def __init__(self, sps, channel_decim, channel_taps, options, usrp_rate, channel_rate, lo_freq):
gr.hier_block2.__init__(self, "rx_channel_cqpsk",
gr.io_signature(1, 1, gr.sizeof_gr_complex),
gr.io_signature(1, 1, gr.sizeof_float))
chan = gr.freq_xlating_fir_filter_ccf(int(channel_decim), channel_taps, lo_freq, usrp_rate)
agc = gr.feedforward_agc_cc(16, 1.0)
gain_omega = 0.125 * options.gain_mu * options.gain_mu
alpha = options.costas_alpha
beta = 0.125 * alpha * alpha
fmin = -0.025
fmax = 0.025
clock = repeater.gardner_costas_cc(sps, options.gain_mu, gain_omega, alpha, beta, fmax, fmin)
# Perform Differential decoding on the constellation
diffdec = gr.diff_phasor_cc()
# take angle of the difference (in radians)
to_float = gr.complex_to_arg()
# convert from radians such that signal is in -3/-1/+1/+3
rescale = gr.multiply_const_ff( (1 / (pi / 4)) )
self.connect (self, chan, agc, clock, diffdec, to_float, rescale, self)
def test_diff_phasor_cc (self):
src_data = (0+0j, 1+0j, -1+0j, 3+4j, -3-4j, -3+4j)
expected_result = (0+0j, 0+0j, -1+0j, -3-4j, -25+0j, -7-24j)
src = gr.vector_source_c (src_data)
op = gr.diff_phasor_cc ()
dst = gr.vector_sink_c ()
self.tb.connect (src, op)
self.tb.connect (op, dst)
self.tb.run () # run the graph and wait for it to finish
actual_result = dst.data () # fetch the contents of the sink
self.assertComplexTuplesAlmostEqual (expected_result, actual_result)
def __init__(self,
samples_per_symbol=_def_samples_per_symbol,
excess_bw=_def_excess_bw,
costas_alpha=_def_costas_alpha,
timing_alpha=_def_timing_alpha,
timing_max_dev=_def_timing_max_dev,
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 timing_alpha: timing loop alpha gain
@type timing_alpha: float
@param timing_max: timing loop maximum rate deviations
@type timing_max: 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, "dqpsk2_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._excess_bw = excess_bw
self._costas_alpha = costas_alpha
self._timing_alpha = timing_alpha
self._timing_beta = _def_timing_beta
self._timing_max_dev=timing_max_dev
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
self.agc = gr.agc2_cc(0.6e-1, 1e-3, 1, 1, 100)
#self.agc = gr.feedforward_agc_cc(16, 2.0)
self._costas_beta = 0.25 * self._costas_alpha * self._costas_alpha
# Allow a frequency swing of +/- half of the sample rate
fmin = -0.5
fmax = 0.5
self.clock_recov = gr.costas_loop_cc(self._costas_alpha,
self._costas_beta,
fmax, fmin, arity)
# symbol timing recovery with RRC data filter
nfilts = 32
ntaps = 11 * samples_per_symbol*nfilts
taps = gr.firdes.root_raised_cosine(nfilts, nfilts, 1.0/float(self._samples_per_symbol), self._excess_bw, ntaps)
self.time_recov = gr.pfb_clock_sync_ccf(self._samples_per_symbol,
self._timing_alpha,
taps, nfilts, nfilts/2, self._timing_max_dev)
self.time_recov.set_beta(self._timing_beta)
# Perform Differential decoding on the constellation
self.diffdec = gr.diff_phasor_cc()
# find closest constellation point
rot = 1
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())
if verbose:
self._print_verbage()
if log:
self._setup_logging()
# Connect
self.connect(self, self.agc,
self.clock_recov,
self.time_recov,
self.diffdec, self.slicer, self.symbol_mapper, self.unpack, self)
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 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 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._mm_gain_mu = gain_mu
self._mm_mu = mu
self._mm_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.agc2_cc(0.6e-1, 1e-3, 1, 1, 100)
self.agc = gr.feedforward_agc_cc(16, 2.0)
# RRC data filter
ntaps = 11 * 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.interp_fir_filter_ccf(1, self.rrc_taps)
if not self._mm_gain_mu:
sbs_to_mm = {2: 0.050, 3: 0.075, 4: 0.11, 5: 0.125, 6: 0.15, 7: 0.15}
self._mm_gain_mu = sbs_to_mm[samples_per_symbol]
self._mm_omega = self._samples_per_symbol
self._mm_gain_omega = .25 * self._mm_gain_mu * self._mm_gain_mu
self._costas_beta = 0.25 * self._costas_alpha * self._costas_alpha
fmin = -0.025
fmax = 0.025
self.receiver=gr.mpsk_receiver_cc(arity, pi/4.0,
self._costas_alpha, self._costas_beta,
fmin, fmax,
self._mm_mu, self._mm_gain_mu,
self._mm_omega, self._mm_gain_omega,
self._mm_omega_relative_limit)
# Perform Differential decoding on the constellation
self.diffdec = gr.diff_phasor_cc()
# find closest constellation point
rot = 1
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())
if verbose:
self._print_verbage()
if log:
self._setup_logging()
# Connect & Initialize base class
self._fg.connect(self.pre_scaler, self.agc, self.rrc_filter, self.receiver,
self.diffdec, self.slicer, self.symbol_mapper, self.unpack)
gr.hier_block.__init__(self, self._fg, self.pre_scaler, self.unpack)
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 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 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, "dbpsk_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._excess_bw = excess_bw
self._costas_alpha = costas_alpha
self._mm_gain_mu = gain_mu
self._mm_mu = mu
self._mm_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, 2.0)
# RRC data filter
ntaps = 11 * 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.interp_fir_filter_ccf(1, self.rrc_taps)
# symbol clock recovery
if not self._mm_gain_mu:
self._mm_gain_mu = 0.1
self._mm_omega = self._samples_per_symbol
self._mm_gain_omega = .25 * self._mm_gain_mu * self._mm_gain_mu
self._costas_beta = 0.25 * self._costas_alpha * self._costas_alpha
fmin = -0.25
fmax = 0.25
self.receiver=gr.mpsk_receiver_cc(arity, 0,
self._costas_alpha, self._costas_beta,
fmin, fmax,
self._mm_mu, self._mm_gain_mu,
self._mm_omega, self._mm_gain_omega,
self._mm_omega_relative_limit)
# Do differential decoding based on phase change of symbols
self.diffdec = gr.diff_phasor_cc()
# find closest constellation point
rot = 1
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())
if verbose:
self._print_verbage()
if log:
self._setup_logging()
# Connect and Initialize base class
self.connect(self, self.agc, self.rrc_filter, self.receiver,
self.diffdec, self.slicer, self.symbol_mapper, self.unpack, self)
def __init__(self,
samples_per_symbol=_def_samples_per_symbol,
excess_bw=_def_excess_bw,
freq_alpha=_def_freq_alpha,
phase_alpha=_def_phase_alpha,
timing_alpha=_def_timing_alpha,
timing_max_dev=_def_timing_max_dev,
gray_code=_def_gray_code,
verbose=_def_verbose,
log=_def_log,
sync_out=False):
"""
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 freq_alpha: loop filter gain for frequency recovery
@type freq_alpha: float
@param phase_alpha: loop filter gain
@type phase_alphas: float
@param timing_alpha: timing loop alpha gain
@type timing_alpha: float
@param timing_max: timing loop maximum rate deviations
@type timing_max: 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: Print modualtion data to files?
@type log: bool
@param sync_out: Output a sync signal on :1?
@type sync_out: bool
"""
if sync_out:
io_sig_out = gr.io_signaturev(
2, 2, (gr.sizeof_char, gr.sizeof_gr_complex))
else:
io_sig_out = gr.io_signature(1, 1, gr.sizeof_char)
gr.hier_block2.__init__(
self,
"dqpsk2_demod",
gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
io_sig_out) # Output signature
self._samples_per_symbol = samples_per_symbol
self._excess_bw = excess_bw
self._freq_alpha = freq_alpha
self._freq_beta = 0.25 * self._freq_alpha**2
self._phase_alpha = phase_alpha
self._timing_alpha = timing_alpha
self._timing_beta = _def_timing_beta
self._timing_max_dev = timing_max_dev
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
self.agc = gr.agc2_cc(0.6e-1, 1e-3, 1, 1, 100)
#self.agc = gr.feedforward_agc_cc(16, 2.0)
# Frequency correction
self.freq_recov = gr.fll_band_edge_cc(
self._samples_per_symbol, self._excess_bw,
11 * int(self._samples_per_symbol), self._freq_alpha,
self._freq_beta)
# symbol timing recovery with RRC data filter
nfilts = 32
ntaps = 11 * int(samples_per_symbol * nfilts)
taps = gr.firdes.root_raised_cosine(
nfilts, nfilts, 1.0 / float(self._samples_per_symbol),
self._excess_bw, ntaps)
self.time_recov = gr.pfb_clock_sync_ccf(self._samples_per_symbol,
self._timing_alpha, taps,
nfilts, nfilts / 2,
self._timing_max_dev)
self.time_recov.set_beta(self._timing_beta)
# Perform phase / fine frequency correction
self._phase_beta = 0.25 * self._phase_alpha * self._phase_alpha
# Allow a frequency swing of +/- half of the sample rate
fmin = -0.5
fmax = 0.5
self.phase_recov = gr.costas_loop_cc(self._phase_alpha,
self._phase_beta, fmax, fmin,
arity)
# Perform Differential decoding on the constellation
self.diffdec = gr.diff_phasor_cc()
# find closest constellation point
rot = 1
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())
if verbose:
self._print_verbage()
if log:
self._setup_logging()
# Connect
self.connect(self, self.agc, self.freq_recov, self.time_recov,
self.phase_recov, self.diffdec, self.slicer,
self.symbol_mapper, self.unpack, self)
if sync_out: self.connect(self.time_recov, (self, 1))
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 CQPSK demodulation
The input is the complex modulated signal at baseband.
The output is a stream of floats in [ -3 / -1 / +1 / +3 ]
@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,
"cqpsk_demod",
gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
gr.io_signature(1, 1, gr.sizeof_float)) # Output signature
self._samples_per_symbol = samples_per_symbol
self._excess_bw = excess_bw
self._costas_alpha = costas_alpha
self._mm_gain_mu = gain_mu
self._mm_mu = mu
self._mm_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.agc2_cc(0.6e-1, 1e-3, 1, 1, 100)
self.agc = gr.feedforward_agc_cc(16, 2.0)
# RRC data filter
ntaps = 11 * 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.interp_fir_filter_ccf(1, self.rrc_taps)
if not self._mm_gain_mu:
sbs_to_mm = {
2: 0.050,
3: 0.075,
4: 0.11,
5: 0.125,
6: 0.15,
7: 0.15
}
self._mm_gain_mu = sbs_to_mm[samples_per_symbol]
self._mm_omega = self._samples_per_symbol
self._mm_gain_omega = .25 * self._mm_gain_mu * self._mm_gain_mu
self._costas_beta = 0.25 * self._costas_alpha * self._costas_alpha
fmin = -0.025
fmax = 0.025
self.receiver = gr.mpsk_receiver_cc(
arity, pi / 4.0, self._costas_alpha, self._costas_beta, fmin, fmax,
self._mm_mu, self._mm_gain_mu, self._mm_omega, self._mm_gain_omega,
self._mm_omega_relative_limit)
# Perform Differential decoding on the constellation
self.diffdec = gr.diff_phasor_cc()
# take angle of the difference (in radians)
self.to_float = gr.complex_to_arg()
# convert from radians such that signal is in -3/-1/+1/+3
self.rescale = gr.multiply_const_ff(1 / (pi / 4))
if verbose:
self._print_verbage()
if log:
self._setup_logging()
# Connect & Initialize base class
self.connect(self, self.pre_scaler, self.agc, self.rrc_filter,
self.receiver, self.diffdec, self.to_float, self.rescale,
self)
def __init__(self):
gr.top_block.__init__(self)
parser = OptionParser(option_class=eng_option)
parser.add_option("-1", "--one-channel", action="store_true", default=False, help="software synthesized Q channel")
parser.add_option("-c", "--calibration", type="eng_float", default=0, help="freq offset")
parser.add_option("-d", "--debug", action="store_true", default=False, help="allow time at init to attach gdb")
parser.add_option("-C", "--costas-alpha", type="eng_float", default=0.125, help="Costas alpha")
parser.add_option("-g", "--gain", type="eng_float", default=1.0)
parser.add_option("-i", "--input-file", type="string", default="in.dat", help="specify the input file")
parser.add_option("-I", "--imbe", action="store_true", default=False, help="output IMBE codewords")
parser.add_option("-L", "--low-pass", type="eng_float", default=6.5e3, help="low pass cut-off", metavar="Hz")
parser.add_option("-o", "--output-file", type="string", default="out.dat", help="specify the output file")
parser.add_option("-p", "--polarity", action="store_true", default=False, help="use reversed polarity")
parser.add_option("-s", "--sample-rate", type="int", default=96000, help="input sample rate")
parser.add_option("-t", "--tone-detect", action="store_true", default=False, help="use experimental tone detect algorithm")
parser.add_option("-v", "--verbose", action="store_true", default=False, help="additional output")
(options, args) = parser.parse_args()
sample_rate = options.sample_rate
symbol_rate = 4800
samples_per_symbol = sample_rate // symbol_rate
IN = gr.file_source(gr.sizeof_gr_complex, options.input_file)
if options.one_channel:
C2F = gr.complex_to_float()
F2C = gr.float_to_complex()
# osc./mixer for mixing signal down to approx. zero IF
LO = gr.sig_source_c (sample_rate, gr.GR_COS_WAVE, options.calibration, 1.0, 0)
MIXER = gr.multiply_cc()
# get signal into normalized range (-1.0 - +1.0)
# FIXME: add AGC
AMP = gr.multiply_const_cc(options.gain)
lpf_taps = gr.firdes.low_pass(1.0, sample_rate, options.low_pass, options.low_pass * 0.1, gr.firdes.WIN_HANN)
decim_amt = 1
if options.tone_detect:
if sample_rate != 96000:
print "warning, only 96K has been tested."
print "other rates may require theta to be reviewed/adjusted."
step_size = 7.5e-8
theta = -4 # optimum timing sampling point
cic_length = 48
DEMOD = repeater.tdetect_cc(samples_per_symbol, step_size, theta, cic_length)
else:
# decim by 2 to get 48k rate
samples_per_symbol /= 2 # for DECIM
sample_rate /= 2 # for DECIM
decim_amt = 2
# create Gardner/Costas loop
# the loop will not work if the sample levels aren't normalized (above)
timing_error_gain = 0.025 # loop error gain
gain_omega = 0.25 * timing_error_gain * timing_error_gain
alpha = options.costas_alpha
beta = 0.125 * alpha * alpha
fmin = -0.025 # fmin and fmax are in radians/s
fmax = 0.025
DEMOD = repeater.gardner_costas_cc(samples_per_symbol, timing_error_gain, gain_omega, alpha, beta, fmax, fmin)
DECIM = gr.fir_filter_ccf (decim_amt, lpf_taps)
# probably too much phase noise etc to attempt coherent demodulation
# so we use differential
DIFF = gr.diff_phasor_cc()
# take angle of the phase difference (in radians)
TOFLOAT = gr.complex_to_arg()
# convert from radians such that signal is in [-3, -1, +1, +3]
RESCALE = gr.multiply_const_ff(1 / (pi / 4.0))
# optional polarity reversal (should be unnec. - now autodetected)
p = 1.0
if options.polarity:
p = -1.0
POLARITY = gr.multiply_const_ff(p)
# hard decision at specified points
levels = [-2.0, 0.0, 2.0, 4.0 ]
SLICER = repeater.fsk4_slicer_fb(levels)
# assemble received frames and route to Wireshark via UDP
hostname = "127.0.0.1"
port = 23456
debug = 0
if options.verbose:
debug = 255
do_imbe = False
if options.imbe:
do_imbe = True
do_output = True # enable block's output stream
do_msgq = False # msgq output not yet implemented
msgq = gr.msg_queue(2)
DECODER = repeater.p25_frame_assembler(hostname, port, debug, do_imbe, do_output, do_msgq, msgq)
OUT = gr.file_sink(gr.sizeof_char, options.output_file)
if options.one_channel:
self.connect(IN, C2F, F2C, (MIXER, 0))
else:
self.connect(IN, (MIXER, 0))
self.connect(LO, (MIXER, 1))
self.connect(MIXER, AMP, DECIM, DEMOD, DIFF, TOFLOAT, RESCALE, POLARITY, SLICER, DECODER, OUT)
if options.debug:
print 'Ready for GDB to attach (pid = %d)' % (os.getpid(),)
raw_input("Press 'Enter' to continue...")
def __init__(self, principal_gui, options):
gr.hier_block2.__init__(
self,
"bpsk_demod",
gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
gr.io_signature(1, 1, gr.sizeof_gr_complex),
) # Output signature
# Enter the parameters of modulation
self._samples_per_symbol = options.samples_per_symbol
self._costas_alpha = _def_costas_alpha
self._excess_bw = _def_excess_bw
self.verbose = options.verbose
self._mm_gain_mu = _def_gain_mu
self._mm_mu = _def_mu
self._mm_omega_relative_limit = _def_omega_relative_limit
self._gray_code = _def_gray_code
if self._samples_per_symbol < 2:
raise TypeError, "samples_per_symbol must be >= 2, is %r" % (self._samples_per_symbol,)
arity = pow(2, self.bits_per_symbol())
# Automatic gain control
# self.agc = gr.agc2_cc(0.6e-1, 1e-3, 1, 1, 100)
self.agc = gr.agc_cc(1e-5, 1.0, 1.0, 1.0)
# self.agc = gr.feedforward_agc_cc(16, 2.0)
# 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
0.35, # excess bandwidth (roll-off factor)
ntaps,
)
self.rrc_filter = gr.interp_fir_filter_ccf(1, self.rrc_taps)
# symbol clock recovery
if not self._mm_gain_mu:
self._mm_gain_mu = 0.1
self._mm_omega = self._samples_per_symbol
self._mm_gain_omega = 0.25 * self._mm_gain_mu * self._mm_gain_mu
self._costas_beta = 0.25 * self._costas_alpha * self._costas_alpha
fmin = -0.25
fmax = 0.25
self._costas = gr.costas_loop_cc(
0.05, # PLL first order gain
0.00025, # PLL second order gain
0.05, # Max frequency offset rad/sample
-0.05, # Min frequency offset rad/sample
2,
) # BPSK
# Create a M&M bit synchronization retiming block
self._mm = gr.clock_recovery_mm_cc(
self._samples_per_symbol, # Initial samples/symbol
1e-06, # Second order gain
0.5, # Initial symbol phase
0.001, # First order gain
0.0001,
) # Maximum timing offset
# self.receiver_sync=gr.mpsk_receiver_cc(arity, 0,
# self._costas_alpha, self._costas_beta,
# fmin, fmax,
# self._mm_mu, self._mm_gain_mu,
# self._mm_omega, self._mm_gain_omega,
# self._mm_omega_relative_limit)
# Do differential decoding based on phase change of symbols
# This bloc allow to decode the stream
# self.descrambler = gr.descrambler_bb(0x8A, 0x7F, 7)
# find closest constellation point
# rot = 1
# 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())
if self.verbose:
self._print_verbage()
# Do differential decoding based on phase change of symbols
self.diffdec = gr.diff_phasor_cc()
# Connect and Initialize base class
self.connect(self, self.agc, self.rrc_filter, self._costas, self._mm, self)
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 CQPSK demodulation
The input is the complex modulated signal at baseband.
The output is a stream of floats in [ -3 / -1 / +1 / +3 ]
@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, "cqpsk_demod",
gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
gr.io_signature(1, 1, gr.sizeof_float)) # Output signature
self._samples_per_symbol = samples_per_symbol
self._excess_bw = excess_bw
self._costas_alpha = costas_alpha
self._mm_gain_mu = gain_mu
self._mm_mu = mu
self._mm_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.agc2_cc(0.6e-1, 1e-3, 1, 1, 100)
self.agc = gr.feedforward_agc_cc(16, 2.0)
# RRC data filter
ntaps = 11 * 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.interp_fir_filter_ccf(1, self.rrc_taps)
if not self._mm_gain_mu:
sbs_to_mm = {2: 0.050, 3: 0.075, 4: 0.11, 5: 0.125, 6: 0.15, 7: 0.15}
self._mm_gain_mu = sbs_to_mm[samples_per_symbol]
self._mm_omega = self._samples_per_symbol
self._mm_gain_omega = .25 * self._mm_gain_mu * self._mm_gain_mu
self._costas_beta = 0.25 * self._costas_alpha * self._costas_alpha
fmin = -0.025
fmax = 0.025
if not _def_has_gr_digital:
self.receiver=gr.mpsk_receiver_cc(arity, pi/4.0,
self._costas_alpha, self._costas_beta,
fmin, fmax,
self._mm_mu, self._mm_gain_mu,
self._mm_omega, self._mm_gain_omega,
self._mm_omega_relative_limit)
else:
self.receiver=digital.mpsk_receiver_cc(arity, pi/4.0,
2*pi/150,
fmin, fmax,
self._mm_mu, self._mm_gain_mu,
self._mm_omega, self._mm_gain_omega,
self._mm_omega_relative_limit)
self.receiver.set_alpha(self._costas_alpha)
self.receiver.set_beta(self._costas_beta)
# Perform Differential decoding on the constellation
self.diffdec = gr.diff_phasor_cc()
# take angle of the difference (in radians)
self.to_float = gr.complex_to_arg()
# convert from radians such that signal is in -3/-1/+1/+3
self.rescale = gr.multiply_const_ff( 1 / (pi / 4) )
if verbose:
self._print_verbage()
if log:
self._setup_logging()
# Connect & Initialize base class
self.connect(self, self.pre_scaler, self.agc, self.rrc_filter, self.receiver,
self.diffdec, self.to_float, self.rescale, self)