def __init__(self, constellation, differential, rotation): if constellation.arity() > 256: # If this becomes limiting some of the blocks should be generalised so # that they can work with shorts and ints as well as chars. raise ValueError("Constellation cannot contain more than 256 points.") gr.hier_block2.__init__(self, "mod_demod", gr.io_signature(1, 1, gr.sizeof_char), # Input signature gr.io_signature(1, 1, gr.sizeof_char)) # Output signature arity = constellation.arity() # TX self.constellation = constellation self.differential = differential self.blocks = [self] # We expect a stream of unpacked bits. # First step is to pack them. self.blocks.append(gr.unpacked_to_packed_bb(1, gr.GR_MSB_FIRST)) # Second step we unpack them such that we have k bits in each byte where # each constellation symbol hold k bits. self.blocks.append( gr.packed_to_unpacked_bb(self.constellation.bits_per_symbol(), gr.GR_MSB_FIRST)) # Apply any pre-differential coding # Gray-coding is done here if we're also using differential coding. if self.constellation.apply_pre_diff_code(): self.blocks.append(digital.map_bb(self.constellation.pre_diff_code())) # Differential encoding. if self.differential: self.blocks.append(digital.diff_encoder_bb(arity)) # Convert to constellation symbols. self.blocks.append(digital.chunks_to_symbols_bc(self.constellation.points(), self.constellation.dimensionality())) # CHANNEL # Channel just consists of a rotation to check differential coding. if rotation is not None: self.blocks.append(gr.multiply_const_cc(rotation)) # RX # Convert the constellation symbols back to binary values. self.blocks.append(digital.constellation_decoder_cb(self.constellation.base())) # Differential decoding. if self.differential: self.blocks.append(digital.diff_decoder_bb(arity)) # Decode any pre-differential coding. if self.constellation.apply_pre_diff_code(): self.blocks.append(digital.map_bb( mod_codes.invert_code(self.constellation.pre_diff_code()))) # unpack the k bit vector into a stream of bits self.blocks.append(gr.unpack_k_bits_bb( self.constellation.bits_per_symbol())) # connect to block output check_index = len(self.blocks) self.blocks = self.blocks[:check_index] self.blocks.append(self) self.connect(*self.blocks)
def helper(self, symbols): src_data = [0, 1, 2, 3, 0, 1, 2, 3] expected_data = map(lambda x: symbols[x], src_data) src = blocks.vector_source_b(src_data) op = digital.map_bb(symbols) dst = blocks.vector_sink_b() self.tb.connect(src, op, dst) self.tb.run() result_data = list(dst.data()) self.assertEqual(expected_data, result_data)
def __init__(self, constellation, differential=_def_differential, samples_per_symbol=_def_samples_per_symbol, pre_diff_code=True, excess_bw=_def_excess_bw, freq_bw=_def_freq_bw, timing_bw=_def_timing_bw, phase_bw=_def_phase_bw, verbose=_def_verbose, log=_def_log): gr.hier_block2.__init__( self, "generic_demod", gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature gr.io_signature(1, 1, gr.sizeof_char)) # Output signature self._constellation = constellation self._samples_per_symbol = samples_per_symbol self._excess_bw = excess_bw self._phase_bw = phase_bw self._freq_bw = freq_bw self._timing_bw = timing_bw self._timing_max_dev = _def_timing_max_dev self._differential = differential if self._samples_per_symbol < 2: raise TypeError, ("sbp must be >= 2, is %d" % self._samples_per_symbol) # Only apply a predifferential coding if the constellation also supports it. self.pre_diff_code = pre_diff_code and self._constellation.apply_pre_diff_code( ) arity = pow(2, self.bits_per_symbol()) nfilts = 32 ntaps = 11 * int(self._samples_per_symbol * nfilts) # Automatic gain control self.agc = analog.agc2_cc(0.6e-1, 1e-3, 1, 1) # Frequency correction fll_ntaps = 55 self.freq_recov = digital.fll_band_edge_cc(self._samples_per_symbol, self._excess_bw, fll_ntaps, self._freq_bw) # symbol timing recovery with RRC data filter taps = filter.firdes.root_raised_cosine( nfilts, nfilts * self._samples_per_symbol, 1.0, self._excess_bw, ntaps) self.time_recov = digital.pfb_clock_sync_ccf(self._samples_per_symbol, self._timing_bw, taps, nfilts, nfilts // 2, self._timing_max_dev) fmin = -0.25 fmax = 0.25 self.receiver = digital.constellation_receiver_cb( self._constellation.base(), self._phase_bw, fmin, fmax) # Do differential decoding based on phase change of symbols if differential: self.diffdec = digital.diff_decoder_bb(arity) if self.pre_diff_code: self.symbol_mapper = digital.map_bb( mod_codes.invert_code(self._constellation.pre_diff_code())) # unpack the k bit vector into a stream of bits self.unpack = blocks.unpack_k_bits_bb(self.bits_per_symbol()) if verbose: self._print_verbage() if log: self._setup_logging() # Connect and Initialize base class self._blocks = [ self, self.agc, self.freq_recov, self.time_recov, self.receiver ] if differential: self._blocks.append(self.diffdec) if self.pre_diff_code: self._blocks.append(self.symbol_mapper) self._blocks += [self.unpack, self] self.connect(*self._blocks)
def __init__(self, constellation, differential=_def_differential, samples_per_symbol=_def_samples_per_symbol, pre_diff_code=True, excess_bw=_def_excess_bw, verbose=_def_verbose, log=_def_log): gr.hier_block2.__init__( self, "generic_mod", gr.io_signature(1, 1, gr.sizeof_char), # Input signature gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature self._constellation = constellation self._samples_per_symbol = samples_per_symbol self._excess_bw = excess_bw self._differential = differential # Only apply a predifferential coding if the constellation also supports it. self.pre_diff_code = pre_diff_code and self._constellation.apply_pre_diff_code( ) if self._samples_per_symbol < 2: raise TypeError, ("sbp must be >= 2, is %f" % self._samples_per_symbol) arity = pow(2, self.bits_per_symbol()) # turn bytes into k-bit vectors self.bytes2chunks = \ blocks.packed_to_unpacked_bb(self.bits_per_symbol(), gr.GR_MSB_FIRST) if self.pre_diff_code: self.symbol_mapper = digital.map_bb( self._constellation.pre_diff_code()) if differential: self.diffenc = digital.diff_encoder_bb(arity) self.chunks2symbols = digital.chunks_to_symbols_bc( self._constellation.points()) # pulse shaping filter nfilts = 32 ntaps = nfilts * 11 * int( self._samples_per_symbol) # make nfilts filters of ntaps each self.rrc_taps = filter.firdes.root_raised_cosine( nfilts, # gain nfilts, # sampling rate based on 32 filters in resampler 1.0, # symbol rate self._excess_bw, # excess bandwidth (roll-off factor) ntaps) self.rrc_filter = filter.pfb_arb_resampler_ccf( self._samples_per_symbol, self.rrc_taps) # Connect self._blocks = [self, self.bytes2chunks] if self.pre_diff_code: self._blocks.append(self.symbol_mapper) if differential: self._blocks.append(self.diffenc) self._blocks += [self.chunks2symbols, self.rrc_filter, self] self.connect(*self._blocks) if verbose: self._print_verbage() if log: self._setup_logging()
def __init__(self, constellation, differential=_def_differential, samples_per_symbol=_def_samples_per_symbol, pre_diff_code=True, excess_bw=_def_excess_bw, freq_bw=_def_freq_bw, timing_bw=_def_timing_bw, phase_bw=_def_phase_bw, verbose=_def_verbose, log=_def_log): gr.hier_block2.__init__(self, "generic_demod", gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature gr.io_signature(1, 1, gr.sizeof_char)) # Output signature self._constellation = constellation self._samples_per_symbol = samples_per_symbol self._excess_bw = excess_bw self._phase_bw = phase_bw self._freq_bw = freq_bw self._timing_bw = timing_bw self._timing_max_dev= _def_timing_max_dev self._differential = differential if self._samples_per_symbol < 2: raise TypeError, ("sbp must be >= 2, is %d" % self._samples_per_symbol) # Only apply a predifferential coding if the constellation also supports it. self.pre_diff_code = pre_diff_code and self._constellation.apply_pre_diff_code() arity = pow(2,self.bits_per_symbol()) nfilts = 32 ntaps = 11 * int(self._samples_per_symbol*nfilts) # Automatic gain control self.agc = analog.agc2_cc(0.6e-1, 1e-3, 1, 1, 100) # Frequency correction fll_ntaps = 55 self.freq_recov = digital.fll_band_edge_cc(self._samples_per_symbol, self._excess_bw, fll_ntaps, self._freq_bw) # symbol timing recovery with RRC data filter taps = filter.firdes.root_raised_cosine(nfilts, nfilts*self._samples_per_symbol, 1.0, self._excess_bw, ntaps) self.time_recov = digital.pfb_clock_sync_ccf(self._samples_per_symbol, self._timing_bw, taps, nfilts, nfilts//2, self._timing_max_dev) fmin = -0.25 fmax = 0.25 self.receiver = digital.constellation_receiver_cb( self._constellation.base(), self._phase_bw, fmin, fmax) # Do differential decoding based on phase change of symbols if differential: self.diffdec = digital.diff_decoder_bb(arity) if self.pre_diff_code: self.symbol_mapper = digital.map_bb( mod_codes.invert_code(self._constellation.pre_diff_code())) # unpack the k bit vector into a stream of bits self.unpack = blocks.unpack_k_bits_bb(self.bits_per_symbol()) if verbose: self._print_verbage() if log: self._setup_logging() # Connect and Initialize base class self._blocks = [self, self.agc, self.freq_recov, self.time_recov, self.receiver] if differential: self._blocks.append(self.diffdec) if self.pre_diff_code: self._blocks.append(self.symbol_mapper) self._blocks += [self.unpack, self] self.connect(*self._blocks)
def __init__(self, constellation, differential=_def_differential, samples_per_symbol=_def_samples_per_symbol, pre_diff_code=True, excess_bw=_def_excess_bw, verbose=_def_verbose, log=_def_log): gr.hier_block2.__init__(self, "generic_mod", gr.io_signature(1, 1, gr.sizeof_char), # Input signature gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature self._constellation = constellation self._samples_per_symbol = samples_per_symbol self._excess_bw = excess_bw self._differential = differential # Only apply a predifferential coding if the constellation also supports it. self.pre_diff_code = pre_diff_code and self._constellation.apply_pre_diff_code() if self._samples_per_symbol < 2: raise TypeError, ("sbp must be >= 2, is %f" % self._samples_per_symbol) arity = pow(2,self.bits_per_symbol()) # turn bytes into k-bit vectors self.bytes2chunks = \ blocks.packed_to_unpacked_bb(self.bits_per_symbol(), gr.GR_MSB_FIRST) if self.pre_diff_code: self.symbol_mapper = digital.map_bb(self._constellation.pre_diff_code()) if differential: self.diffenc = digital.diff_encoder_bb(arity) self.chunks2symbols = digital.chunks_to_symbols_bc(self._constellation.points()) # pulse shaping filter nfilts = 32 ntaps = nfilts * 11 * int(self._samples_per_symbol) # make nfilts filters of ntaps each self.rrc_taps = filter.firdes.root_raised_cosine( nfilts, # gain nfilts, # sampling rate based on 32 filters in resampler 1.0, # symbol rate self._excess_bw, # excess bandwidth (roll-off factor) ntaps) self.rrc_filter = filter.pfb_arb_resampler_ccf(self._samples_per_symbol, self.rrc_taps) # Connect self._blocks = [self, self.bytes2chunks] if self.pre_diff_code: self._blocks.append(self.symbol_mapper) if differential: self._blocks.append(self.diffenc) self._blocks += [self.chunks2symbols, self.rrc_filter, self] self.connect(*self._blocks) if verbose: self._print_verbage() if log: self._setup_logging()
def __init__(self, constellation, differential, rotation): if constellation.arity() > 256: # If this becomes limiting some of the blocks should be generalised so # that they can work with shorts and ints as well as chars. raise ValueError( "Constellation cannot contain more than 256 points.") gr.hier_block2.__init__( self, "mod_demod", gr.io_signature(1, 1, gr.sizeof_char), # Input signature gr.io_signature(1, 1, gr.sizeof_char)) # Output signature arity = constellation.arity() # TX self.constellation = constellation self.differential = differential self.blocks = [self] # We expect a stream of unpacked bits. # First step is to pack them. self.blocks.append(blocks.unpacked_to_packed_bb(1, gr.GR_MSB_FIRST)) # Second step we unpack them such that we have k bits in each byte where # each constellation symbol hold k bits. self.blocks.append( blocks.packed_to_unpacked_bb(self.constellation.bits_per_symbol(), gr.GR_MSB_FIRST)) # Apply any pre-differential coding # Gray-coding is done here if we're also using differential coding. if self.constellation.apply_pre_diff_code(): self.blocks.append( digital.map_bb(self.constellation.pre_diff_code())) # Differential encoding. if self.differential: self.blocks.append(digital.diff_encoder_bb(arity)) # Convert to constellation symbols. self.blocks.append( digital.chunks_to_symbols_bc(self.constellation.points(), self.constellation.dimensionality())) # CHANNEL # Channel just consists of a rotation to check differential coding. if rotation is not None: self.blocks.append(blocks.multiply_const_cc(rotation)) # RX # Convert the constellation symbols back to binary values. self.blocks.append( digital.constellation_decoder_cb(self.constellation.base())) # Differential decoding. if self.differential: self.blocks.append(digital.diff_decoder_bb(arity)) # Decode any pre-differential coding. if self.constellation.apply_pre_diff_code(): self.blocks.append( digital.map_bb( mod_codes.invert_code(self.constellation.pre_diff_code()))) # unpack the k bit vector into a stream of bits self.blocks.append( blocks.unpack_k_bits_bb(self.constellation.bits_per_symbol())) # connect to block output check_index = len(self.blocks) self.blocks = self.blocks[:check_index] self.blocks.append(self) self.connect(*self.blocks)
def __init__(self, constellation, samples_per_symbol=_def_samples_per_symbol, differential=_def_differential, excess_bw=_def_excess_bw, gray_coded=True, verbose=_def_verbose, log=_def_log): """ Hierarchical block for RRC-filtered differential generic modulation. The input is a byte stream (unsigned char) and the output is the complex modulated signal at baseband. @param constellation: determines the modulation type @type constellation: gnuradio.digital.gr_constellation @param samples_per_symbol: samples per baud >= 2 @type samples_per_symbol: float @param excess_bw: Root-raised cosine filter excess bandwidth @type excess_bw: float @param gray_coded: turn gray coding on/off @type gray_coded: bool @param verbose: Print information about modulator? @type verbose: bool @param log: Log modulation data to files? @type log: bool """ gr.hier_block2.__init__(self, "generic_mod", gr.io_signature(1, 1, gr.sizeof_char), # Input signature gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature self._constellation = constellation.base() self._samples_per_symbol = samples_per_symbol self._excess_bw = excess_bw self._differential = differential if self._samples_per_symbol < 2: raise TypeError, ("sbp must be >= 2, is %f" % 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 gray_coded == True: self.symbol_mapper = digital.map_bb(self._constellation.pre_diff_code()) if differential: self.diffenc = digital.diff_encoder_bb(arity) self.chunks2symbols = digital.chunks_to_symbols_bc(self._constellation.points()) # pulse shaping filter nfilts = 32 ntaps = nfilts * 11 * int(self._samples_per_symbol) # make nfilts filters of ntaps each self.rrc_taps = gr.firdes.root_raised_cosine( nfilts, # gain nfilts, # sampling rate based on 32 filters in resampler 1.0, # symbol rate self._excess_bw, # excess bandwidth (roll-off factor) ntaps) self.rrc_filter = gr.pfb_arb_resampler_ccf(self._samples_per_symbol, self.rrc_taps) # Connect blocks = [self, self.bytes2chunks] if gray_coded == True: blocks.append(self.symbol_mapper) if differential: blocks.append(self.diffenc) blocks += [self.chunks2symbols, self.rrc_filter, self] self.connect(*blocks) if verbose: self._print_verbage() if log: self._setup_logging()
def __init__(self, constellation, samples_per_symbol=_def_samples_per_symbol, differential=_def_differential, excess_bw=_def_excess_bw, gray_coded=True, freq_bw=_def_freq_bw, timing_bw=_def_timing_bw, phase_bw=_def_phase_bw, verbose=_def_verbose, log=_def_log): """ Hierarchical block for RRC-filtered differential generic demodulation. The input is the complex modulated signal at baseband. The output is a stream of bits packed 1 bit per byte (LSB) @param constellation: determines the modulation type @type constellation: gnuradio.digital.gr_constellation @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 gray_coded: turn gray coding on/off @type gray_coded: bool @param freq_bw: loop filter lock-in bandwidth @type freq_bw: float @param timing_bw: timing recovery loop lock-in bandwidth @type timing_bw: float @param phase_bw: phase recovery loop bandwidth @type phase_bw: 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, "generic_demod", gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature gr.io_signature(1, 1, gr.sizeof_char)) # Output signature self._constellation = constellation.base() self._samples_per_symbol = samples_per_symbol self._excess_bw = excess_bw self._phase_bw = phase_bw self._freq_bw = freq_bw self._timing_bw = timing_bw self._timing_max_dev= _def_timing_max_dev self._differential = differential if self._samples_per_symbol < 2: raise TypeError, ("sbp must be >= 2, is %d" % self._samples_per_symbol) arity = pow(2,self.bits_per_symbol()) nfilts = 32 ntaps = 11 * int(self._samples_per_symbol*nfilts) # Automatic gain control self.agc = gr.agc2_cc(0.6e-1, 1e-3, 1, 1, 100) # Frequency correction fll_ntaps = 55 self.freq_recov = digital.fll_band_edge_cc(self._samples_per_symbol, self._excess_bw, fll_ntaps, self._freq_bw) # symbol timing recovery with RRC data filter taps = gr.firdes.root_raised_cosine(nfilts, nfilts*self._samples_per_symbol, 1.0, self._excess_bw, ntaps) self.time_recov = digital.pfb_clock_sync_ccf(self._samples_per_symbol, self._timing_bw, taps, nfilts, nfilts//2, self._timing_max_dev) fmin = -0.25 fmax = 0.25 self.receiver = digital.constellation_receiver_cb( self._constellation, self._phase_bw, fmin, fmax) # Do differential decoding based on phase change of symbols if differential: self.diffdec = digital.diff_decoder_bb(arity) if gray_coded: self.symbol_mapper = digital.map_bb( mod_codes.invert_code(self._constellation.pre_diff_code())) # 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 blocks = [self, self.agc, self.freq_recov, self.time_recov, self.receiver] if differential: blocks.append(self.diffdec) if self._constellation.apply_pre_diff_code(): blocks.append(self.symbol_mapper) blocks += [self.unpack, self] self.connect(*blocks)
def __init__(self, constellation, samples_per_symbol=_def_samples_per_symbol, differential=_def_differential, excess_bw=_def_excess_bw, gray_coded=True, verbose=_def_verbose, log=_def_log): """ Hierarchical block for RRC-filtered differential generic modulation. The input is a byte stream (unsigned char) and the output is the complex modulated signal at baseband. @param constellation: determines the modulation type @type constellation: gnuradio.digital.gr_constellation @param samples_per_symbol: samples per baud >= 2 @type samples_per_symbol: float @param excess_bw: Root-raised cosine filter excess bandwidth @type excess_bw: float @param gray_coded: turn gray coding on/off @type gray_coded: bool @param verbose: Print information about modulator? @type verbose: bool @param log: Log modulation data to files? @type log: bool """ gr.hier_block2.__init__( self, "generic_mod", gr.io_signature(1, 1, gr.sizeof_char), # Input signature gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature self._constellation = constellation.base() self._samples_per_symbol = samples_per_symbol self._excess_bw = excess_bw self._differential = differential if self._samples_per_symbol < 2: raise TypeError, ("sbp must be >= 2, is %f" % 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 gray_coded == True: self.symbol_mapper = digital.map_bb( self._constellation.pre_diff_code()) if differential: self.diffenc = digital.diff_encoder_bb(arity) self.chunks2symbols = digital.chunks_to_symbols_bc( self._constellation.points()) # pulse shaping filter nfilts = 32 ntaps = nfilts * 11 * int( self._samples_per_symbol) # make nfilts filters of ntaps each self.rrc_taps = gr.firdes.root_raised_cosine( nfilts, # gain nfilts, # sampling rate based on 32 filters in resampler 1.0, # symbol rate self._excess_bw, # excess bandwidth (roll-off factor) ntaps) self.rrc_filter = gr.pfb_arb_resampler_ccf(self._samples_per_symbol, self.rrc_taps) # Connect blocks = [self, self.bytes2chunks] if gray_coded == True: blocks.append(self.symbol_mapper) if differential: blocks.append(self.diffenc) blocks += [self.chunks2symbols, self.rrc_filter, self] self.connect(*blocks) if verbose: self._print_verbage() if log: self._setup_logging()
def __init__(self, constellation, samples_per_symbol=_def_samples_per_symbol, differential=_def_differential, excess_bw=_def_excess_bw, gray_coded=True, freq_bw=_def_freq_bw, timing_bw=_def_timing_bw, phase_bw=_def_phase_bw, verbose=_def_verbose, log=_def_log): """ Hierarchical block for RRC-filtered differential generic demodulation. The input is the complex modulated signal at baseband. The output is a stream of bits packed 1 bit per byte (LSB) @param constellation: determines the modulation type @type constellation: gnuradio.digital.gr_constellation @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 gray_coded: turn gray coding on/off @type gray_coded: bool @param freq_bw: loop filter lock-in bandwidth @type freq_bw: float @param timing_bw: timing recovery loop lock-in bandwidth @type timing_bw: float @param phase_bw: phase recovery loop bandwidth @type phase_bw: 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, "generic_demod", gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature gr.io_signature(1, 1, gr.sizeof_char)) # Output signature self._constellation = constellation.base() self._samples_per_symbol = samples_per_symbol self._excess_bw = excess_bw self._phase_bw = phase_bw self._freq_bw = freq_bw self._timing_bw = timing_bw self._timing_max_dev = _def_timing_max_dev self._differential = differential if self._samples_per_symbol < 2: raise TypeError, ("sbp must be >= 2, is %d" % self._samples_per_symbol) arity = pow(2, self.bits_per_symbol()) nfilts = 32 ntaps = 11 * int(self._samples_per_symbol * nfilts) # Automatic gain control self.agc = gr.agc2_cc(0.6e-1, 1e-3, 1, 1, 100) # Frequency correction fll_ntaps = 55 self.freq_recov = digital.fll_band_edge_cc(self._samples_per_symbol, self._excess_bw, fll_ntaps, self._freq_bw) # symbol timing recovery with RRC data filter taps = gr.firdes.root_raised_cosine(nfilts, nfilts * self._samples_per_symbol, 1.0, self._excess_bw, ntaps) self.time_recov = digital.pfb_clock_sync_ccf(self._samples_per_symbol, self._timing_bw, taps, nfilts, nfilts // 2, self._timing_max_dev) fmin = -0.25 fmax = 0.25 self.receiver = digital.constellation_receiver_cb( self._constellation, self._phase_bw, fmin, fmax) # Do differential decoding based on phase change of symbols if differential: self.diffdec = digital.diff_decoder_bb(arity) if gray_coded: self.symbol_mapper = digital.map_bb( mod_codes.invert_code(self._constellation.pre_diff_code())) # 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 blocks = [ self, self.agc, self.freq_recov, self.time_recov, self.receiver ] if differential: blocks.append(self.diffdec) if self._constellation.apply_pre_diff_code(): blocks.append(self.symbol_mapper) blocks += [self.unpack, self] self.connect(*blocks)