+++ /dev/null
-#
-# 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 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/gmsk2 for examples
-
-"""
-differential BPSK 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 = 0.03
-_def_mu = 0.05
-_def_omega_relative_limit = 0.005
-
-
-# /////////////////////////////////////////////////////////////////////////////
-# DBPSK modulator
-# /////////////////////////////////////////////////////////////////////////////
-
-class dbpsk_mod(gr.hier_block):
-
- def __init__(self, fg,
- 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 differential BPSK modulation.
-
- The input is a byte stream (unsigned char) and the
- output is the complex modulated signal at baseband.
-
- @param fg: flow graph
- @type fg: flow graph
- @param samples_per_symbol: samples per baud >= 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 log: Log modulation data to files?
- @type log: bool
- """
-
- self._fg = fg
- self._samples_per_symbol = samples_per_symbol
- self._excess_bw = excess_bw
- self._gray_code = gray_code
-
- if not isinstance(self._samples_per_symbol, int) or self._samples_per_symbol < 2:
- raise TypeError, ("sbp must be an integer >= 2, is %d" % self._samples_per_symbol)
-
- ntaps = 11 * self._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)
-
- self.chunks2symbols = gr.chunks_to_symbols_bc(psk.constellation[arity])
-
- # pulse shaping filter
- self.rrc_taps = gr.firdes.root_raised_cosine(
- self._samples_per_symbol, # gain (samples_per_symbol since we're
- # interpolating by samples_per_symbol)
- 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)
-
- # Connect
- fg.connect(self.bytes2chunks, self.symbol_mapper, self.diffenc,
- self.chunks2symbols, self.rrc_filter)
-
- if verbose:
- self._print_verbage()
-
- if log:
- self._setup_logging()
-
- # Initialize base class
- gr.hier_block.__init__(self, self._fg, self.bytes2chunks, self.rrc_filter)
-
- def samples_per_symbol(self):
- return self._samples_per_symbol
-
- def bits_per_symbol(self=None): # static method that's also callable on an instance
- return 1
- bits_per_symbol = staticmethod(bits_per_symbol) # make it a static method. RTFM
-
- def add_options(parser):
- """
- Adds DBPSK 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]")
- parser.add_option("", "--no-gray-code", dest="gray_code",
- action="store_false", default=True,
- 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(dbpsk_mod.__init__,
- ('self', 'fg'), options)
- extract_kwargs_from_options=staticmethod(extract_kwargs_from_options)
-
-
- 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
-
- def _setup_logging(self):
- print "Modulation logging turned on."
- self._fg.connect(self.bytes2chunks,
- gr.file_sink(gr.sizeof_char, "bytes2chunks.dat"))
- self._fg.connect(self.symbol_mapper,
- gr.file_sink(gr.sizeof_char, "graycoder.dat"))
- self._fg.connect(self.diffenc,
- gr.file_sink(gr.sizeof_char, "diffenc.dat"))
- self._fg.connect(self.chunks2symbols,
- gr.file_sink(gr.sizeof_gr_complex, "chunks2symbols.dat"))
- self._fg.connect(self.rrc_filter,
- gr.file_sink(gr.sizeof_gr_complex, "rrc_filter.dat"))
-
-
-# /////////////////////////////////////////////////////////////////////////////
-# DBPSK demodulator
-#
-# Differentially coherent detection of differentially encoded BPSK
-# /////////////////////////////////////////////////////////////////////////////
-
-class dbpsk_demod(gr.hier_block):
-
- def __init__(self, fg,
- 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 differential BPSK demodulation
-
- The input is the complex modulated signal at baseband.
- The output is a stream of bits packed 1 bit per byte (LSB)
-
- @param fg: flow graph
- @type fg: flow graph
- @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
- """
-
- self._fg = fg
- 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, "samples_per_symbol must be >= 2, is %r" % (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.agc2_cc(0.6e-1, 1e-3, 1, 1, 100)
- self.agc = gr.feedforward_agc_cc(16, 1.0)
-
-
- # Costas loop (carrier tracking)
- # The Costas loop is not needed for BPSK, though it can help. Turn the Costas loop on
- # by setting an alpha value not None.
- if self._costas_alpha is not None:
- costas_order = 2
- beta = .25 * self._costas_alpha * self._costas_alpha
- self.costas_loop = gr.costas_loop_cc(self._costas_alpha, beta, 0.002, -0.002, costas_order)
-
- # RRC data filter
- ntaps = 11 * self._samples_per_symbol
- self.rrc_taps = gr.firdes.root_raised_cosine(
- 1.0, # 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)
-
- # find closest constellation point
- rot = 1
- rotated_const = map(lambda pt: pt * rot, psk.constellation[arity])
- #print "rotated_const =", rotated_const
-
- self.diffdec = gr.diff_phasor_cc()
- #self.diffdec = gr.diff_decoder_bb(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())
-
- if verbose:
- self._print_verbage()
-
- if log:
- self._setup_logging()
-
- # Connect and Initialize base class
- if self._costas_alpha is not None: # With Costas Loop
- self._fg.connect(self.pre_scaler, self.agc, self.costas_loop,
- self.rrc_filter, self.clock_recovery, self.diffdec,
- self.slicer, self.symbol_mapper, self.unpack)
- else: # Without Costas Loop
- self._fg.connect(self.pre_scaler, self.agc,
- self.rrc_filter, self.clock_recovery, self.diffdec,
- self.slicer, self.symbol_mapper, self.unpack)
-
- gr.hier_block.__init__(self, self._fg, self.pre_scaler, self.unpack)
-
- 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. 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
- if self._costas_alpha is not None:
- print "Costas Loop alpha = %.5f" % self._costas_alpha
- else:
- print "Costas Loop is turned off"
- 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 "Modulation logging turned on."
- self._fg.connect(self.pre_scaler,
- gr.file_sink(gr.sizeof_gr_complex, "prescaler.dat"))
- self._fg.connect(self.agc,
- gr.file_sink(gr.sizeof_gr_complex, "agc.dat"))
- if self._costas_alpha is not None:
- self._fg.connect(self.costas_loop,
- gr.file_sink(gr.sizeof_gr_complex, "costas_loop.dat"))
- self._fg.connect((self.costas_loop,1),
- gr.file_sink(gr.sizeof_gr_complex, "costas_error.dat"))
- self._fg.connect(self.rrc_filter,
- gr.file_sink(gr.sizeof_gr_complex, "rrc_filter.dat"))
- self._fg.connect(self.clock_recovery,
- gr.file_sink(gr.sizeof_gr_complex, "clock_recovery.dat"))
- self._fg.connect((self.clock_recovery,1),
- gr.file_sink(gr.sizeof_gr_complex, "clock_recovery_error.dat"))
- self._fg.connect(self.diffdec,
- gr.file_sink(gr.sizeof_gr_complex, "diffdec.dat"))
- self._fg.connect(self.slicer,
- gr.file_sink(gr.sizeof_char, "slicer.dat"))
- self._fg.connect(self.symbol_mapper,
- gr.file_sink(gr.sizeof_char, "symbol_mapper.dat"))
- self._fg.connect(self.unpack,
- gr.file_sink(gr.sizeof_char, "unpack.dat"))
-
- def add_options(parser):
- """
- Adds DBPSK demodulation-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] (GMSK/PSK)")
- parser.add_option("", "--mu", type="float", default=_def_mu,
- help="set M&M symbol sync loop mu value [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)")
- 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(
- dbpsk_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('dbpsk', dbpsk_mod)
-modulation_utils.add_type_1_demod('dbpsk', dbpsk_demod)
projects / debian / gnuradio / blobdiff