def __init__(self, mode='VOR', zero_point=59, **kwargs):
self.channel_rate = channel_rate = 40000
internal_audio_rate = 20000 # TODO over spec'd
self.zero_point = zero_point
transition = 5000
SimpleAudioDemodulator.__init__(self,
mode=mode,
audio_rate=internal_audio_rate,
demod_rate=channel_rate,
band_filter=fm_subcarrier * 1.25 +
fm_deviation + transition / 2,
band_filter_transition=transition,
**kwargs)
self.dir_rate = dir_rate = 10
if internal_audio_rate % dir_rate != 0:
raise ValueError(
'Audio rate %s is not a multiple of direction-finding rate %s'
% (internal_audio_rate, dir_rate))
self.dir_scale = dir_scale = internal_audio_rate // dir_rate
self.audio_scale = audio_scale = channel_rate // internal_audio_rate
self.zeroer = blocks.add_const_vff((zero_point * (math.pi / 180), ))
self.dir_vector_filter = grfilter.fir_filter_ccf(
1, firdes.low_pass(1, dir_rate, 1, 2, firdes.WIN_HAMMING, 6.76))
self.am_channel_filter_block = grfilter.fir_filter_ccf(
1,
firdes.low_pass(1, channel_rate, 5000, 5000, firdes.WIN_HAMMING,
6.76))
self.goertzel_fm = fft.goertzel_fc(channel_rate,
dir_scale * audio_scale, 30)
self.goertzel_am = fft.goertzel_fc(internal_audio_rate, dir_scale, 30)
self.fm_channel_filter_block = grfilter.freq_xlating_fir_filter_ccc(
1, (firdes.low_pass(1.0, channel_rate, fm_subcarrier / 2,
fm_subcarrier / 2, firdes.WIN_HAMMING)),
fm_subcarrier, channel_rate)
self.multiply_conjugate_block = blocks.multiply_conjugate_cc(1)
self.complex_to_arg_block = blocks.complex_to_arg(1)
self.am_agc_block = analog.feedforward_agc_cc(1024, 1.0)
self.am_demod_block = analog.am_demod_cf(
channel_rate=channel_rate,
audio_decim=audio_scale,
audio_pass=5000,
audio_stop=5500,
)
self.fm_demod_block = analog.quadrature_demod_cf(1)
self.phase_agc_fm = analog.agc2_cc(1e-1, 1e-2, 1.0, 1.0)
self.phase_agc_am = analog.agc2_cc(1e-1, 1e-2, 1.0, 1.0)
self.probe = blocks.probe_signal_f()
self.audio_filter_block = grfilter.fir_filter_fff(
1, design_lofi_audio_filter(internal_audio_rate, False))
##################################################
# Connections
##################################################
# Input
self.connect(self, self.band_filter_block)
# AM chain
self.connect(self.band_filter_block, self.am_channel_filter_block,
self.am_agc_block, self.am_demod_block)
# AM audio
self.connect(
self.am_demod_block,
blocks.multiply_const_ff(1.0 / audio_modulation_index * 0.5),
self.audio_filter_block)
self.connect_audio_output(self.audio_filter_block)
# AM phase
self.connect(self.am_demod_block, self.goertzel_am, self.phase_agc_am,
(self.multiply_conjugate_block, 0))
# FM phase
self.connect(self.band_filter_block, self.fm_channel_filter_block,
self.fm_demod_block, self.goertzel_fm, self.phase_agc_fm,
(self.multiply_conjugate_block, 1))
# Phase comparison and output
self.connect(
self.multiply_conjugate_block,
self.dir_vector_filter,
self.complex_to_arg_block,
blocks.multiply_const_ff(-1), # opposite angle conventions
self.zeroer,
self.probe)
def __init__(self, mode='VOR', zero_point=59, **kwargs):
self.channel_rate = channel_rate = 40000
internal_audio_rate = 20000 # TODO over spec'd
self.zero_point = zero_point
transition = 5000
SimpleAudioDemodulator.__init__(self,
mode=mode,
audio_rate=internal_audio_rate,
demod_rate=channel_rate,
band_filter=fm_subcarrier * 1.25 + fm_deviation + transition / 2,
band_filter_transition=transition,
**kwargs)
self.dir_rate = dir_rate = 10
if internal_audio_rate % dir_rate != 0:
raise ValueError('Audio rate %s is not a multiple of direction-finding rate %s' % (internal_audio_rate, dir_rate))
self.dir_scale = dir_scale = internal_audio_rate // dir_rate
self.audio_scale = audio_scale = channel_rate // internal_audio_rate
self.zeroer = blocks.add_const_vff((zero_point * (math.pi / 180), ))
self.dir_vector_filter = grfilter.fir_filter_ccf(1, firdes.low_pass(
1, dir_rate, 1, 2, firdes.WIN_HAMMING, 6.76))
self.am_channel_filter_block = grfilter.fir_filter_ccf(1, firdes.low_pass(
1, channel_rate, 5000, 5000, firdes.WIN_HAMMING, 6.76))
self.goertzel_fm = fft.goertzel_fc(channel_rate, dir_scale * audio_scale, 30)
self.goertzel_am = fft.goertzel_fc(internal_audio_rate, dir_scale, 30)
self.fm_channel_filter_block = grfilter.freq_xlating_fir_filter_ccc(1, (firdes.low_pass(1.0, channel_rate, fm_subcarrier / 2, fm_subcarrier / 2, firdes.WIN_HAMMING)), fm_subcarrier, channel_rate)
self.multiply_conjugate_block = blocks.multiply_conjugate_cc(1)
self.complex_to_arg_block = blocks.complex_to_arg(1)
self.am_agc_block = analog.feedforward_agc_cc(1024, 1.0)
self.am_demod_block = analog.am_demod_cf(
channel_rate=channel_rate,
audio_decim=audio_scale,
audio_pass=5000,
audio_stop=5500,
)
self.fm_demod_block = analog.quadrature_demod_cf(1)
self.phase_agc_fm = analog.agc2_cc(1e-1, 1e-2, 1.0, 1.0)
self.phase_agc_am = analog.agc2_cc(1e-1, 1e-2, 1.0, 1.0)
self.probe = blocks.probe_signal_f()
self.audio_filter_block = grfilter.fir_filter_fff(1, design_lofi_audio_filter(internal_audio_rate, False))
##################################################
# Connections
##################################################
# Input
self.connect(
self,
self.band_filter_block)
# AM chain
self.connect(
self.band_filter_block,
self.am_channel_filter_block,
self.am_agc_block,
self.am_demod_block)
# AM audio
self.connect(
self.am_demod_block,
blocks.multiply_const_ff(1.0 / audio_modulation_index * 0.5),
self.audio_filter_block)
self.connect_audio_output(self.audio_filter_block)
# AM phase
self.connect(
self.am_demod_block,
self.goertzel_am,
self.phase_agc_am,
(self.multiply_conjugate_block, 0))
# FM phase
self.connect(
self.band_filter_block,
self.fm_channel_filter_block,
self.fm_demod_block,
self.goertzel_fm,
self.phase_agc_fm,
(self.multiply_conjugate_block, 1))
# Phase comparison and output
self.connect(
self.multiply_conjugate_block,
self.dir_vector_filter,
self.complex_to_arg_block,
blocks.multiply_const_ff(-1), # opposite angle conventions
self.zeroer,
self.probe)