def __init__(self): gr.top_block.__init__(self) self._nsamples = 1000000 self._audio_rate = 8000 # Set up N channels with their own baseband and IF frequencies self._N = 5 chspacing = 16000 freq = [10, 20, 30, 40, 50] f_lo = [0, 1*chspacing, -1*chspacing, 2*chspacing, -2*chspacing] self._if_rate = 4*self._N*self._audio_rate # Create a signal source and frequency modulate it self.sum = gr.add_cc () for n in xrange(self._N): sig = gr.sig_source_f(self._audio_rate, gr.GR_SIN_WAVE, freq[n], 0.5) fm = fmtx(f_lo[n], self._audio_rate, self._if_rate) self.connect(sig, fm) self.connect(fm, (self.sum, n)) self.head = gr.head(gr.sizeof_gr_complex, self._nsamples) self.snk_tx = gr.vector_sink_c() self.channel = blks2.channel_model(0.1) self.connect(self.sum, self.head, self.channel, self.snk_tx) # Design the channlizer self._M = 10 bw = chspacing/2.0 t_bw = chspacing/10.0 self._chan_rate = self._if_rate / self._M self._taps = gr.firdes.low_pass_2(1, self._if_rate, bw, t_bw, attenuation_dB=100, window=gr.firdes.WIN_BLACKMAN_hARRIS) tpc = math.ceil(float(len(self._taps)) / float(self._M)) print "Number of taps: ", len(self._taps) print "Number of channels: ", self._M print "Taps per channel: ", tpc self.pfb = blks2.pfb_channelizer_ccf(self._M, self._taps) self.connect(self.channel, self.pfb) # Create a file sink for each of M output channels of the filter and connect it self.fmdet = list() self.squelch = list() self.snks = list() for i in xrange(self._M): self.fmdet.append(blks2.nbfm_rx(self._audio_rate, self._chan_rate)) self.squelch.append(blks2.standard_squelch(self._audio_rate*10)) self.snks.append(gr.vector_sink_f()) self.connect((self.pfb, i), self.fmdet[i], self.squelch[i], self.snks[i])
def __init__(self, subdev_spec, gain, audio_output): gr.hier_block2.__init__(self, "receive_path", gr.io_signature(0, 0, 0), # Input signature gr.io_signature(0, 0, 0)) # Output signature self.u = usrp.source_c () adc_rate = self.u.adc_rate() self.if_rate = 256e3 # 256 kS/s usrp_decim = int(adc_rate // self.if_rate) if_decim = 4 self.u.set_decim_rate(usrp_decim) self.quad_rate = self.if_rate // if_decim # 64 kS/s audio_decim = 2 audio_rate = self.quad_rate // audio_decim # 32 kS/s if subdev_spec is None: subdev_spec = usrp.pick_rx_subdevice(self.u) self.subdev = usrp.selected_subdev(self.u, subdev_spec) print "RX using", self.subdev.name() self.u.set_mux(usrp.determine_rx_mux_value(self.u, subdev_spec)) # Create filter to get actual channel we want chan_coeffs = gr.firdes.low_pass (1.0, # gain self.if_rate, # sampling rate 13e3, # low pass cutoff freq 4e3, # width of trans. band gr.firdes.WIN_HANN) # filter type print "len(rx_chan_coeffs) =", len(chan_coeffs) # Decimating Channel filter with frequency translation # complex in and out, float taps self.ddc = gr.freq_xlating_fir_filter_ccf(if_decim, # decimation rate chan_coeffs, # taps 0, # frequency translation amount self.if_rate) # input sample rate # instantiate the guts of the single channel receiver self.fmrx = blks2.nbfm_rx(audio_rate, self.quad_rate) # standard squelch block self.squelch = blks2.standard_squelch(audio_rate) # audio gain / mute block self._audio_gain = gr.multiply_const_ff(1.0) # sound card as final sink audio_sink = audio.sink (int(audio_rate), audio_output) # now wire it all together self.connect (self.u, self.ddc, self.fmrx, self.squelch, self._audio_gain, audio_sink) if gain is None: # if no gain was specified, use the mid-point in dB g = self.subdev.gain_range() gain = float(g[0]+g[1])/2 self.enabled = True self.set_gain(gain) v = self.volume_range() self.set_volume((v[0]+v[1])/2) s = self.squelch_range() self.set_squelch((s[0]+s[1])/2)
def __init__(self, args, gain, audio_output): gr.hier_block2.__init__(self, "receive_path", gr.io_signature(0, 0, 0), # Input signature gr.io_signature(0, 0, 0)) # Output signature self.u = uhd.usrp_source(device_addr=args, io_type=uhd.io_type.COMPLEX_FLOAT32, num_channels=1) self.if_rate = 256e3 self.quad_rate = 64e3 self.audio_rate = 32e3 self.u.set_samp_rate(self.if_rate) dev_rate = self.u.get_samp_rate() # Create filter to get actual channel we want nfilts = 32 chan_coeffs = gr.firdes.low_pass (nfilts, # gain nfilts*dev_rate, # sampling rate 13e3, # low pass cutoff freq 4e3, # width of trans. band gr.firdes.WIN_HANN) # filter type rrate = self.quad_rate / dev_rate self.resamp = blks2.pfb_arb_resampler_ccf(rrate, chan_coeffs, nfilts) # instantiate the guts of the single channel receiver self.fmrx = blks2.nbfm_rx(self.audio_rate, self.quad_rate) # standard squelch block self.squelch = blks2.standard_squelch(self.audio_rate) # audio gain / mute block self._audio_gain = gr.multiply_const_ff(1.0) # sound card as final sink audio_sink = audio.sink (int(self.audio_rate), audio_output) # now wire it all together self.connect (self.u, self.resamp, self.fmrx, self.squelch, self._audio_gain, audio_sink) if gain is None: # if no gain was specified, use the mid-point in dB g = self.u.get_gain_range() gain = float(g.start() + g.stop())/2.0 self.enabled = True self.set_gain(gain) v = self.volume_range() self.set_volume((v[0]+v[1])/2) s = self.squelch_range() self.set_squelch((s[0]+s[1])/2) # Set the subdevice spec if(spec): self.u.set_subdev_spec(spec, 0) # Set the antenna if(antenna): self.u.set_antenna(antenna, 0)
def __init__(self, subdev_spec, gain, audio_output): gr.hier_block2.__init__( self, "receive_path", gr.io_signature(0, 0, 0), # Input signature gr.io_signature(0, 0, 0)) # Output signature self.u = usrp.source_c() adc_rate = self.u.adc_rate() self.if_rate = 256e3 # 256 kS/s usrp_decim = int(adc_rate // self.if_rate) if_decim = 4 self.u.set_decim_rate(usrp_decim) self.quad_rate = self.if_rate // if_decim # 64 kS/s audio_decim = 2 self.audio_rate = self.quad_rate // audio_decim # 32 kS/s if subdev_spec is None: subdev_spec = usrp.pick_rx_subdevice(self.u) self.subdev = usrp.selected_subdev(self.u, subdev_spec) print "Using RX d'board %s" % (self.subdev.side_and_name(), ) self.u.set_mux(usrp.determine_rx_mux_value(self.u, subdev_spec)) # Create filter to get actual channel we want chan_coeffs = gr.firdes.low_pass( 1.0, # gain self.if_rate, # sampling rate 8e3, # low pass cutoff freq 2e3, # width of trans. band gr.firdes.WIN_HANN) # filter type print "len(rx_chan_coeffs) =", len(chan_coeffs) # Decimating Channel filter with frequency translation # complex in and out, float taps self.ddc = gr.freq_xlating_fir_filter_ccf( if_decim, # decimation rate chan_coeffs, # taps 0, # frequency translation amount self.if_rate) # input sample rate if USE_SIMPLE_SQUELCH: self.squelch = gr.simple_squelch_cc(20) else: self.squelch = blks2.standard_squelch(self.audio_rate) # instantiate the guts of the single channel receiver self.fmrx = blks2.nbfm_rx(self.audio_rate, self.quad_rate) # audio gain / mute block self._audio_gain = gr.multiply_const_ff(1.0) # sound card as final sink audio_sink = audio.sink(int(self.audio_rate), audio_output) # now wire it all together if USE_SIMPLE_SQUELCH: self.connect(self.u, self.ddc, self.squelch, self.fmrx, self._audio_gain, audio_sink) else: self.connect(self.u, self.ddc, self.fmrx, self.squelch, self._audio_gain, audio_sink) if gain is None: # if no gain was specified, use the mid-point in dB g = self.subdev.gain_range() gain = float(g[0] + g[1]) / 2 self.set_gain(gain) v = self.volume_range() self.set_volume((v[0] + v[1]) / 2) s = self.squelch_range() self.set_squelch((s[0] + s[1]) / 2)