def __init__(self):
grc_wxgui.top_block_gui.__init__(self, title="Rds Tx")
_icon_path = "/home/azimout/.local/share/icons/hicolor/32x32/apps/gnuradio-grc.png"
self.SetIcon(wx.Icon(_icon_path, wx.BITMAP_TYPE_ANY))
##################################################
# Variables
##################################################
self.usrp_interp = usrp_interp = 500
self.dac_rate = dac_rate = 128e6
self.wav_rate = wav_rate = 44100
self.usrp_rate = usrp_rate = int(dac_rate/usrp_interp)
self.fm_max_dev = fm_max_dev = 120e3
##################################################
# Blocks
##################################################
self.band_pass_filter_0 = gr.interp_fir_filter_fff(1, firdes.band_pass(
1, usrp_rate, 54e3, 60e3, 3e3, firdes.WIN_HAMMING, 6.76))
self.band_pass_filter_1 = gr.interp_fir_filter_fff(1, firdes.band_pass(
1, usrp_rate, 23e3, 53e3, 2e3, firdes.WIN_HAMMING, 6.76))
self.blks2_rational_resampler_xxx_1 = blks2.rational_resampler_fff(
interpolation=usrp_rate,
decimation=wav_rate,
taps=None,
fractional_bw=None,
)
self.blks2_rational_resampler_xxx_1_0 = blks2.rational_resampler_fff(
interpolation=usrp_rate,
decimation=wav_rate,
taps=None,
fractional_bw=None,
)
self.gr_add_xx_0 = gr.add_vff(1)
self.gr_add_xx_1 = gr.add_vff(1)
self.gr_char_to_float_0 = gr.char_to_float()
self.gr_diff_encoder_bb_0 = gr.diff_encoder_bb(2)
self.gr_frequency_modulator_fc_0 = gr.frequency_modulator_fc(2*math.pi*fm_max_dev/usrp_rate)
self.gr_map_bb_0 = gr.map_bb(([-1,1]))
self.gr_map_bb_1 = gr.map_bb(([1,2]))
self.gr_multiply_xx_0 = gr.multiply_vff(1)
self.gr_multiply_xx_1 = gr.multiply_vff(1)
self.gr_rds_data_encoder_0 = rds.data_encoder("/media/dimitris/mywork/gr/dimitris/rds/trunk/src/test/rds_data.xml")
self.gr_rds_rate_enforcer_0 = rds.rate_enforcer(256000)
self.gr_sig_source_x_0 = gr.sig_source_f(usrp_rate, gr.GR_COS_WAVE, 19e3, 0.3, 0)
self.gr_sub_xx_0 = gr.sub_ff(1)
self.gr_unpack_k_bits_bb_0 = gr.unpack_k_bits_bb(2)
self.gr_wavfile_source_0 = gr.wavfile_source("/media/dimitris/mywork/gr/dimitris/rds/trunk/src/python/limmenso_stereo.wav", True)
self.low_pass_filter_0 = gr.interp_fir_filter_fff(1, firdes.low_pass(
1, usrp_rate, 1.5e3, 2e3, firdes.WIN_HAMMING, 6.76))
self.low_pass_filter_0_0 = gr.interp_fir_filter_fff(1, firdes.low_pass(
1, usrp_rate, 15e3, 2e3, firdes.WIN_HAMMING, 6.76))
self.usrp_simple_sink_x_0 = grc_usrp.simple_sink_c(which=0, side="A")
self.usrp_simple_sink_x_0.set_interp_rate(500)
self.usrp_simple_sink_x_0.set_frequency(107.2e6, verbose=True)
self.usrp_simple_sink_x_0.set_gain(0)
self.usrp_simple_sink_x_0.set_enable(True)
self.usrp_simple_sink_x_0.set_auto_tr(True)
self.wxgui_fftsink2_0 = fftsink2.fft_sink_f(
self.GetWin(),
baseband_freq=0,
y_per_div=20,
y_divs=10,
ref_level=0,
ref_scale=2.0,
sample_rate=usrp_rate,
fft_size=1024,
fft_rate=30,
average=False,
avg_alpha=None,
title="FFT Plot",
peak_hold=False,
)
self.Add(self.wxgui_fftsink2_0.win)
##################################################
# Connections
##################################################
self.connect((self.gr_sig_source_x_0, 0), (self.gr_rds_rate_enforcer_0, 1))
self.connect((self.gr_char_to_float_0, 0), (self.gr_rds_rate_enforcer_0, 0))
self.connect((self.gr_map_bb_0, 0), (self.gr_char_to_float_0, 0))
self.connect((self.gr_frequency_modulator_fc_0, 0), (self.usrp_simple_sink_x_0, 0))
self.connect((self.gr_add_xx_1, 0), (self.gr_frequency_modulator_fc_0, 0))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_add_xx_1, 1))
self.connect((self.gr_sub_xx_0, 0), (self.gr_multiply_xx_1, 2))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_multiply_xx_1, 1))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_multiply_xx_1, 0))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_multiply_xx_0, 3))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_multiply_xx_0, 2))
self.connect((self.blks2_rational_resampler_xxx_1_0, 0), (self.gr_add_xx_0, 1))
self.connect((self.blks2_rational_resampler_xxx_1, 0), (self.gr_add_xx_0, 0))
self.connect((self.blks2_rational_resampler_xxx_1_0, 0), (self.gr_sub_xx_0, 1))
self.connect((self.blks2_rational_resampler_xxx_1, 0), (self.gr_sub_xx_0, 0))
self.connect((self.gr_wavfile_source_0, 1), (self.blks2_rational_resampler_xxx_1_0, 0))
self.connect((self.gr_wavfile_source_0, 0), (self.blks2_rational_resampler_xxx_1, 0))
self.connect((self.gr_rds_data_encoder_0, 0), (self.gr_diff_encoder_bb_0, 0))
self.connect((self.gr_diff_encoder_bb_0, 0), (self.gr_map_bb_1, 0))
self.connect((self.gr_map_bb_1, 0), (self.gr_unpack_k_bits_bb_0, 0))
self.connect((self.gr_unpack_k_bits_bb_0, 0), (self.gr_map_bb_0, 0))
self.connect((self.gr_rds_rate_enforcer_0, 0), (self.low_pass_filter_0, 0))
self.connect((self.low_pass_filter_0, 0), (self.gr_multiply_xx_0, 0))
self.connect((self.gr_multiply_xx_0, 0), (self.band_pass_filter_0, 0))
self.connect((self.band_pass_filter_0, 0), (self.gr_add_xx_1, 0))
self.connect((self.gr_multiply_xx_1, 0), (self.band_pass_filter_1, 0))
self.connect((self.band_pass_filter_1, 0), (self.gr_add_xx_1, 3))
self.connect((self.gr_add_xx_1, 0), (self.wxgui_fftsink2_0, 0))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_multiply_xx_0, 1))
self.connect((self.gr_add_xx_0, 0), (self.low_pass_filter_0_0, 0))
self.connect((self.low_pass_filter_0_0, 0), (self.gr_add_xx_1, 2))
def __init__(self):
grc_wxgui.top_block_gui.__init__(self, title="Rds Tx")
_icon_path = "/home/azimout/.local/share/icons/hicolor/32x32/apps/gnuradio-grc.png"
self.SetIcon(wx.Icon(_icon_path, wx.BITMAP_TYPE_ANY))
##################################################
# Variables
##################################################
self.usrp_interp = usrp_interp = 500
self.dac_rate = dac_rate = 128e6
self.wav_rate = wav_rate = 44100
self.usrp_rate = usrp_rate = int(dac_rate / usrp_interp)
self.fm_max_dev = fm_max_dev = 120e3
##################################################
# Blocks
##################################################
self.band_pass_filter_0 = gr.interp_fir_filter_fff(
1,
firdes.band_pass(1, usrp_rate, 54e3, 60e3, 3e3, firdes.WIN_HAMMING,
6.76))
self.band_pass_filter_1 = gr.interp_fir_filter_fff(
1,
firdes.band_pass(1, usrp_rate, 23e3, 53e3, 2e3, firdes.WIN_HAMMING,
6.76))
self.blks2_rational_resampler_xxx_1 = blks2.rational_resampler_fff(
interpolation=usrp_rate,
decimation=wav_rate,
taps=None,
fractional_bw=None,
)
self.blks2_rational_resampler_xxx_1_0 = blks2.rational_resampler_fff(
interpolation=usrp_rate,
decimation=wav_rate,
taps=None,
fractional_bw=None,
)
self.gr_add_xx_0 = gr.add_vff(1)
self.gr_add_xx_1 = gr.add_vff(1)
self.gr_char_to_float_0 = gr.char_to_float()
self.gr_diff_encoder_bb_0 = gr.diff_encoder_bb(2)
self.gr_frequency_modulator_fc_0 = gr.frequency_modulator_fc(
2 * math.pi * fm_max_dev / usrp_rate)
self.gr_map_bb_0 = gr.map_bb(([-1, 1]))
self.gr_map_bb_1 = gr.map_bb(([1, 2]))
self.gr_multiply_xx_0 = gr.multiply_vff(1)
self.gr_multiply_xx_1 = gr.multiply_vff(1)
self.gr_rds_data_encoder_0 = rds.data_encoder(
"/media/dimitris/mywork/gr/dimitris/rds/trunk/src/test/rds_data.xml"
)
self.gr_rds_rate_enforcer_0 = rds.rate_enforcer(256000)
self.gr_sig_source_x_0 = gr.sig_source_f(usrp_rate, gr.GR_COS_WAVE,
19e3, 0.3, 0)
self.gr_sub_xx_0 = gr.sub_ff(1)
self.gr_unpack_k_bits_bb_0 = gr.unpack_k_bits_bb(2)
self.gr_wavfile_source_0 = gr.wavfile_source(
"/media/dimitris/mywork/gr/dimitris/rds/trunk/src/python/limmenso_stereo.wav",
True)
self.low_pass_filter_0 = gr.interp_fir_filter_fff(
1,
firdes.low_pass(1, usrp_rate, 1.5e3, 2e3, firdes.WIN_HAMMING,
6.76))
self.low_pass_filter_0_0 = gr.interp_fir_filter_fff(
1,
firdes.low_pass(1, usrp_rate, 15e3, 2e3, firdes.WIN_HAMMING, 6.76))
self.usrp_simple_sink_x_0 = grc_usrp.simple_sink_c(which=0, side="A")
self.usrp_simple_sink_x_0.set_interp_rate(500)
self.usrp_simple_sink_x_0.set_frequency(107.2e6, verbose=True)
self.usrp_simple_sink_x_0.set_gain(0)
self.usrp_simple_sink_x_0.set_enable(True)
self.usrp_simple_sink_x_0.set_auto_tr(True)
self.wxgui_fftsink2_0 = fftsink2.fft_sink_f(
self.GetWin(),
baseband_freq=0,
y_per_div=20,
y_divs=10,
ref_level=0,
ref_scale=2.0,
sample_rate=usrp_rate,
fft_size=1024,
fft_rate=30,
average=False,
avg_alpha=None,
title="FFT Plot",
peak_hold=False,
)
self.Add(self.wxgui_fftsink2_0.win)
##################################################
# Connections
##################################################
self.connect((self.gr_sig_source_x_0, 0),
(self.gr_rds_rate_enforcer_0, 1))
self.connect((self.gr_char_to_float_0, 0),
(self.gr_rds_rate_enforcer_0, 0))
self.connect((self.gr_map_bb_0, 0), (self.gr_char_to_float_0, 0))
self.connect((self.gr_frequency_modulator_fc_0, 0),
(self.usrp_simple_sink_x_0, 0))
self.connect((self.gr_add_xx_1, 0),
(self.gr_frequency_modulator_fc_0, 0))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_add_xx_1, 1))
self.connect((self.gr_sub_xx_0, 0), (self.gr_multiply_xx_1, 2))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_multiply_xx_1, 1))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_multiply_xx_1, 0))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_multiply_xx_0, 3))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_multiply_xx_0, 2))
self.connect((self.blks2_rational_resampler_xxx_1_0, 0),
(self.gr_add_xx_0, 1))
self.connect((self.blks2_rational_resampler_xxx_1, 0),
(self.gr_add_xx_0, 0))
self.connect((self.blks2_rational_resampler_xxx_1_0, 0),
(self.gr_sub_xx_0, 1))
self.connect((self.blks2_rational_resampler_xxx_1, 0),
(self.gr_sub_xx_0, 0))
self.connect((self.gr_wavfile_source_0, 1),
(self.blks2_rational_resampler_xxx_1_0, 0))
self.connect((self.gr_wavfile_source_0, 0),
(self.blks2_rational_resampler_xxx_1, 0))
self.connect((self.gr_rds_data_encoder_0, 0),
(self.gr_diff_encoder_bb_0, 0))
self.connect((self.gr_diff_encoder_bb_0, 0), (self.gr_map_bb_1, 0))
self.connect((self.gr_map_bb_1, 0), (self.gr_unpack_k_bits_bb_0, 0))
self.connect((self.gr_unpack_k_bits_bb_0, 0), (self.gr_map_bb_0, 0))
self.connect((self.gr_rds_rate_enforcer_0, 0),
(self.low_pass_filter_0, 0))
self.connect((self.low_pass_filter_0, 0), (self.gr_multiply_xx_0, 0))
self.connect((self.gr_multiply_xx_0, 0), (self.band_pass_filter_0, 0))
self.connect((self.band_pass_filter_0, 0), (self.gr_add_xx_1, 0))
self.connect((self.gr_multiply_xx_1, 0), (self.band_pass_filter_1, 0))
self.connect((self.band_pass_filter_1, 0), (self.gr_add_xx_1, 3))
self.connect((self.gr_add_xx_1, 0), (self.wxgui_fftsink2_0, 0))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_multiply_xx_0, 1))
self.connect((self.gr_add_xx_0, 0), (self.low_pass_filter_0_0, 0))
self.connect((self.low_pass_filter_0_0, 0), (self.gr_add_xx_1, 2))
def __init__(self, frame, panel, vbox, argv):
stdgui2.std_top_block.__init__(self, frame, panel, vbox, argv)
parser = OptionParser(option_class=eng_option)
parser.add_option("-T", "--tx-subdev-spec", type="subdev", default=None, help="select USRP Tx side A or B")
parser.add_option(
"-f",
"--freq",
type="eng_float",
default=107.2e6,
help="set Tx frequency to FREQ [required]",
metavar="FREQ",
)
parser.add_option("--wavfile", type="string", default=None, help="open .wav audio file FILE")
parser.add_option("--xml", type="string", default="rds_data.xml", help="open .xml RDS data FILE")
(options, args) = parser.parse_args()
if len(args) != 0:
parser.print_help()
sys.exit(1)
usrp_interp = 500
self.u = usrp.sink_c(0, usrp_interp)
print "USRP Serial: ", self.u.serial_number()
usrp_rate = self.u.dac_rate() / usrp_interp # 256 kS/s
# determine the daughterboard subdevice we're using
if options.tx_subdev_spec is None:
options.tx_subdev_spec = usrp.pick_tx_subdevice(self.u)
self.u.set_mux(usrp.determine_tx_mux_value(self.u, options.tx_subdev_spec))
self.subdev = usrp.selected_subdev(self.u, options.tx_subdev_spec)
print "Using d'board", self.subdev.side_and_name()
# set max Tx gain, tune frequency and enable transmitter
gain = self.subdev.gain_range()[1]
self.subdev.set_gain(gain)
print "Gain set to", gain
if self.u.tune(self.subdev.which(), self.subdev, options.freq):
print "Tuned to", options.freq / 1e6, "MHz"
else:
sys.exit(1)
self.subdev.set_enable(True)
# open wav file containing floats in the [-1, 1] range, repeat
if options.wavfile is None:
print "Please provide a wavfile to transmit! Exiting\n"
sys.exit(1)
self.src = gr.wavfile_source(options.wavfile, True)
nchans = self.src.channels()
sample_rate = self.src.sample_rate()
bits_per_sample = self.src.bits_per_sample()
print nchans, "channels,", sample_rate, "samples/sec,", bits_per_sample, "bits/sample"
# resample to usrp rate
self.resample_left = blks2.rational_resampler_fff(usrp_rate, sample_rate)
self.resample_right = blks2.rational_resampler_fff(usrp_rate, sample_rate)
self.connect((self.src, 0), self.resample_left)
self.connect((self.src, 1), self.resample_right)
# create L+R (mono) and L-R (stereo)
self.audio_lpr = gr.add_ff()
self.audio_lmr = gr.sub_ff()
self.connect(self.resample_left, (self.audio_lpr, 0))
self.connect(self.resample_left, (self.audio_lmr, 0))
self.connect(self.resample_right, (self.audio_lpr, 1))
self.connect(self.resample_right, (self.audio_lmr, 1))
# low-pass filter for L+R
audio_lpr_taps = gr.firdes.low_pass(
0.5, # gain
usrp_rate, # sampling rate
15e3, # passband cutoff
1e3, # transition width
gr.firdes.WIN_HAMMING,
)
self.audio_lpr_filter = gr.fir_filter_fff(1, audio_lpr_taps)
self.connect(self.audio_lpr, self.audio_lpr_filter)
# create pilot tone at 19 kHz
self.pilot = gr.sig_source_f(
usrp_rate, gr.GR_SIN_WAVE, 19e3, 5e-2 # sampling rate # waveform # frequency
) # amplitude
# upconvert L-R to 38 kHz and band-pass
self.mix_stereo = gr.multiply_ff()
audio_lmr_taps = gr.firdes.band_pass(
80, # gain
usrp_rate, # sampling rate
38e3 - 15e3, # low cutoff
38e3 + 15e3, # high cutoff
1e3, # transition width
gr.firdes.WIN_HAMMING,
)
self.audio_lmr_filter = gr.fir_filter_fff(1, audio_lmr_taps)
self.connect(self.audio_lmr, (self.mix_stereo, 0))
self.connect(self.pilot, (self.mix_stereo, 1))
self.connect(self.pilot, (self.mix_stereo, 2))
self.connect(self.mix_stereo, self.audio_lmr_filter)
# create RDS bitstream
# diff-encode, manchester-emcode, NRZ
# enforce the 1187.5bps rate
# pulse shaping filter (matched with receiver)
# mix with 57kHz carrier (equivalent to BPSK)
self.rds_enc = rds.data_encoder("rds_data.xml")
self.diff_enc = gr.diff_encoder_bb(2)
self.manchester1 = gr.map_bb([1, 2])
self.manchester2 = gr.unpack_k_bits_bb(2)
self.nrz = gr.map_bb([-1, 1])
self.c2f = gr.char_to_float()
self.rate_enforcer = rds.rate_enforcer(usrp_rate)
pulse_shaping_taps = gr.firdes.low_pass(
1, # gain
usrp_rate, # sampling rate
1.5e3, # passband cutoff
2e3, # transition width
gr.firdes.WIN_HAMMING,
)
self.pulse_shaping = gr.fir_filter_fff(1, pulse_shaping_taps)
self.bpsk_mod = gr.multiply_ff()
self.connect(self.rds_enc, self.diff_enc, self.manchester1, self.manchester2, self.nrz, self.c2f)
self.connect(self.c2f, (self.rate_enforcer, 0))
self.connect(self.pilot, (self.rate_enforcer, 1))
self.connect(self.rate_enforcer, (self.bpsk_mod, 0))
self.connect(self.pilot, (self.bpsk_mod, 1))
self.connect(self.pilot, (self.bpsk_mod, 2))
self.connect(self.pilot, (self.bpsk_mod, 3))
# RDS band-pass filter
rds_filter_taps = gr.firdes.band_pass(
50, # gain
usrp_rate, # sampling rate
57e3 - 3e3, # low cutoff
57e3 + 3e3, # high cutoff
1e3, # transition width
gr.firdes.WIN_HAMMING,
)
self.rds_filter = gr.fir_filter_fff(1, rds_filter_taps)
self.connect(self.bpsk_mod, self.rds_filter)
# mix L+R, pilot, L-R and RDS
self.mixer = gr.add_ff()
self.connect(self.audio_lpr_filter, (self.mixer, 0))
self.connect(self.pilot, (self.mixer, 1))
self.connect(self.audio_lmr_filter, (self.mixer, 2))
self.connect(self.rds_filter, (self.mixer, 3))
# fm modulation, gain & TX
max_dev = 75e3
k = 2 * math.pi * max_dev / usrp_rate # modulator sensitivity
self.modulator = gr.frequency_modulator_fc(k)
self.gain = gr.multiply_const_cc(5e3)
self.connect(self.mixer, self.modulator, self.gain, self.u)
# plot an FFT to verify we are sending what we want
if 1:
self.fft = fftsink2.fft_sink_f(
panel, title="Pre FM modulation", fft_size=512 * 4, sample_rate=usrp_rate, y_per_div=20, ref_level=-20
)
self.connect(self.mixer, self.fft)
vbox.Add(self.fft.win, 1, wx.EXPAND)
if 0:
self.scope = scopesink2.scope_sink_f(panel, title="RDS encoder output", sample_rate=usrp_rate)
self.connect(self.rds_enc, self.scope)
vbox.Add(self.scope.win, 1, wx.EXPAND)
def __init__(self, frame, panel, vbox, argv):
stdgui2.std_top_block.__init__(self, frame, panel, vbox, argv)
parser = OptionParser(option_class=eng_option)
parser.add_option("-T",
"--tx-subdev-spec",
type="subdev",
default=None,
help="select USRP Tx side A or B")
parser.add_option("-f",
"--freq",
type="eng_float",
default=107.2e6,
help="set Tx frequency to FREQ [required]",
metavar="FREQ")
parser.add_option("--wavfile",
type="string",
default=None,
help="open .wav audio file FILE")
parser.add_option("--xml",
type="string",
default="rds_data.xml",
help="open .xml RDS data FILE")
(options, args) = parser.parse_args()
if len(args) != 0:
parser.print_help()
sys.exit(1)
usrp_interp = 500
self.u = usrp.sink_c(0, usrp_interp)
print "USRP Serial: ", self.u.serial_number()
usrp_rate = self.u.dac_rate() / usrp_interp # 256 kS/s
# determine the daughterboard subdevice we're using
if options.tx_subdev_spec is None:
options.tx_subdev_spec = usrp.pick_tx_subdevice(self.u)
self.u.set_mux(
usrp.determine_tx_mux_value(self.u, options.tx_subdev_spec))
self.subdev = usrp.selected_subdev(self.u, options.tx_subdev_spec)
print "Using d'board", self.subdev.side_and_name()
# set max Tx gain, tune frequency and enable transmitter
gain = self.subdev.gain_range()[1]
self.subdev.set_gain(gain)
print "Gain set to", gain
if self.u.tune(self.subdev.which(), self.subdev, options.freq):
print "Tuned to", options.freq / 1e6, "MHz"
else:
sys.exit(1)
self.subdev.set_enable(True)
# open wav file containing floats in the [-1, 1] range, repeat
if options.wavfile is None:
print "Please provide a wavfile to transmit! Exiting\n"
sys.exit(1)
self.src = gr.wavfile_source(options.wavfile, True)
nchans = self.src.channels()
sample_rate = self.src.sample_rate()
bits_per_sample = self.src.bits_per_sample()
print nchans, "channels,", sample_rate, "samples/sec,", \
bits_per_sample, "bits/sample"
# resample to usrp rate
self.resample_left = blks2.rational_resampler_fff(
usrp_rate, sample_rate)
self.resample_right = blks2.rational_resampler_fff(
usrp_rate, sample_rate)
self.connect((self.src, 0), self.resample_left)
self.connect((self.src, 1), self.resample_right)
# create L+R (mono) and L-R (stereo)
self.audio_lpr = gr.add_ff()
self.audio_lmr = gr.sub_ff()
self.connect(self.resample_left, (self.audio_lpr, 0))
self.connect(self.resample_left, (self.audio_lmr, 0))
self.connect(self.resample_right, (self.audio_lpr, 1))
self.connect(self.resample_right, (self.audio_lmr, 1))
# low-pass filter for L+R
audio_lpr_taps = gr.firdes.low_pass(
0.5, # gain
usrp_rate, # sampling rate
15e3, # passband cutoff
1e3, # transition width
gr.firdes.WIN_HAMMING)
self.audio_lpr_filter = gr.fir_filter_fff(1, audio_lpr_taps)
self.connect(self.audio_lpr, self.audio_lpr_filter)
# create pilot tone at 19 kHz
self.pilot = gr.sig_source_f(
usrp_rate, # sampling rate
gr.GR_SIN_WAVE, # waveform
19e3, # frequency
5e-2) # amplitude
# upconvert L-R to 38 kHz and band-pass
self.mix_stereo = gr.multiply_ff()
audio_lmr_taps = gr.firdes.band_pass(
80, # gain
usrp_rate, # sampling rate
38e3 - 15e3, # low cutoff
38e3 + 15e3, # high cutoff
1e3, # transition width
gr.firdes.WIN_HAMMING)
self.audio_lmr_filter = gr.fir_filter_fff(1, audio_lmr_taps)
self.connect(self.audio_lmr, (self.mix_stereo, 0))
self.connect(self.pilot, (self.mix_stereo, 1))
self.connect(self.pilot, (self.mix_stereo, 2))
self.connect(self.mix_stereo, self.audio_lmr_filter)
# create RDS bitstream
# diff-encode, manchester-emcode, NRZ
# enforce the 1187.5bps rate
# pulse shaping filter (matched with receiver)
# mix with 57kHz carrier (equivalent to BPSK)
self.rds_enc = rds.data_encoder('rds_data.xml')
self.diff_enc = gr.diff_encoder_bb(2)
self.manchester1 = gr.map_bb([1, 2])
self.manchester2 = gr.unpack_k_bits_bb(2)
self.nrz = gr.map_bb([-1, 1])
self.c2f = gr.char_to_float()
self.rate_enforcer = rds.rate_enforcer(usrp_rate)
pulse_shaping_taps = gr.firdes.low_pass(
1, # gain
usrp_rate, # sampling rate
1.5e3, # passband cutoff
2e3, # transition width
gr.firdes.WIN_HAMMING)
self.pulse_shaping = gr.fir_filter_fff(1, pulse_shaping_taps)
self.bpsk_mod = gr.multiply_ff()
self.connect (self.rds_enc, self.diff_enc, self.manchester1, \
self.manchester2, self.nrz, self.c2f)
self.connect(self.c2f, (self.rate_enforcer, 0))
self.connect(self.pilot, (self.rate_enforcer, 1))
self.connect(self.rate_enforcer, (self.bpsk_mod, 0))
self.connect(self.pilot, (self.bpsk_mod, 1))
self.connect(self.pilot, (self.bpsk_mod, 2))
self.connect(self.pilot, (self.bpsk_mod, 3))
# RDS band-pass filter
rds_filter_taps = gr.firdes.band_pass(
50, # gain
usrp_rate, # sampling rate
57e3 - 3e3, # low cutoff
57e3 + 3e3, # high cutoff
1e3, # transition width
gr.firdes.WIN_HAMMING)
self.rds_filter = gr.fir_filter_fff(1, rds_filter_taps)
self.connect(self.bpsk_mod, self.rds_filter)
# mix L+R, pilot, L-R and RDS
self.mixer = gr.add_ff()
self.connect(self.audio_lpr_filter, (self.mixer, 0))
self.connect(self.pilot, (self.mixer, 1))
self.connect(self.audio_lmr_filter, (self.mixer, 2))
self.connect(self.rds_filter, (self.mixer, 3))
# fm modulation, gain & TX
max_dev = 75e3
k = 2 * math.pi * max_dev / usrp_rate # modulator sensitivity
self.modulator = gr.frequency_modulator_fc(k)
self.gain = gr.multiply_const_cc(5e3)
self.connect(self.mixer, self.modulator, self.gain, self.u)
# plot an FFT to verify we are sending what we want
if 1:
self.fft = fftsink2.fft_sink_f(panel,
title="Pre FM modulation",
fft_size=512 * 4,
sample_rate=usrp_rate,
y_per_div=20,
ref_level=-20)
self.connect(self.mixer, self.fft)
vbox.Add(self.fft.win, 1, wx.EXPAND)
if 0:
self.scope = scopesink2.scope_sink_f(panel,
title="RDS encoder output",
sample_rate=usrp_rate)
self.connect(self.rds_enc, self.scope)
vbox.Add(self.scope.win, 1, wx.EXPAND)