1.0/16384.0)
+ self.pre_scaler = gr.multiply_const_cc(scale) # scale the signal
from full-range to +-1
+ self.agc = gr.feedforward_agc_cc(16, 1.0)
+
+ # Costas loop (carrier tracking)
+ if self._costas_alpha is None: # If no alpha value was specified by
the user
+ alpha_dir = {2:0.075, 3:0.09, 4:0.09, 5:0.095, 6:0.10, 7:0.105}
+ self._costas_alpha = alpha_dir[self._samples_per_symbol]
+
+ costas_order = 4
+ # The value of beta is now set to be underdamped; this value can have
a huge impact on the
+ # performance of QPSK. Set to 0.25 for critically damped or higher for
underdamped responses.
+ beta = .35 * self._costas_alpha * self._costas_alpha
+ self.costas_loop = gr.costas_loop_cc(self._costas_alpha, beta, 0.02,
-0.02, costas_order)
+
+ # RRC data filter
+ ntaps = 11 * samples_per_symbol
+ self.rrc_taps = gr.firdes.root_raised_cosine(
+ self._samples_per_symbol, # gain
+ self._samples_per_symbol, # sampling rate
+ 1.0, # symbol rate
+ self._excess_bw, # excess bandwidth (roll-off factor)
+ ntaps)
+
+ self.rrc_filter=gr.fir_filter_ccf(1, self.rrc_taps)
+
+ # symbol clock recovery
+ omega = self._samples_per_symbol
+ gain_omega = .25 * self._gain_mu * self._gain_mu
+ self.clock_recovery=gr.clock_recovery_mm_cc(omega, gain_omega,
+ self._mu, self._gain_mu,
+ self._omega_relative_limit)
+
+ self.diffdec = gr.diff_decoder_bb(arity)
+
+ # find closest constellation point
+ rot = 1
+ rot = .707 + .707j
+ rotated_const = map(lambda pt: pt * rot, psk.constellation[arity])
+
+ self.slicer = gr.constellation_decoder_cb(rotated_const, range(arity))
+
+ if self._gray_code:
+ self.symbol_mapper = gr.map_bb(psk.gray_to_binary[arity])
+ else:
+ self.symbol_mapper = gr.map_bb(psk.ungray_to_binary[arity])
+
+ # unpack the k bit vector into a stream of bits
+ self.unpack = gr.unpack_k_bits_bb(self.bits_per_symbol())
+
+ # Define components
+ self.define_component("pre_scaler", self.pre_scaler)
+ self.define_component("agc", self.agc)
+ self.define_component("costas_loop", self.costas_loop)
+ self.define_component("rrc_filter", self.rrc_filter)
+ self.define_component("clock_recovery", self.clock_recovery)
+ self.define_component("slicer", self.slicer)
+ self.define_component("diffdec", self.diffdec)
+ self.define_component("symbol_mapper", self.symbol_mapper)
+ self.define_component("unpack", self.unpack)
+
+ # Connect and Initialize base class
+ self.connect("self", 0, "pre_scaler", 0)
+ self.connect("pre_scaler", 0, "agc", 0)
+ self.connect("agc", 0, "costas_loop", 0)
+ self.connect("costas_loop", 0, "rrc_filter", 0)
+ self.connect("rrc_filter", 0, "clock_recovery", 0)
+ self.connect("clock_recovery", 0, "slicer", 0)
+ self.connect("slicer", 0, "diffdec", 0)
+ self.connect("diffdec", 0, "symbol_mapper", 0)
+ self.connect("symbol_mapper", 0, "unpack", 0)
+ self.connect("unpack", 0, "self", 0)
+
+ if verbose:
+ self._print_verbage()
+
+ if log:
+ self._setup_logging()
+
+ 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 2
+ bits_per_symbol = staticmethod(bits_per_symbol) # make it a static
method. RTFM
+
+ def _print_verbage(self):
+ print "bits per symbol = %d" % self.bits_per_symbol()
+ print "Gray code = %s" % self._gray_code
+ print "RRC roll-off factor = %.2f" % self._excess_bw
+ print "Costas Loop alpha = %.5f" % self._costas_alpha
+ print "M&M symbol sync gain = %.5f" % self._gain_mu
+ print "M&M symbol sync mu = %.5f" % self._mu
+ print "M&M omega relative limit = %.5f" % self._omega_relative_limit
+
+
+ def _setup_logging(self):
+ print "Demodulation logging turned on."
+ self.define_component("prescaler_dat",
+ gr.file_sink(gr.sizeof_gr_complex,
"rx_prescaler.dat"))
+ self.define_component("agc_dat",
+ gr.file_sink(gr.sizeof_gr_complex, "rx_agc.dat"))
+ self.define_component("costas_loop_dat",
+ gr.file_sink(gr.sizeof_gr_complex,
"costas_loop.dat"))
+ self.define_component("costas_loop_error_dat",
+ gr.file_sink(gr.sizeof_gr_complex,
"costas_loop_error.dat"))
+ self.define_component("rrc_filter_dat",
+ gr.file_sink(gr.sizeof_gr_complex,
"rx_rrc_filter.dat"))
+ self.define_component("clock_recovery_dat",
+ gr.file_sink(gr.sizeof_gr_complex,
"rx_clock_recovery.dat"))
+ self.define_component("clock_recovery_error_dat",
+ gr.file_sink(gr.sizeof_gr_complex,
"rx_clock_recovery_error.dat"))
+ self.define_component("slicer_dat",
+ gr.file_sink(gr.sizeof_char, "rx_slicer.dat"))
+ self.define_component("diffdec_dat",
+ gr.file_sink(gr.sizeof_char, "rx_diffdec.dat"))
+ self.define_component("symbol_mapper_dat",
+ gr.file_sink(gr.sizeof_char,
"rx_symbol_mapper.dat"))
+ self.define_component("unpack_dat",
+ gr.file_sink(gr.sizeof_char, "rx_unpack.dat"))
+
+ self.connect("pre_scaler", 0, "prescaler_dat", 0)
+ self.connect("agc", 0, "agc_dat", 0)
+ self.connect("costas_loop", 0, "costas_loop_dat", 0)
+ self.connect("costas_loop", 1, "costas_loop_error_dat", 0)
+ self.connect("rrc_filter", 0, "rrc_filter_dat", 0)
+ self.connect("clock_recovery", 0, "clock_recovery_dat", 0)
+ self.connect("clock_recovery", 1, "clock_recovery_error_dat", 0)
+ self.connect("slicer", 0, "slicer_dat", 0)
+ self.connect("diffdec", 0, "diffdec_dat", 0)
+ self.connect("symbol_mapper", 0, "symbol_mapper_dat", 0)
+ self.connect("unpack", 0, "unpack_dat", 0)
+
+ def add_options(parser):
+ """
+ Adds modulation-specific options to the standard parser
+ """
+ parser.add_option("", "--excess-bw", type="float",
default=_def_excess_bw,
+ help="set RRC excess bandwith factor
[default=%default] (PSK)")
+ parser.add_option("", "--no-gray-code", dest="gray_code",
+ action="store_false", default=_def_gray_code,
+ help="disable gray coding on modulated bits (PSK)")
+ parser.add_option("", "--costas-alpha", type="float", default=None,
+ help="set Costas loop alpha value [default=%default]
(PSK)")
+ parser.add_option("", "--gain-mu", type="float", default=_def_gain_mu,
+ help="set M&M symbol sync loop gain mu value
[default=%default] (PSK)")
+ parser.add_option("", "--mu", type="float", default=_def_mu,
+ help="set M&M symbol sync loop mu value
[default=%default] (PSK)")
+ 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(
+ dqpsk_demod.__init__, ('self', 'fg'), options)
+ extract_kwargs_from_options=staticmethod(extract_kwargs_from_options)
+
+
+#
+# Add these to the mod/demod registry
+#
+modulation_utils.add_type_1_mod('dqpsk', dqpsk_mod)
+modulation_utils.add_type_1_demod('dqpsk', dqpsk_demod)
Added:
gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2/gmsk.py
===================================================================
---
gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2/gmsk.py
(rev 0)
+++
gnuradio/branches/developers/trondeau/digital-wip2/gnuradio-core/src/python/gnuradio/blksimpl2/gmsk.py
2006-12-27 04:00:21 UTC (rev 4202)
@@ -0,0 +1,305 @@
+#
+# GMSK modulation and demodulation.
+#
+#
+# Copyright 2005,2006 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 2, 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
+from gnuradio import modulation_utils
+from math import pi
+import Numeric
+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 = 0.05
+_def_mu = 0.5
+_def_freq_error = 0.0
+_def_omega_relative_limit = 0.005
+
+
+# /////////////////////////////////////////////////////////////////////////////
+# 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
+
+ self._samples_per_symbol = samples_per_symbol
+ self._bt = bt
+
+ 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 =
Numeric.convolve(Numeric.array(self.gaussian_taps),Numeric.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)
+
+ # Define components from objects
+ self.define_component("nrz", self.nrz)
+ self.define_component("gaussian_filter", self.gaussian_filter)
+ self.define_component("fmmod", self.fmmod)
+
+ # Connect components
+ self.connect("self", 0, "nrz", 0)
+ self.connect("nrz", 0, "gaussian_filter", 0)
+ self.connect("gaussian_filter", 0, "fmmod", 0)
+ self.connect("fmmod", 0, "self", 0)
+
+ if verbose:
+ self._print_verbage()
+
+ if log:
+ self._setup_logging()
+
+ 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.define_component("nrz_dat", gr.file_sink(gr.sizeof_float,
"tx_nrz.dat"))
+ self.define_component("gaussian_filter_dat",
gr.file_sink(gr.sizeof_float, "tx_gaussian_filter.dat"))
+ self.define_component("fmmod_dat", gr.file_sink(gr.sizeof_gr_complex,
"tx_fmmod.dat"))
+
+ self.connect("nrz", 0, "nrz_dat", 0)
+ self.connect("gaussian_filter", 0, "gaussian_filter_dat", 0)
+ self.connect("fmmod", 0, "fmmod_dat", 0)
+
+ 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', 'fg'),
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_mod",
+ 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
+
+ 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)
+
+ 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 = gr.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 = gr.binary_slicer_fb()
+
+ # Define components from objects
+ self.define_component("fmdemod", self.fmdemod)
+ self.define_component("clock_recovery", self.clock_recovery)
+ self.define_component("slicer", self.slicer)
+
+ # Connect components
+ self.connect("self", 0, "fmdemod", 0)
+ self.connect("fmdemod", 0, "clock_recovery", 0)
+ self.connect("clock_recovery", 0, "slicer", 0)
+ self.connect("slicer", 0, "self", 0)
+
+ if verbose:
+ self._print_verbage()
+
+ if log:
+ self._setup_logging()
+
+ 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.define_component("fmdemod_dat", gr.file_sink(gr.sizeof_float,
"rx_fmdemod.dat"))
+ self.define_component("clock_recovery_dat",
gr.file_sink(gr.sizeof_float, "rx_clock_recovery.dat"))
+ self.define_component("slicer_dat", gr.file_sink(gr.sizeof_char,
"rx_slicer.dat"))
+
+ self.connect("fmdemod", 0, "fmdemod_dat", 0)
+ self.connect("clock_recovery", 0, "clock_recovery_dat", 0)
+ self.connect("slicer", 0, "slicer_dat", 0)
+
+ 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', 'fg'),
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)
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