def __init__(self,
if_rate=None,
filter_type=None,
excess_bw=_def_excess_bw,
symbol_rate=_def_symbol_rate):
"""
Hierarchical block for P25 demodulation base class
@param if_rate: sample rate of complex input channel
@type if_rate: int
"""
self.if_rate = if_rate
self.symbol_rate = symbol_rate
self.bb_sink = None
self.null_sink = blocks.null_sink(gr.sizeof_float)
self.baseband_amp = blocks.multiply_const_ff(_def_bb_gain)
coeffs = op25_c4fm_mod.c4fm_taps(
sample_rate=self.if_rate,
span=9,
generator=op25_c4fm_mod.transfer_function_rx).generate()
sps = self.if_rate / 4800
if filter_type == 'rrc':
ntaps = 7 * sps
if ntaps & 1 == 0:
ntaps += 1
coeffs = filter.firdes.root_raised_cosine(1.0, if_rate,
symbol_rate, excess_bw,
ntaps)
if filter_type == 'gmsk':
# lifted from gmsk.py
_omega = sps
_gain_mu = _def_gmsk_mu
_mu = _def_mu
if not _gain_mu:
_gain_mu = 0.175
_gain_omega = .25 * _gain_mu * _gain_mu # critically damped
self.symbol_filter = blocks.multiply_const_ff(1.0)
self.fsk4_demod = digital.clock_recovery_mm_ff(
_omega, _gain_omega, _mu, _gain_mu, _def_omega_relative_limit)
self.slicer = digital.binary_slicer_fb()
elif filter_type == 'fsk4mm':
self.symbol_filter = filter.fir_filter_fff(1, coeffs)
_omega = sps
_gain_mu = _def_gmsk_mu
_mu = _def_mu
if not _gain_mu:
_gain_mu = 0.0175
_gain_omega = .25 * _gain_mu * _gain_mu # critically damped
self.fsk4_demod = digital.clock_recovery_mm_ff(
_omega, _gain_omega, _mu, _gain_mu, _def_omega_relative_limit)
levels = [-2.0, 0.0, 2.0, 4.0]
self.slicer = op25_repeater.fsk4_slicer_fb(levels)
else:
self.symbol_filter = filter.fir_filter_fff(1, coeffs)
autotuneq = gr.msg_queue(2)
self.fsk4_demod = op25.fsk4_demod_ff(autotuneq, self.if_rate,
self.symbol_rate)
levels = [-2.0, 0.0, 2.0, 4.0]
self.slicer = op25_repeater.fsk4_slicer_fb(levels)
def __init__(self,
if_rate=None,
filter_type=None,
excess_bw=_def_excess_bw,
symbol_rate=_def_symbol_rate):
"""
Hierarchical block for P25 demodulation base class
@param if_rate: sample rate of complex input channel
@type if_rate: int
"""
self.if_rate = if_rate
self.symbol_rate = symbol_rate
self.bb_sink = None
self.baseband_amp = blocks.multiply_const_ff(_def_bb_gain)
coeffs = op25_c4fm_mod.c4fm_taps(
sample_rate=self.if_rate,
span=9,
generator=op25_c4fm_mod.transfer_function_rx).generate()
if filter_type == 'rrc':
sps = self.if_rate / 4800
ntaps = 7 * sps
if ntaps & 1 == 0:
ntaps += 1
coeffs = filter.firdes.root_raised_cosine(1.0, if_rate,
symbol_rate, excess_bw,
ntaps)
self.symbol_filter = filter.fir_filter_fff(1, coeffs)
autotuneq = gr.msg_queue(2)
self.fsk4_demod = op25.fsk4_demod_ff(autotuneq, self.if_rate,
self.symbol_rate)
levels = [-2.0, 0.0, 2.0, 4.0]
self.slicer = op25_repeater.fsk4_slicer_fb(levels)
def __init__(self,
threshold1=-2,
threshold2=0,
threshold3=2.0,
threshold4=4.0):
gr.hier_block2.__init__(
self,
"Symbol Demapper",
gr.io_signature(1, 1, gr.sizeof_float * 1),
gr.io_signature(1, 1, gr.sizeof_char * 1),
)
##################################################
# Parameters
##################################################
self.threshold1 = threshold1
self.threshold2 = threshold2
self.threshold3 = threshold3
self.threshold4 = threshold4
##################################################
# Blocks
##################################################
self.op25_fsk4_slicer_fb_0 = op25_repeater.fsk4_slicer_fb(
[-2.0, 0.0, 2.0, 4.0])
##################################################
# Connections
##################################################
self.connect((self.op25_fsk4_slicer_fb_0, 0), (self, 0))
self.connect((self, 0), (self.op25_fsk4_slicer_fb_0, 0))
def __init__(self,
if_rate = None,
symbol_rate = _def_symbol_rate):
"""
Hierarchical block for P25 demodulation base class
@param if_rate: sample rate of complex input channel
@type if_rate: int
"""
self.if_rate = if_rate
self.symbol_rate = symbol_rate
self.bb_sink = None
self.baseband_amp = blocks.multiply_const_ff(_def_bb_gain)
coeffs = op25_c4fm_mod.c4fm_taps(sample_rate=self.if_rate, span=9, generator=op25_c4fm_mod.transfer_function_rx).generate()
self.symbol_filter = filter.fir_filter_fff(1, coeffs)
autotuneq = gr.msg_queue(2)
self.fsk4_demod = op25.fsk4_demod_ff(autotuneq, self.if_rate, self.symbol_rate)
levels = [ -2.0, 0.0, 2.0, 4.0 ]
self.slicer = op25_repeater.fsk4_slicer_fb(levels)
def __init__(self,
if_rate = None,
symbol_rate = _def_symbol_rate):
"""
Hierarchical block for P25 demodulation base class
@param if_rate: sample rate of complex input channel
@type if_rate: int
"""
self.if_rate = if_rate
self.symbol_rate = symbol_rate
self.bb_sink = None
self.baseband_amp = blocks.multiply_const_ff(_def_bb_gain)
coeffs = op25_c4fm_mod.c4fm_taps(sample_rate=self.if_rate, span=9, generator=op25_c4fm_mod.transfer_function_rx).generate()
self.symbol_filter = filter.fir_filter_fff(1, coeffs)
autotuneq = gr.msg_queue(2)
self.fsk4_demod = op25.fsk4_demod_ff(autotuneq, self.if_rate, self.symbol_rate)
levels = [ -2.0, 0.0, 2.0, 4.0 ]
self.slicer = op25_repeater.fsk4_slicer_fb(levels)
def __init__(self,
input_rate=None,
demod_type='cqpsk',
relative_freq=0,
offset=0,
if_rate=_def_if_rate,
gain_mu=_def_gain_mu,
costas_alpha=_def_costas_alpha,
symbol_rate=_def_symbol_rate):
"""
Hierarchical block for P25 demodulation.
The complex input is tuned, decimated and demodulated
@param input_rate: sample rate of complex input channel
@type input_rate: int
"""
gr.hier_block2.__init__(
self,
"p25_demod_cb",
gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
gr.io_signature(1, 1, gr.sizeof_char)) # Output signature
# gr.io_signature(0, 0, 0)) # Output signature
p25_demod_base.__init__(self, if_rate=if_rate, symbol_rate=symbol_rate)
self.input_rate = input_rate
self.if_rate = if_rate
self.symbol_rate = symbol_rate
self.connect_state = None
self.offset = 0
self.sps = 0.0
self.lo_freq = 0
self.float_sink = None
self.complex_sink = None
# local osc
self.lo = analog.sig_source_c(input_rate, analog.GR_SIN_WAVE, 0, 1.0,
0)
self.mixer = blocks.multiply_cc()
lpf_coeffs = filter.firdes.low_pass(1.0, input_rate, 7250, 725,
filter.firdes.WIN_HANN)
decimation = int(input_rate / if_rate)
self.lpf = filter.fir_filter_ccf(decimation, lpf_coeffs)
resampled_rate = float(input_rate) / float(
decimation) # rate at output of self.lpf
self.arb_resampler = filter.pfb.arb_resampler_ccf(
float(self.if_rate) / resampled_rate)
self.connect(self, (self.mixer, 0))
self.connect(self.lo, (self.mixer, 1))
self.connect(self.mixer, self.lpf, self.arb_resampler)
levels = [-2.0, 0.0, 2.0, 4.0]
self.slicer = op25_repeater.fsk4_slicer_fb(levels)
omega = float(self.if_rate) / float(self.symbol_rate)
gain_omega = 0.1 * gain_mu * gain_mu
alpha = costas_alpha
beta = 0.125 * alpha * alpha
fmax = 2400 # Hz
fmax = 2 * pi * fmax / float(self.if_rate)
self.clock = op25_repeater.gardner_costas_cc(omega, gain_mu,
gain_omega, alpha, beta,
fmax, -fmax)
self.agc = analog.feedforward_agc_cc(16, 1.0)
# Perform Differential decoding on the constellation
self.diffdec = digital.diff_phasor_cc()
# take angle of the difference (in radians)
self.to_float = blocks.complex_to_arg()
# convert from radians such that signal is in -3/-1/+1/+3
self.rescale = blocks.multiply_const_ff((1 / (pi / 4)))
# fm demodulator (needed in fsk4 case)
fm_demod_gain = if_rate / (2.0 * pi * _def_symbol_deviation)
self.fm_demod = analog.quadrature_demod_cf(fm_demod_gain)
self.connect_chain(demod_type)
self.connect(self.slicer, self)
self.set_relative_frequency(relative_freq)
def __init__(self,
input_rate = None,
demod_type = 'cqpsk',
relative_freq = 0,
offset = 0,
if_rate = _def_if_rate,
gain_mu = _def_gain_mu,
costas_alpha = _def_costas_alpha,
symbol_rate = _def_symbol_rate):
"""
Hierarchical block for P25 demodulation.
The complex input is tuned, decimated and demodulated
@param input_rate: sample rate of complex input channel
@type input_rate: int
"""
gr.hier_block2.__init__(self, "p25_demod_cb",
gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
gr.io_signature(1, 1, gr.sizeof_char)) # Output signature
# gr.io_signature(0, 0, 0)) # Output signature
p25_demod_base.__init__(self, if_rate=if_rate, symbol_rate=symbol_rate)
self.input_rate = input_rate
self.if_rate = if_rate
self.symbol_rate = symbol_rate
self.connect_state = None
self.offset = 0
self.sps = 0.0
self.lo_freq = 0
self.float_sink = None
self.complex_sink = None
# local osc
self.lo = analog.sig_source_c (input_rate, analog.GR_SIN_WAVE, 0, 1.0, 0)
self.mixer = blocks.multiply_cc()
lpf_coeffs = filter.firdes.low_pass(1.0, input_rate, 7250, 725, filter.firdes.WIN_HANN)
decimation = int(input_rate / if_rate)
self.lpf = filter.fir_filter_ccf(decimation, lpf_coeffs)
resampled_rate = float(input_rate) / float(decimation) # rate at output of self.lpf
self.arb_resampler = filter.pfb.arb_resampler_ccf(
float(self.if_rate) / resampled_rate)
self.connect(self, (self.mixer, 0))
self.connect(self.lo, (self.mixer, 1))
self.connect(self.mixer, self.lpf, self.arb_resampler)
levels = [ -2.0, 0.0, 2.0, 4.0 ]
self.slicer = op25_repeater.fsk4_slicer_fb(levels)
omega = float(self.if_rate) / float(self.symbol_rate)
gain_omega = 0.1 * gain_mu * gain_mu
alpha = costas_alpha
beta = 0.125 * alpha * alpha
fmax = 2400 # Hz
fmax = 2*pi * fmax / float(self.if_rate)
self.clock = op25_repeater.gardner_costas_cc(omega, gain_mu, gain_omega, alpha, beta, fmax, -fmax)
self.agc = analog.feedforward_agc_cc(16, 1.0)
# Perform Differential decoding on the constellation
self.diffdec = digital.diff_phasor_cc()
# take angle of the difference (in radians)
self.to_float = blocks.complex_to_arg()
# convert from radians such that signal is in -3/-1/+1/+3
self.rescale = blocks.multiply_const_ff( (1 / (pi / 4)) )
# fm demodulator (needed in fsk4 case)
fm_demod_gain = if_rate / (2.0 * pi * _def_symbol_deviation)
self.fm_demod = analog.quadrature_demod_cf(fm_demod_gain)
self.connect_chain(demod_type)
self.connect(self.slicer, self)
self.set_relative_frequency(relative_freq)
def __init__(self,
if_rate = None,
filter_type = None,
excess_bw = _def_excess_bw,
symbol_rate = _def_symbol_rate):
"""
Hierarchical block for P25 demodulation base class
@param if_rate: sample rate of complex input channel
@type if_rate: int
"""
self.if_rate = if_rate
self.symbol_rate = symbol_rate
self.bb_sink = {}
self.bb_tuner_sink = {}
self.spiir = filter.single_pole_iir_filter_ff(0.0001)
self.null_sink = blocks.null_sink(gr.sizeof_float)
self.baseband_amp = blocks.multiply_const_ff(_def_bb_gain)
coeffs = op25_c4fm_mod.c4fm_taps(sample_rate=self.if_rate, span=9, generator=op25_c4fm_mod.transfer_function_rx).generate()
sps = self.if_rate // self.symbol_rate
if filter_type == 'rrc':
ntaps = 7 * sps
if ntaps & 1 == 0:
ntaps += 1
coeffs = filter.firdes.root_raised_cosine(1.0, self.if_rate, self.symbol_rate, excess_bw, ntaps)
if filter_type == 'nxdn':
coeffs = op25_c4fm_mod.c4fm_taps(sample_rate=self.if_rate, span=9, generator=op25_c4fm_mod.transfer_function_nxdn, symbol_rate=self.symbol_rate).generate()
gain_adj = 1.8 # for nxdn48 6.25 KHz
if self.symbol_rate == 4800:
gain_adj = 0.77 # nxdn96 12.5 KHz
coeffs = [x * gain_adj for x in coeffs]
if filter_type == 'gmsk':
# lifted from gmsk.py
_omega = sps
_gain_mu = _def_gmsk_mu
_mu = _def_mu
if not _gain_mu:
_gain_mu = 0.175
_gain_omega = .25 * _gain_mu * _gain_mu # critically damped
self.symbol_filter = blocks.multiply_const_ff(1.0)
self.fsk4_demod = digital.clock_recovery_mm_ff(_omega, _gain_omega,
_mu, _gain_mu,
_def_omega_relative_limit)
self.slicer = digital.binary_slicer_fb()
elif filter_type == 'fsk4mm':
self.symbol_filter = filter.fir_filter_fff(1, coeffs)
_omega = sps
_gain_mu = _def_gmsk_mu
_mu = _def_mu
if not _gain_mu:
_gain_mu = 0.0175
_gain_omega = .25 * _gain_mu * _gain_mu # critically damped
self.fsk4_demod = digital.clock_recovery_mm_ff(_omega, _gain_omega,
_mu, _gain_mu,
_def_omega_relative_limit)
levels = [ -2.0, 0.0, 2.0, 4.0 ]
self.slicer = op25_repeater.fsk4_slicer_fb(levels)
elif filter_type == 'fsk2mm':
ntaps = 7 * sps
if ntaps & 1 == 0:
ntaps += 1
coeffs = filter.firdes.root_raised_cosine(1.0, self.if_rate, self.symbol_rate, excess_bw, ntaps)
self.fsk4_demod = digital.clock_recovery_mm_ff(sps, 0.1, 0.5, 0.05, 0.005)
self.baseband_amp = op25_repeater.rmsagc_ff(alpha=0.01, k=1.0)
self.symbol_filter = filter.fir_filter_fff(1, coeffs)
self.slicer = digital.binary_slicer_fb()
elif filter_type == 'fsk2':
ntaps = 7 * sps
if ntaps & 1 == 0:
ntaps += 1
coeffs = filter.firdes.root_raised_cosine(1.0, self.if_rate, self.symbol_rate, excess_bw, ntaps)
autotuneq = gr.msg_queue(2)
self.fsk4_demod = op25.fsk4_demod_ff(autotuneq, self.if_rate, self.symbol_rate, True)
self.baseband_amp = op25_repeater.rmsagc_ff(alpha=0.01, k=1.0)
self.symbol_filter = filter.fir_filter_fff(1, coeffs)
self.slicer = digital.binary_slicer_fb()
elif filter_type == "widepulse":
coeffs = op25_c4fm_mod.c4fm_taps(sample_rate=self.if_rate, span=9, generator=op25_c4fm_mod.transfer_function_rx).generate(rate_multiplier = 2.0)
self.symbol_filter = filter.fir_filter_fff(1, coeffs)
autotuneq = gr.msg_queue(2)
self.fsk4_demod = op25.fsk4_demod_ff(autotuneq, self.if_rate, self.symbol_rate)
levels = [ -2.0, 0.0, 2.0, 4.0 ]
self.slicer = op25_repeater.fsk4_slicer_fb(levels)
else:
self.symbol_filter = filter.fir_filter_fff(1, coeffs)
autotuneq = gr.msg_queue(2)
self.fsk4_demod = op25.fsk4_demod_ff(autotuneq, self.if_rate, self.symbol_rate)
levels = [ -2.0, 0.0, 2.0, 4.0 ]
self.slicer = op25_repeater.fsk4_slicer_fb(levels)
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("-a",
"--agc",
action="store_true",
default=False,
help="automatic gain control (overrides --gain)")
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("-r",
"--raw-symbols",
type="string",
default=None,
help="dump decoded symbols to file")
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")
parser.add_option("-6",
"--k6k",
action="store_true",
default=False,
help="use 6K symbol rate")
(options, args) = parser.parse_args()
sample_rate = options.sample_rate
if options.k6k:
symbol_rate = 6000
else:
symbol_rate = 4800
samples_per_symbol = sample_rate // symbol_rate
IN = blocks.file_source(gr.sizeof_gr_complex, options.input_file)
if options.one_channel:
C2F = blocks.complex_to_float()
F2C = blocks.float_to_complex()
# osc./mixer for mixing signal down to approx. zero IF
LO = analog.sig_source_c(sample_rate, analog.GR_COS_WAVE,
options.calibration, 1.0, 0)
MIXER = blocks.multiply_cc()
# get signal into normalized range (-1.0 - +1.0)
if options.agc:
AMP = analog.feedforward_agc_cc(16, 1.0)
else:
AMP = blocks.multiply_const_cc(options.gain)
lpf_taps = filter.firdes.low_pass(1.0, sample_rate, options.low_pass,
options.low_pass * 0.1,
filter.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 = op25_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 = op25_repeater.gardner_costas_cc(samples_per_symbol,
timing_error_gain,
gain_omega, alpha, beta,
fmax, fmin)
DECIM = filter.fir_filter_ccf(decim_amt, lpf_taps)
# probably too much phase noise etc to attempt coherent demodulation
# so we use differential
DIFF = digital.diff_phasor_cc()
# take angle of the phase difference (in radians)
TOFLOAT = blocks.complex_to_arg()
# convert from radians such that signal is in [-3, -1, +1, +3]
RESCALE = blocks.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 = blocks.multiply_const_ff(p)
# hard decision at specified points
levels = [-2.0, 0.0, 2.0, 4.0]
SLICER = op25_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 = op25_repeater.p25_frame_assembler(hostname, port, debug,
do_imbe, do_output,
do_msgq, msgq, False,
False)
OUT = blocks.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.raw_symbols:
SINKC = blocks.file_sink(gr.sizeof_char, options.raw_symbols)
self.connect(SLICER, SINKC)
if options.debug:
print 'Ready for GDB to attach (pid = %d)' % (os.getpid(), )
raw_input("Press 'Enter' to continue...")
def __init__(self,
input_rate=None,
demod_type='cqpsk',
filter_type=None,
excess_bw=_def_excess_bw,
relative_freq=0,
offset=0,
if_rate=_def_if_rate,
gain_mu=_def_gain_mu,
costas_alpha=_def_costas_alpha,
symbol_rate=_def_symbol_rate):
"""
Hierarchical block for P25 demodulation.
The complex input is tuned, decimated and demodulated
@param input_rate: sample rate of complex input channel
@type input_rate: int
"""
gr.hier_block2.__init__(
self,
"p25_demod_cb",
gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
gr.io_signature(1, 1, gr.sizeof_char)) # Output signature
# gr.io_signature(0, 0, 0)) # Output signature
p25_demod_base.__init__(self,
if_rate=if_rate,
symbol_rate=symbol_rate,
filter_type=filter_type)
self.input_rate = input_rate
self.if_rate = if_rate
self.symbol_rate = symbol_rate
self.connect_state = None
self.offset = 0
self.sps = 0.0
self.lo_freq = 0
self.float_sink = None
self.complex_sink = None
self.if1 = 0
self.if2 = 0
self.t_cache = {}
if filter_type == 'rrc':
self.set_baseband_gain(0.61)
# local osc
self.lo = analog.sig_source_c(input_rate, analog.GR_SIN_WAVE, 0, 1.0,
0)
self.mixer = blocks.multiply_cc()
decimator_values = get_decim(input_rate)
if decimator_values:
self.decim, self.decim2 = decimator_values
self.if1 = input_rate / self.decim
self.if2 = self.if1 / self.decim2
sys.stderr.write(
'Using two-stage decimator for speed=%d, decim=%d/%d if1=%d if2=%d\n'
% (input_rate, self.decim, self.decim2, self.if1, self.if2))
bpf_coeffs = filter.firdes.complex_band_pass(
1.0, input_rate, -self.if1 / 2, self.if1 / 2, self.if1 / 2,
filter.firdes.WIN_HAMMING)
self.t_cache[0] = bpf_coeffs
fa = 6250
fb = self.if2 / 2
lpf_coeffs = filter.firdes.low_pass(1.0, self.if1, (fb + fa) / 2,
fb - fa,
filter.firdes.WIN_HAMMING)
self.bpf = filter.fir_filter_ccc(self.decim, bpf_coeffs)
self.lpf = filter.fir_filter_ccf(self.decim2, lpf_coeffs)
resampled_rate = self.if2
self.bfo = analog.sig_source_c(self.if1, analog.GR_SIN_WAVE, 0,
1.0, 0)
self.connect(self, self.bpf, (self.mixer, 0))
self.connect(self.bfo, (self.mixer, 1))
else:
sys.stderr.write(
'Unable to use two-stage decimator for speed=%d\n' %
(input_rate))
# local osc
self.lo = analog.sig_source_c(input_rate, analog.GR_SIN_WAVE, 0,
1.0, 0)
lpf_coeffs = filter.firdes.low_pass(1.0, input_rate, 7250, 1450,
filter.firdes.WIN_HANN)
decimation = int(input_rate / if_rate)
self.lpf = filter.fir_filter_ccf(decimation, lpf_coeffs)
resampled_rate = float(input_rate) / float(
decimation) # rate at output of self.lpf
self.connect(self, (self.mixer, 0))
self.connect(self.lo, (self.mixer, 1))
self.connect(self.mixer, self.lpf)
if self.if_rate != resampled_rate:
self.if_out = filter.pfb.arb_resampler_ccf(
float(self.if_rate) / resampled_rate)
self.connect(self.lpf, self.if_out)
else:
self.if_out = self.lpf
fa = 6250
fb = fa + 625
cutoff_coeffs = filter.firdes.low_pass(1.0, self.if_rate,
(fb + fa) / 2, fb - fa,
filter.firdes.WIN_HANN)
self.cutoff = filter.fir_filter_ccf(1, cutoff_coeffs)
levels = [-2.0, 0.0, 2.0, 4.0]
self.slicer = op25_repeater.fsk4_slicer_fb(levels)
omega = float(self.if_rate) / float(self.symbol_rate)
gain_omega = 0.1 * gain_mu * gain_mu
alpha = costas_alpha
beta = 0.125 * alpha * alpha
fmax = 2400 # Hz
fmax = 2 * pi * fmax / float(self.if_rate)
self.clock = op25_repeater.gardner_costas_cc(omega, gain_mu,
gain_omega, alpha, beta,
fmax, -fmax)
self.agc = analog.feedforward_agc_cc(16, 1.0)
# Perform Differential decoding on the constellation
self.diffdec = digital.diff_phasor_cc()
# take angle of the difference (in radians)
self.to_float = blocks.complex_to_arg()
# convert from radians such that signal is in -3/-1/+1/+3
self.rescale = blocks.multiply_const_ff((1 / (pi / 4)))
# fm demodulator (needed in fsk4 case)
fm_demod_gain = if_rate / (2.0 * pi * _def_symbol_deviation)
self.fm_demod = analog.quadrature_demod_cf(fm_demod_gain)
self.connect_chain(demod_type)
self.connect(self.slicer, self)
self.set_relative_frequency(relative_freq)
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("-a", "--agc", action="store_true", default=False, help="automatic gain control (overrides --gain)")
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("-r", "--raw-symbols", type="string", default=None, help="dump decoded symbols to file")
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")
parser.add_option("-6", "--k6k", action="store_true", default=False, help="use 6K symbol rate")
(options, args) = parser.parse_args()
sample_rate = options.sample_rate
if options.k6k:
symbol_rate = 6000
else:
symbol_rate = 4800
samples_per_symbol = sample_rate // symbol_rate
IN = blocks.file_source(gr.sizeof_gr_complex, options.input_file)
if options.one_channel:
C2F = blocks.complex_to_float()
F2C = blocks.float_to_complex()
# osc./mixer for mixing signal down to approx. zero IF
LO = analog.sig_source_c (sample_rate, analog.GR_COS_WAVE, options.calibration, 1.0, 0)
MIXER = blocks.multiply_cc()
# get signal into normalized range (-1.0 - +1.0)
if options.agc:
AMP = analog.feedforward_agc_cc(16, 1.0)
else:
AMP = blocks.multiply_const_cc(options.gain)
lpf_taps = filter.firdes.low_pass(1.0, sample_rate, options.low_pass, options.low_pass * 0.1, filter.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 = op25_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 = op25_repeater.gardner_costas_cc(samples_per_symbol, timing_error_gain, gain_omega, alpha, beta, fmax, fmin)
DECIM = filter.fir_filter_ccf (decim_amt, lpf_taps)
# probably too much phase noise etc to attempt coherent demodulation
# so we use differential
DIFF = digital.diff_phasor_cc()
# take angle of the phase difference (in radians)
TOFLOAT = blocks.complex_to_arg()
# convert from radians such that signal is in [-3, -1, +1, +3]
RESCALE = blocks.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 = blocks.multiply_const_ff(p)
# hard decision at specified points
levels = [-2.0, 0.0, 2.0, 4.0 ]
SLICER = op25_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 = op25_repeater.p25_frame_assembler(hostname, port, debug, do_imbe, do_output, do_msgq, msgq, False, False)
OUT = blocks.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.raw_symbols:
SINKC = blocks.file_sink(gr.sizeof_char, options.raw_symbols)
self.connect(SLICER, SINKC)
if options.debug:
print 'Ready for GDB to attach (pid = %d)' % (os.getpid(),)
raw_input("Press 'Enter' to continue...")
