Beispiel #1
0
    def __init__(self):
        gr.top_block.__init__(self)

        parser = ArgumentParser()
        parser.add_argument("-O", "--audio-output", default="",
                          help="pcm output device name.  E.g., hw:0,0 or /dev/dsp")
        parser.add_argument("-i", "--input-rate", type=eng_float, default=8000,
                          help="set input sample rate to RATE %(default)r")
        parser.add_argument("-o", "--output-rate", type=eng_float, default=48000,
                          help="set output sample rate to RATE %(default)r")
        args = parser.parse_args()
        input_rate = int(args.input_rate)
        output_rate = int(args.output_rate)

        interp = gru.lcm(input_rate / output_rate, input_rate)
        decim = gru.lcm(input_rate / output_rate, output_rate)

        print("interp =", interp)
        print("decim  =", decim)

        ampl = 0.1
        src0 = analog.sig_source_f(input_rate, analog.GR_SIN_WAVE, 650, ampl)
        rr = filter.rational_resampler_fff(interp, decim)
        dst = audio.sink(output_rate, args.audio_output)
        self.connect(src0, rr, (dst, 0))
    def __init__(self):
        gr.top_block.__init__(self)

        parser = OptionParser(option_class=eng_option)
        parser.add_option("-O", "--audio-output", type="string", default="",
                          help="pcm output device name.  E.g., hw:0,0 or /dev/dsp")
        parser.add_option("-i", "--input-rate", type="eng_float", default=8000,
                          help="set input sample rate to RATE (%default)")
        parser.add_option("-o", "--output-rate", type="eng_float", default=48000,
                          help="set output sample rate to RATE (%default)")
        (options, args) = parser.parse_args()
        if len(args) != 0:
            parser.print_help()
            raise SystemExit, 1

        input_rate = int(options.input_rate)
        output_rate = int(options.output_rate)

        interp = gru.lcm(input_rate, output_rate) / input_rate
        decim = gru.lcm(input_rate, output_rate) / output_rate

        print "interp =", interp
        print "decim  =", decim

        ampl = 0.1
        src0 = analog.sig_source_f(input_rate, analog.GR_SIN_WAVE, 650, ampl)
        rr = filter.rational_resampler_fff(interp, decim)
        dst = audio.sink(output_rate, options.audio_output)
        self.connect(src0, rr, (dst, 0))
Beispiel #3
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    def __init__(self):
        gr.top_block.__init__(self)

        parser = ArgumentParser()
        parser.add_argument(
            "-O",
            "--audio-output",
            default="",
            help="pcm output device name.  E.g., hw:0,0 or /dev/dsp")
        parser.add_argument("-i",
                            "--input-rate",
                            type=eng_float,
                            default=8000,
                            help="set input sample rate to RATE %(default)r")
        parser.add_argument("-o",
                            "--output-rate",
                            type=eng_float,
                            default=48000,
                            help="set output sample rate to RATE %(default)r")
        args = parser.parse_args()
        input_rate = int(args.input_rate)
        output_rate = int(args.output_rate)

        interp = gru.lcm(input_rate / output_rate, input_rate)
        decim = gru.lcm(input_rate / output_rate, output_rate)

        print("interp =", interp)
        print("decim  =", decim)

        ampl = 0.1
        src0 = analog.sig_source_f(input_rate, analog.GR_SIN_WAVE, 650, ampl)
        rr = filter.rational_resampler_fff(interp, decim)
        dst = audio.sink(output_rate, args.audio_output)
        self.connect(src0, rr, (dst, 0))
Beispiel #4
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    def __init__(self, channel_rate, threshold):
        gr.hier_block2.__init__(self, "ppm_demod",
                              gr.io_signature(1, 1, gr.sizeof_gr_complex),
                              gr.io_signature(1, 1, 512))

        chan_rate = 8000000 # Minimum sample rate

        if channel_rate < chan_rate:
            raise ValueError, "Invalid channel rate %d. Must be 8000000 sps or higher" % (channel_rate)
        
        if channel_rate >= 10000000:
            chan_rate = 10000000    # Higher Performance Receiver

        # if rate is not supported then resample
        if channel_rate != chan_rate:
            interp = gru.lcm(channel_rate, chan_rate)/channel_rate
            decim  = gru.lcm(channel_rate, chan_rate)/chan_rate
            self.RESAMP = rational_resampler_ccf(self, interp, decim)

        # Calculate the leading edge threshold per sample time
        leading_edge = risetime_threshold_db/(chan_rate/data_rate)

        # Calculate the number of following samples above threshold needed to make a sample a valid pulse position
        valid_pulse_position = 2
        if chan_rate == 10000000:
            valid_pulse_position = 3

        # Demodulate AM with classic sqrt (I*I + Q*Q)
        self.MAG = gr.complex_to_mag()
        self.DETECT = air.ms_pulse_detect(leading_edge, threshold, valid_pulse_position) # Attack, Threshold, Pulsewidth
        self.SYNC = air.ms_preamble(chan_rate)
        self.FRAME = air.ms_framer(chan_rate)
        self.BIT   = air.ms_ppm_decode(chan_rate)
        self.PARITY = air.ms_parity()
        self.EC    =  air.ms_ec_brute()

        if channel_rate != chan_rate:
            # Resample the stream first
            self.connect(self, self.RESAMP, self.MAG, self.DETECT)
        else: 
            self.connect(self, self.MAG, self.DETECT)

        self.connect((self.DETECT, 0), (self.SYNC, 0))
        self.connect((self.DETECT, 1), (self.SYNC, 1))
        self.connect((self.SYNC, 0), (self.FRAME, 0))
        self.connect((self.SYNC, 1), (self.FRAME, 1))
        self.connect((self.FRAME, 0), (self.BIT, 0))
        self.connect((self.FRAME, 1), (self.BIT, 1))
        self.connect(self.BIT, self.PARITY, self.EC, self)
Beispiel #5
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	def __init__(self):
		gr.top_block.__init__(self)
		input_sample_rate = 1e6
		symbol_rate = 152.34e3
		output_samples_per_symbol = 5
		output_sample_rate = output_samples_per_symbol * symbol_rate
		# least common multiple
		lcm = gru.lcm(input_sample_rate, output_sample_rate)
		intrp = int(lcm // input_sample_rate)
		decim = int(lcm // output_sample_rate)
		print intrp
		print decim
		resampler = blks2.rational_resampler_ccc(intrp, decim, None, None)
		src = gr.file_source(gr.sizeof_gr_complex, "infile")
		sink = gr.file_sink(gr.sizeof_float, "outfile")
		f2c = gr.float_to_complex()
		c2r = gr.complex_to_real()
		#ddc_coeffs = \
			#gr.firdes.low_pass (1.0,           # gain
				#input_sample_rate,   # sampling rate
				#2e3,         # low pass cutoff freq
				#6e3,         # width of trans. band
				#gr.firdes.WIN_HANN)
		# just grab the lower sideband:
		#ddc =  gr.freq_xlating_fir_filter_ccf(1,ddc_coeffs,-111.5e3,input_sample_rate)
		qdemod = gr.quadrature_demod_cf(1.0)
		lp_coeffs = \
			gr.firdes.low_pass (1.0,           # gain
				output_sample_rate,   # sampling rate
				symbol_rate,         # low pass cutoff freq
				symbol_rate,         # width of trans. band
				gr.firdes.WIN_HANN)
		lp = gr.fir_filter_fff (1,lp_coeffs)
		self.connect(src,resampler,qdemod,lp,sink)
Beispiel #6
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    def __init__(self, output_rate):

	gr.hier_block2.__init__(self, "p25_c4fm_mod_bf",
				gr.io_signature(1, 1, gr.sizeof_char),  # Input signature
				gr.io_signature(1, 1, gr.sizeof_float)) # Output signature

        symbol_rate = 4800   # P25 baseband symbol rate
        lcm = gru.lcm(symbol_rate, output_rate)
        self._interp_factor = int(lcm // symbol_rate)
        self._decimation = int(lcm // output_rate)
        self._excess_bw =0.2

        mod_map = [1.0/3.0, 1.0, -(1.0/3.0), -1.0]
        self.C2S = gr.chunks_to_symbols_bf(mod_map)

        ntaps = 11 * self._interp_factor
        rrc_taps = gr.firdes.root_raised_cosine(
            self._interp_factor, # gain (since we're interpolating by sps)
            lcm,                 # sampling rate
            symbol_rate,
            self._excess_bw,     # excess bandwidth (roll-off factor)
            ntaps)

        self.rrc_filter = gr.interp_fir_filter_fff(self._interp_factor, rrc_taps)
        
        # FM pre-emphasis filter
        shaping_coeffs = [-0.018, 0.0347, 0.0164, -0.0064, -0.0344, -0.0522, -0.0398, 0.0099, 0.0798, 0.1311, 0.121, 0.0322, -0.113, -0.2499, -0.3007, -0.2137, -0.0043, 0.2825, 0.514, 0.604, 0.514, 0.2825, -0.0043, -0.2137, -0.3007, -0.2499, -0.113, 0.0322, 0.121, 0.1311, 0.0798, 0.0099, -0.0398, -0.0522, -0.0344, -0.0064, 0.0164, 0.0347, -0.018]
        self.shaping_filter = gr.fir_filter_fff(1, shaping_coeffs)

        # generate output at appropriate rate
        self.decimator = blks2.rational_resampler_fff(1, self._decimation)

        self.connect(self, self.C2S, self.rrc_filter, self.shaping_filter, self.decimator, self)
Beispiel #7
0
 def __init__(self):
     gr.top_block.__init__(self)
     input_sample_rate = 1e6
     symbol_rate = 152.34e3
     output_samples_per_symbol = 5
     output_sample_rate = output_samples_per_symbol * symbol_rate
     # least common multiple
     lcm = gru.lcm(input_sample_rate, output_sample_rate)
     intrp = int(lcm // input_sample_rate)
     decim = int(lcm // output_sample_rate)
     print intrp
     print decim
     resampler = blks2.rational_resampler_ccc(intrp, decim, None, None)
     src = gr.file_source(gr.sizeof_gr_complex, "infile")
     sink = gr.file_sink(gr.sizeof_float, "outfile")
     f2c = gr.float_to_complex()
     c2r = gr.complex_to_real()
     #ddc_coeffs = \
     #gr.firdes.low_pass (1.0,           # gain
     #input_sample_rate,   # sampling rate
     #2e3,         # low pass cutoff freq
     #6e3,         # width of trans. band
     #gr.firdes.WIN_HANN)
     # just grab the lower sideband:
     #ddc =  gr.freq_xlating_fir_filter_ccf(1,ddc_coeffs,-111.5e3,input_sample_rate)
     qdemod = gr.quadrature_demod_cf(1.0)
     lp_coeffs = \
      gr.firdes.low_pass (1.0,           # gain
       output_sample_rate,   # sampling rate
       symbol_rate,         # low pass cutoff freq
       symbol_rate,         # width of trans. band
       gr.firdes.WIN_HANN)
     lp = gr.fir_filter_fff(1, lp_coeffs)
     self.connect(src, resampler, qdemod, lp, sink)
Beispiel #8
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    def __init__(self,
                 output_sample_rate=_def_output_sample_rate,
                 reverse=_def_reverse,
                 verbose=_def_verbose,
                 log=_def_log):
        """
	Hierarchical block for RRC-filtered P25 FM modulation.

	The input is a dibit (P25 symbol) stream (char, not packed) and the
	output is the float "C4FM" signal at baseband, suitable for application
        to an FM modulator stage

        Input is at the base symbol rate (4800), output sample rate is
        typically either 32000 (USRP TX chain) or 48000 (sound card)

	@param output_sample_rate: output sample rate
	@type output_sample_rate: integer
        @param reverse: reverse polarity flag
        @type reverse: bool
        @param verbose: Print information about modulator?
        @type verbose: bool
        @param debug: Print modulation data to files?
        @type debug: bool
	"""

	gr.hier_block2.__init__(self, "p25_c4fm_mod_bf",
				gr.io_signature(1, 1, gr.sizeof_char),       # Input signature
				gr.io_signature(1, 1, gr.sizeof_float)) # Output signature

        input_sample_rate = 4800   # P25 baseband symbol rate
        lcm = gru.lcm(input_sample_rate, output_sample_rate)
        self._interp_factor = int(lcm // input_sample_rate)
        self._decimation = int(lcm // output_sample_rate)

        mod_map = [1.0/3.0, 1.0, -(1.0/3.0), -1.0]
        self.C2S = digital.chunks_to_symbols_bf(mod_map)
        if reverse:
            self.polarity = blocks.multiply_const_ff(-1)
        else:
            self.polarity = blocks.multiply_const_ff( 1)

        self.filter = filter.interp_fir_filter_fff(self._interp_factor, c4fm_taps(sample_rate=output_sample_rate).generate())

        if verbose:
            self._print_verbage()
        
        if log:
            self._setup_logging()

        self.connect(self, self.C2S, self.polarity, self.filter)
        if (self._decimation > 1):
            self.decimator = filter.rational_resampler_fff(1, self._decimation)
            self.connect(self.filter, self.decimator, self)
        else:
            self.connect(self.filter, self)
Beispiel #9
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    def __init__(self):
        gr.top_block.__init__(self)

        parser = OptionParser(option_class=eng_option)
        parser.add_option(
            "-O",
            "--audio-output",
            type="string",
            default="",
            help="pcm output device name.  E.g., hw:0,0 or /dev/dsp")
        parser.add_option("-i",
                          "--input-rate",
                          type="eng_float",
                          default=8000,
                          help="set input sample rate to RATE (%default)")
        parser.add_option("-o",
                          "--output-rate",
                          type="eng_float",
                          default=48000,
                          help="set output sample rate to RATE (%default)")
        (options, args) = parser.parse_args()
        if len(args) != 0:
            parser.print_help()
            raise SystemExit, 1

        input_rate = int(options.input_rate)
        output_rate = int(options.output_rate)

        interp = gru.lcm(input_rate, output_rate) / input_rate
        decim = gru.lcm(input_rate, output_rate) / output_rate

        print "interp =", interp
        print "decim  =", decim

        ampl = 0.1
        src0 = analog.sig_source_f(input_rate, analog.GR_SIN_WAVE, 650, ampl)
        rr = filter.rational_resampler_fff(interp, decim)
        dst = audio.sink(output_rate, options.audio_output)
        self.connect(src0, rr, (dst, 0))
Beispiel #10
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    def __init__(self):
        gr.top_block.__init__(self)

        parser = OptionParser(option_class=eng_option)
        parser.add_option("-I", "--filename", type="string", help="read input from wav FILE")
        parser.add_option("-s", "--input-rate", type="eng_float", default="500k",
                          help="set sample rate to RATE (500k)")
        parser.add_option("-O", "--outname", type="string", help="output to wav file FILE")
        parser.add_option("-r", "--output-rate", type="eng_float", default="192k",
                          help="set output sample rate to RATE (192k)")
        parser.add_option("-F", "--filter", action="store_true", default=False,
                          help="filter out audible sounds, retain ultrasonic")
        (options, args) = parser.parse_args()
        if len(args) != 0:
            parser.print_help()
            raise SystemExit, 1


        src = gr.wavfile_source (options.filename)

        input_rate = int(options.input_rate)
        output_rate = int(options.output_rate) 
        interp = gru.lcm(input_rate, output_rate) / input_rate
        decim = gru.lcm(input_rate, output_rate) / output_rate

        dst = gr.wavfile_sink (options.outname, 1, output_rate)

        rr = blks2.rational_resampler_fff(int(interp), int(decim))

        if options.filter:
            highpass = gr.firdes.high_pass (1,                # gain
                                  output_rate,            # sampling rate
                                  15000,               # cutoff freq
                                  2000,                # width of trans. band
                                  gr.firdes.WIN_HANN) # filter type
            filt = gr.fir_filter_fff(1,highpass)
            self.connect (src, rr, filt, dst)
        else:
            self.connect (src, rr, dst)
Beispiel #11
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    def __init__(self):
	"""
        Con gr.top_block.__init__(self) se llama a la funcion inicial del modulo top_block del
        paquete gr y se pasa como argumento el objeto creado.

	A continuación, podemos agregar diferentes PARAMETROS que el usuario puede especificar en la línea de comando 

	La siguiente línea: (options, args) = parser.parse_args(), se utiliza para analizar la entrada del usuario y proporcionarla en un formato fácil de usar
        """
        gr.top_block.__init__(self)
        parser = OptionParser(option_class=eng_option)
        parser.add_option("-O", "--audio-output", type="string", default="",
                          help="pcm output device name.  E.g., hw:0,0 or /dev/dsp")
        parser.add_option("-i", "--input-rate", type="eng_float", default=8000,
                          help="set input sample rate to RATE (%default)")
        parser.add_option("-o", "--output-rate", type="eng_float", default=48000,
                          help="set output sample rate to RATE (%default)")
        (options, args) = parser.parse_args()

        if len(args) != 0:
	
 

            parser.print_help()
            raise SystemExit, 1
        input_rate = int(options.input_rate)
        output_rate = int(options.output_rate)

        interp = gru.lcm(input_rate, output_rate) / input_rate
        decim = gru.lcm(input_rate, output_rate) / output_rate

        print "interp =", interp
        print "decim  =", decim
        ampl = 0.1
        src0 = analog.sig_source_f(input_rate, analog.GR_SIN_WAVE, 650, ampl)
        rr = filter.rational_resampler_fff(interp, decim)
        dst = audio.sink(output_rate, options.audio_output)
	self.connect(src0, rr, (dst, 0))
Beispiel #12
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    def __init__(self):
        gr.top_block.__init__(self)
        parser = OptionParser(option_class=eng_option)

        parser.add_option("-c", "--calibration", type="int", default=0, help="freq offset")
        parser.add_option("-i", "--input-file", type="string", default="in.dat", help="specify the input file")
        parser.add_option("-l", "--log", action="store_true", default=False, help="dump debug .dat files")
        parser.add_option("-L", "--low-pass", type="eng_float", default=15e3, 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("-s", "--sample-rate", type="int", default=250000, help="input sample rate")
        parser.add_option("-v", "--verbose", action="store_true", default=False, help="dump demodulation data")
        (options, args) = parser.parse_args()
 
        sample_rate = options.sample_rate
        symbol_rate = 4800
        sps = 10
        # output rate will be 48,000
        ntaps = 11 * sps
        new_sample_rate = symbol_rate * sps
        lcm = gru.lcm(sample_rate, new_sample_rate)
        interp = lcm // sample_rate
        decim  = lcm // new_sample_rate

        channel_taps = gr.firdes.low_pass(1.0, sample_rate, options.low_pass, options.low_pass * 0.1, gr.firdes.WIN_HANN)

        FILTER = gr.freq_xlating_fir_filter_ccf(1, channel_taps, options.calibration, sample_rate)

        sys.stderr.write("interp: %d decim: %d\n" %(interp, decim))

        bpf_taps = gr.firdes.low_pass(1.0, sample_rate * interp, options.low_pass, options.low_pass * 0.1, gr.firdes.WIN_HANN)
        INTERPOLATOR = gr.interp_fir_filter_ccf (int(interp), bpf_taps)
        DECIMATOR = blks2.rational_resampler_ccf(1, int(decim))

        IN = gr.file_source(gr.sizeof_gr_complex, options.input_file)

        DEMOD = blks2.cqpsk_demod( samples_per_symbol = sps,
                                 excess_bw=0.35,
                                 costas_alpha=0.03,
                                 gain_mu=0.05,
                                 mu=0.05,
                                 omega_relative_limit=0.05,
                                 log=options.log,
                                 verbose=options.verbose)

        msgq = gr.msg_queue()
        DECODER = fsk4.apco25_f(msgq,0)

        self.connect(IN, FILTER, INTERPOLATOR, DECIMATOR, DEMOD, DECODER)
Beispiel #13
0
    def __init__(self, output_rate):

        gr.hier_block2.__init__(
            self,
            "p25_c4fm_mod_bf",
            gr.io_signature(1, 1, gr.sizeof_char),  # Input signature
            gr.io_signature(1, 1, gr.sizeof_float))  # Output signature

        symbol_rate = 4800  # P25 baseband symbol rate
        lcm = gru.lcm(symbol_rate, output_rate)
        self._interp_factor = int(lcm // symbol_rate)
        self._decimation = int(lcm // output_rate)
        self._excess_bw = 0.2

        mod_map = [1.0 / 3.0, 1.0, -(1.0 / 3.0), -1.0]
        self.C2S = gr.chunks_to_symbols_bf(mod_map)

        ntaps = 11 * self._interp_factor
        rrc_taps = gr.firdes.root_raised_cosine(
            self._interp_factor,  # gain (since we're interpolating by sps)
            lcm,  # sampling rate
            symbol_rate,
            self._excess_bw,  # excess bandwidth (roll-off factor)
            ntaps)

        self.rrc_filter = gr.interp_fir_filter_fff(self._interp_factor,
                                                   rrc_taps)

        # FM pre-emphasis filter
        shaping_coeffs = [
            -0.018, 0.0347, 0.0164, -0.0064, -0.0344, -0.0522, -0.0398, 0.0099,
            0.0798, 0.1311, 0.121, 0.0322, -0.113, -0.2499, -0.3007, -0.2137,
            -0.0043, 0.2825, 0.514, 0.604, 0.514, 0.2825, -0.0043, -0.2137,
            -0.3007, -0.2499, -0.113, 0.0322, 0.121, 0.1311, 0.0798, 0.0099,
            -0.0398, -0.0522, -0.0344, -0.0064, 0.0164, 0.0347, -0.018
        ]
        self.shaping_filter = gr.fir_filter_fff(1, shaping_coeffs)

        # generate output at appropriate rate
        self.decimator = blks2.rational_resampler_fff(1, self._decimation)

        self.connect(self, self.C2S, self.rrc_filter, self.shaping_filter,
                     self.decimator, self)
Beispiel #14
0
def _npadding_bytes(pkt_byte_len, spb):
    """
    Generate sufficient padding such that each packet ultimately ends
    up being a multiple of 512 bytes when sent across the USB.  We
    send 4-byte samples across the USB (16-bit I and 16-bit Q), thus
    we want to pad so that after modulation the resulting packet
    is a multiple of 128 samples.

    @param ptk_byte_len: len in bytes of packet, not including padding.
    @param spb: samples per baud == samples per bit (1 bit / baud with GMSK)
    @type spb: int

    @returns number of bytes of padding to append.
    """
    modulus = 128
    byte_modulus = gru.lcm(modulus / 8, spb) / spb
    r = pkt_byte_len % byte_modulus
    if r == 0:
        return 0
    return byte_modulus - r
def _npadding_bytes(pkt_byte_len, samples_per_symbol, bits_per_symbol):
    """
    Generate sufficient padding such that each packet ultimately ends
    up being a multiple of 512 bytes when sent across the USB.  We
    send 4-byte samples across the USB (16-bit I and 16-bit Q), thus
    we want to pad so that after modulation the resulting packet
    is a multiple of 128 samples.

    Args:
        ptk_byte_len: len in bytes of packet, not including padding.
        samples_per_symbol: samples per bit (1 bit / symbolwidth GMSK) (int)
        bits_per_symbol: bits per symbol (log2(modulation order)) (int)

    Returns:
        number of bytes of padding to append.
    """
    modulus = 128
    byte_modulus = gru.lcm(modulus/8, samples_per_symbol) * bits_per_symbol / samples_per_symbol
    r = pkt_byte_len % byte_modulus
    if r == 0:
        return 0
    return byte_modulus - r
Beispiel #16
0
    def __init__(self,
                 filter_gain=1.0,
                 sample_rate=_def_sample_rate,
                 symbol_rate=_def_symbol_rate,
                 span=_def_span,
                 verbose=_def_verbose,
                 log=_def_log):

        self.filter_gain = filter_gain
        self.sample_rate = sample_rate
        self.symbol_rate = symbol_rate
        self.span = span
        self.verbose = verbose
        self.log = log

        gr.hier_block2.__init__(
            self,
            "tx_nyquist_filter_ff",
            gr.io_signature(1, 1, gr.sizeof_float),  # Input signature
            gr.io_signature(1, 1, gr.sizeof_float))  # Output signature

        # Determine Interpolation factors.
        lcm = gru.lcm(self.symbol_rate, self.sample_rate)
        self.interpolation = int(lcm // self.symbol_rate)

        # Create Nyquist Raised Cosine filter.
        self.nyquist_filter = filter.interp_fir_filter_fff(
            self.interpolation,
            generate_taps(filter_gain=self.filter_gain * self.interpolation,
                          sample_rate=self.sample_rate,
                          symbol_rate=self.symbol_rate,
                          span=self.span,
                          generator=nyquist_filter_gen).generate())

        # Define blocks and connect them
        self.connect(self, self.nyquist_filter, self)
Beispiel #17
0
    def __init__(self,
                 filter_gain=1.0,
                 sample_rate=_def_sample_rate,
                 symbol_rate=_def_symbol_rate,
                 span=_def_span,
                 verbose=_def_verbose,
                 log=_def_log):

        self.filter_gain = filter_gain
        self.sample_rate = sample_rate
        self.symbol_rate = symbol_rate
        self.span = span
        self.verbose = verbose
        self.log = log

        gr.hier_block2.__init__(
            self,
            "tx_shaping_filter_ff",
            gr.io_signature(1, 1, gr.sizeof_float),  # Input signature
            gr.io_signature(1, 1, gr.sizeof_float))  # Output signature

        # Determine decimation factor.
        lcm = gru.lcm(self.symbol_rate, self.sample_rate)
        self.decimation = int(lcm // self.sample_rate)

        # Create the TX Shaping Filter.
        self.tx_shaping_filter = filter.fir_filter_fff(
            self.decimation,
            generate_taps(filter_gain=self.filter_gain,
                          sample_rate=self.sample_rate,
                          symbol_rate=self.symbol_rate,
                          span=self.span,
                          generator=tx_shaping_filter_gen).generate())

        # Define blocks and connect them
        self.connect(self, self.tx_shaping_filter, self)
Beispiel #18
0
    def __init__(self):
        gr.top_block.__init__(self)
        parser = OptionParser(option_class=eng_option)

        parser.add_option("-c",
                          "--calibration",
                          type="int",
                          default=0,
                          help="freq offset")
        parser.add_option("-i",
                          "--input-file",
                          type="string",
                          default="in.dat",
                          help="specify the input file")
        parser.add_option("-l",
                          "--log",
                          action="store_true",
                          default=False,
                          help="dump debug .dat files")
        parser.add_option("-L",
                          "--low-pass",
                          type="eng_float",
                          default=15e3,
                          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("-s",
                          "--sample-rate",
                          type="int",
                          default=250000,
                          help="input sample rate")
        parser.add_option("-v",
                          "--verbose",
                          action="store_true",
                          default=False,
                          help="dump demodulation data")
        (options, args) = parser.parse_args()

        sample_rate = options.sample_rate
        symbol_rate = 4800
        sps = 10
        # output rate will be 48,000
        ntaps = 11 * sps
        new_sample_rate = symbol_rate * sps
        lcm = gru.lcm(sample_rate, new_sample_rate)
        interp = lcm // sample_rate
        decim = lcm // new_sample_rate

        channel_taps = gr.firdes.low_pass(1.0, sample_rate, options.low_pass,
                                          options.low_pass * 0.1,
                                          gr.firdes.WIN_HANN)

        FILTER = gr.freq_xlating_fir_filter_ccf(1, channel_taps,
                                                options.calibration,
                                                sample_rate)

        sys.stderr.write("interp: %d decim: %d\n" % (interp, decim))

        bpf_taps = gr.firdes.low_pass(1.0, sample_rate * interp,
                                      options.low_pass, options.low_pass * 0.1,
                                      gr.firdes.WIN_HANN)
        INTERPOLATOR = gr.interp_fir_filter_ccf(int(interp), bpf_taps)
        DECIMATOR = blks2.rational_resampler_ccf(1, int(decim))

        IN = gr.file_source(gr.sizeof_gr_complex, options.input_file)

        DEMOD = blks2.cqpsk_demod(samples_per_symbol=sps,
                                  excess_bw=0.35,
                                  costas_alpha=0.03,
                                  gain_mu=0.05,
                                  mu=0.05,
                                  omega_relative_limit=0.05,
                                  log=options.log,
                                  verbose=options.verbose)

        msgq = gr.msg_queue()
        DECODER = fsk4.apco25_f(msgq, 0)

        self.connect(IN, FILTER, INTERPOLATOR, DECIMATOR, DEMOD, DECODER)
Beispiel #19
0
    def __init__(self,
                 output_sample_rate=_def_output_sample_rate,
                 excess_bw=_def_excess_bw,
                 reverse=_def_reverse,
                 verbose=_def_verbose,
                 log=_def_log):
        """
	Hierarchical block for RRC-filtered P25 FM modulation.

	The input is a dibit (P25 symbol) stream (char, not packed) and the
	output is the float "C4FM" signal at baseband, suitable for application
        to an FM modulator stage

        Input is at the base symbol rate (4800), output sample rate is
        typically either 32000 (USRP TX chain) or 48000 (sound card)

	@param output_sample_rate: output sample rate
	@type output_sample_rate: integer
	@param excess_bw: Root-raised cosine filter excess bandwidth
	@type excess_bw: float
        @param reverse: reverse polarity flag
        @type reverse: bool
        @param verbose: Print information about modulator?
        @type verbose: bool
        @param debug: Print modulation data to files?
        @type debug: bool
	"""

        gr.hier_block2.__init__(
            self,
            "p25_c4fm_mod_bf",
            gr.io_signature(1, 1, gr.sizeof_char),  # Input signature
            gr.io_signature(1, 1, gr.sizeof_float))  # Output signature

        input_sample_rate = 4800  # P25 baseband symbol rate
        lcm = gru.lcm(input_sample_rate, output_sample_rate)
        self._interp_factor = int(lcm // input_sample_rate)
        self._decimation = int(lcm // output_sample_rate)
        self._excess_bw = excess_bw

        mod_map = [1.0 / 3.0, 1.0, -(1.0 / 3.0), -1.0]
        self.C2S = gr.chunks_to_symbols_bf(mod_map)
        if reverse:
            self.polarity = gr.multiply_const_ff(-1)
        else:
            self.polarity = gr.multiply_const_ff(1)

        ntaps = 11 * self._interp_factor
        rrc_taps = gr.firdes.root_raised_cosine(
            self._interp_factor,  # gain (since we're interpolating by sps)
            lcm,  # sampling rate
            input_sample_rate,  # symbol rate
            self._excess_bw,  # excess bandwidth (roll-off factor)
            ntaps)

        # rrc_coeffs work slightly differently: each input sample
        # (from mod_map above) at 4800 rate, then 9 zeros are inserted
        # to bring to 48000 rate, then this filter is applied:
        # rrc_filter = gr.fir_filter_fff(1, rrc_coeffs)
        # FIXME: how to insert the 9 zero samples using gr ?
        # rrc_coeffs = [0, -0.003, -0.006, -0.009, -0.012, -0.014, -0.014, -0.013, -0.01, -0.006, 0, 0.007, 0.014, 0.02, 0.026, 0.029, 0.029, 0.027, 0.021, 0.012, 0, -0.013, -0.027, -0.039, -0.049, -0.054, -0.055, -0.049, -0.038, -0.021, 0, 0.024, 0.048, 0.071, 0.088, 0.098, 0.099, 0.09, 0.07, 0.039, 0, -0.045, -0.091, -0.134, -0.17, -0.193, -0.199, -0.184, -0.147, -0.085, 0, 0.105, 0.227, 0.36, 0.496, 0.629, 0.751, 0.854, 0.933, 0.983, 1, 0.983, 0.933, 0.854, 0.751, 0.629, 0.496, 0.36, 0.227, 0.105, 0, -0.085, -0.147, -0.184, -0.199, -0.193, -0.17, -0.134, -0.091, -0.045, 0, 0.039, 0.07, 0.09, 0.099, 0.098, 0.088, 0.071, 0.048, 0.024, 0, -0.021, -0.038, -0.049, -0.055, -0.054, -0.049, -0.039, -0.027, -0.013, 0, 0.012, 0.021, 0.027, 0.029, 0.029, 0.026, 0.02, 0.014, 0.007, 0, -0.006, -0.01, -0.013, -0.014, -0.014, -0.012, -0.009, -0.006, -0.003, 0]

        self.rrc_filter = gr.interp_fir_filter_fff(self._interp_factor,
                                                   rrc_taps)

        # FM pre-emphasis filter
        shaping_coeffs = [
            -0.018, 0.0347, 0.0164, -0.0064, -0.0344, -0.0522, -0.0398, 0.0099,
            0.0798, 0.1311, 0.121, 0.0322, -0.113, -0.2499, -0.3007, -0.2137,
            -0.0043, 0.2825, 0.514, 0.604, 0.514, 0.2825, -0.0043, -0.2137,
            -0.3007, -0.2499, -0.113, 0.0322, 0.121, 0.1311, 0.0798, 0.0099,
            -0.0398, -0.0522, -0.0344, -0.0064, 0.0164, 0.0347, -0.018
        ]
        self.shaping_filter = gr.fir_filter_fff(1, shaping_coeffs)

        if verbose:
            self._print_verbage()

        if log:
            self._setup_logging()

        self.connect(self, self.C2S, self.polarity, self.rrc_filter,
                     self.shaping_filter)
        if (self._decimation > 1):
            self.decimator = blks2.rational_resampler_fff(1, self._decimation)
            self.connect(self.shaping_filter, self.decimator, self)
        else:
            self.connect(self.shaping_filter, self)
Beispiel #20
0
    def __init__(self, frame, panel, vbox, argv):
        stdgui2.std_top_block.__init__(self, frame, panel, vbox, argv)

        self.frame = frame
        self.panel = panel

        parser = OptionParser(option_class=eng_option)
        parser.add_option("-R",
                          "--rx-subdev-spec",
                          type="subdev",
                          default=(0, 0),
                          help="select USRP Rx side A or B (default=A)")
        parser.add_option(
            "-d",
            "--decim",
            type="int",
            default=16,
            help="set fgpa decimation rate to DECIM [default=%default]")
        parser.add_option("-f",
                          "--freq",
                          type="eng_float",
                          default=None,
                          help="set frequency to FREQ",
                          metavar="FREQ")
        parser.add_option("-Q",
                          "--observing",
                          type="eng_float",
                          default=0.0,
                          help="set observing frequency to FREQ")
        parser.add_option("-a",
                          "--avg",
                          type="eng_float",
                          default=1.0,
                          help="set spectral averaging alpha")
        parser.add_option("-V",
                          "--favg",
                          type="eng_float",
                          default=2.0,
                          help="set folder averaging alpha")
        parser.add_option("-g",
                          "--gain",
                          type="eng_float",
                          default=None,
                          help="set gain in dB (default is midpoint)")
        parser.add_option("-l",
                          "--reflevel",
                          type="eng_float",
                          default=30.0,
                          help="Set pulse display reference level")
        parser.add_option("-L",
                          "--lowest",
                          type="eng_float",
                          default=1.5,
                          help="Lowest valid frequency bin")
        parser.add_option("-e",
                          "--longitude",
                          type="eng_float",
                          default=-76.02,
                          help="Set Observer Longitude")
        parser.add_option("-c",
                          "--latitude",
                          type="eng_float",
                          default=44.85,
                          help="Set Observer Latitude")
        parser.add_option("-F",
                          "--fft_size",
                          type="eng_float",
                          default=1024,
                          help="Size of FFT")

        parser.add_option("-t",
                          "--threshold",
                          type="eng_float",
                          default=2.5,
                          help="pulsar threshold")
        parser.add_option("-p",
                          "--lowpass",
                          type="eng_float",
                          default=100,
                          help="Pulse spectra cutoff freq")
        parser.add_option("-P", "--prefix", default="./", help="File prefix")
        parser.add_option("-u",
                          "--pulsefreq",
                          type="eng_float",
                          default=0.748,
                          help="Observation pulse rate")
        parser.add_option("-D",
                          "--dm",
                          type="eng_float",
                          default=1.0e-5,
                          help="Dispersion Measure")
        parser.add_option("-O",
                          "--doppler",
                          type="eng_float",
                          default=1.0,
                          help="Doppler ratio")
        parser.add_option("-B",
                          "--divbase",
                          type="eng_float",
                          default=20,
                          help="Y/Div menu base")
        parser.add_option("-I",
                          "--division",
                          type="eng_float",
                          default=100,
                          help="Y/Div")
        parser.add_option("-A",
                          "--audio_source",
                          default="plughw:0,0",
                          help="Audio input device spec")
        parser.add_option("-N",
                          "--num_pulses",
                          default=1,
                          type="eng_float",
                          help="Number of display pulses")
        (options, args) = parser.parse_args()
        if len(args) != 0:
            parser.print_help()
            sys.exit(1)

        self.show_debug_info = True

        self.reflevel = options.reflevel
        self.divbase = options.divbase
        self.division = options.division
        self.audiodev = options.audio_source
        self.mult = int(options.num_pulses)

        # Low-pass cutoff for post-detector filter
        # Set to 100Hz usually, since lots of pulsars fit in this
        #   range
        self.lowpass = options.lowpass

        # What is lowest valid frequency bin in post-detector FFT?
        # There's some pollution very close to DC
        self.lowest_freq = options.lowest

        # What (dB) threshold to use in determining spectral candidates
        self.threshold = options.threshold

        # Filename prefix for recording file
        self.prefix = options.prefix

        # Dispersion Measure (DM)
        self.dm = options.dm

        # Doppler shift, as a ratio
        #  1.0 == no doppler shift
        #  1.005 == a little negative shift
        #  0.995 == a little positive shift
        self.doppler = options.doppler

        #
        # Input frequency and observing frequency--not necessarily the
        #   same thing, if we're looking at the IF of some downconverter
        #   that's ahead of the USRP and daughtercard.  This distinction
        #   is important in computing the correct de-dispersion filter.
        #
        self.frequency = options.freq
        if options.observing <= 0:
            self.observing_freq = options.freq
        else:
            self.observing_freq = options.observing

        # build the graph
        self.u = usrp.source_c(decim_rate=options.decim)
        self.u.set_mux(
            usrp.determine_rx_mux_value(self.u, options.rx_subdev_spec))

        #
        # Recording file, in case we ever need to record baseband data
        #
        self.recording = gr.file_sink(gr.sizeof_char, "/dev/null")
        self.recording_state = False

        self.pulse_recording = gr.file_sink(gr.sizeof_short, "/dev/null")
        self.pulse_recording_state = False

        #
        # We come up with recording turned off, but the user may
        #  request recording later on
        self.recording.close()
        self.pulse_recording.close()

        #
        # Need these two for converting 12-bit baseband signals to 8-bit
        #
        self.tofloat = gr.complex_to_float()
        self.tochar = gr.float_to_char()

        # Need this for recording pulses (post-detector)
        self.toshort = gr.float_to_short()

        #
        # The spectral measurer sets this when it has a valid
        #   average spectral peak-to-peak distance
        # We can then use this to program the parameters for the epoch folder
        #
        # We set a sentimental value here
        self.pulse_freq = options.pulsefreq

        # Folder runs at this raw sample rate
        self.folder_input_rate = 20000

        # Each pulse in the epoch folder is sampled at 128 times the nominal
        #  pulse rate
        self.folding = 128

        #
        # Try to find candidate parameters for rational resampler
        #
        save_i = 0
        candidates = []
        for i in range(20, 300):
            input_rate = self.folder_input_rate
            output_rate = int(self.pulse_freq * i)
            interp = gru.lcm(input_rate, output_rate) / input_rate
            decim = gru.lcm(input_rate, output_rate) / output_rate
            if (interp < 500 and decim < 250000):
                candidates.append(i)

        # We didn't find anything, bail!
        if (len(candidates) < 1):
            print "Couldn't converge on resampler parameters"
            sys.exit(1)

        #
        # Now try to find candidate with the least sampling error
        #
        mindiff = 999.999
        for i in candidates:
            diff = self.pulse_freq * i
            diff = diff - int(diff)
            if (diff < mindiff):
                mindiff = diff
                save_i = i

        # Recompute rates
        input_rate = self.folder_input_rate
        output_rate = int(self.pulse_freq * save_i)

        # Compute new interp and decim, based on best candidate
        interp = gru.lcm(input_rate, output_rate) / input_rate
        decim = gru.lcm(input_rate, output_rate) / output_rate

        # Save optimized folding parameters, used later
        self.folding = save_i
        self.interp = int(interp)
        self.decim = int(decim)

        # So that we can view N pulses in the pulse viewer window
        FOLD_MULT = self.mult

        # determine the daughterboard subdevice we're using
        self.subdev = usrp.selected_subdev(self.u, options.rx_subdev_spec)
        self.cardtype = self.u.daughterboard_id(0)

        # Compute raw input rate
        input_rate = self.u.adc_freq() / self.u.decim_rate()

        # BW==input_rate for complex data
        self.bw = input_rate

        #
        # Set baseband filter bandwidth if DBS_RX:
        #
        if self.cardtype == usrp_dbid.DBS_RX:
            lbw = input_rate / 2
            if lbw < 1.0e6:
                lbw = 1.0e6
            self.subdev.set_bw(lbw)

        #
        # We use this as a crude volume control for the audio output
        #
        #self.volume = gr.multiply_const_ff(10**(-1))

        #
        # Create location data for ephem package
        #
        self.locality = ephem.Observer()
        self.locality.long = str(options.longitude)
        self.locality.lat = str(options.latitude)

        #
        # What is the post-detector LPF cutoff for the FFT?
        #
        PULSAR_MAX_FREQ = int(options.lowpass)

        # First low-pass filters down to input_rate/FIRST_FACTOR
        #   and decimates appropriately
        FIRST_FACTOR = int(input_rate / (self.folder_input_rate / 2))
        first_filter = gr.firdes.low_pass(1.0, input_rate,
                                          input_rate / FIRST_FACTOR,
                                          input_rate / (FIRST_FACTOR * 20),
                                          gr.firdes.WIN_HAMMING)

        # Second filter runs at the output rate of the first filter,
        #  And low-pass filters down to PULSAR_MAX_FREQ*10
        #
        second_input_rate = int(input_rate / (FIRST_FACTOR / 2))
        second_filter = gr.firdes.band_pass(1.0, second_input_rate, 0.10,
                                            PULSAR_MAX_FREQ * 10,
                                            PULSAR_MAX_FREQ * 1.5,
                                            gr.firdes.WIN_HAMMING)

        # Third filter runs at PULSAR_MAX_FREQ*20
        #   and filters down to PULSAR_MAX_FREQ
        #
        third_input_rate = PULSAR_MAX_FREQ * 20
        third_filter = gr.firdes_band_pass(1.0, third_input_rate, 0.10,
                                           PULSAR_MAX_FREQ,
                                           PULSAR_MAX_FREQ / 10.0,
                                           gr.firdes.WIN_HAMMING)

        #
        # Create the appropriate FFT scope
        #
        self.scope = ra_fftsink.ra_fft_sink_f(panel,
                                              fft_size=int(options.fft_size),
                                              sample_rate=PULSAR_MAX_FREQ * 2,
                                              title="Post-detector spectrum",
                                              ofunc=self.pulsarfunc,
                                              xydfunc=self.xydfunc,
                                              fft_rate=200)

        #
        # Tell scope we're looking from DC to PULSAR_MAX_FREQ
        #
        self.scope.set_baseband_freq(0.0)

        #
        # Setup stripchart for showing pulse profiles
        #
        hz = "%5.3fHz " % self.pulse_freq
        per = "(%5.3f sec)" % (1.0 / self.pulse_freq)
        sr = "%d sps" % (int(self.pulse_freq * self.folding))
        times = " %d Pulse Intervals" % self.mult
        self.chart = ra_stripchartsink.stripchart_sink_f(
            panel,
            sample_rate=1,
            stripsize=self.folding * FOLD_MULT,
            parallel=True,
            title="Pulse Profiles: " + hz + per + times,
            xlabel="Seconds @ " + sr,
            ylabel="Level",
            autoscale=True,
            divbase=self.divbase,
            scaling=1.0 / (self.folding * self.pulse_freq))
        self.chart.set_ref_level(self.reflevel)
        self.chart.set_y_per_div(self.division)

        # De-dispersion filter setup
        #
        # Do this here, just before creating the filter
        #  that will use the taps.
        #
        ntaps = self.compute_disp_ntaps(self.dm, self.bw, self.observing_freq)

        # Taps for the de-dispersion filter
        self.disp_taps = Numeric.zeros(ntaps, Numeric.Complex64)

        # Compute the de-dispersion filter now
        self.compute_dispfilter(self.dm, self.doppler, self.bw,
                                self.observing_freq)

        #
        # Call constructors for receive chains
        #

        #
        # Now create the FFT filter using the computed taps
        self.dispfilt = gr.fft_filter_ccc(1, self.disp_taps)

        #
        # Audio sink
        #
        #print "input_rate ", second_input_rate, "audiodev ", self.audiodev
        #self.audio = audio.sink(second_input_rate, self.audiodev)

        #
        # The three post-detector filters
        # Done this way to allow an audio path (up to 10Khz)
        # ...and also because going from xMhz down to ~100Hz
        # In a single filter doesn't seem to work.
        #
        self.first = gr.fir_filter_fff(FIRST_FACTOR / 2, first_filter)

        p = second_input_rate / (PULSAR_MAX_FREQ * 20)
        self.second = gr.fir_filter_fff(int(p), second_filter)
        self.third = gr.fir_filter_fff(10, third_filter)

        # Detector
        self.detector = gr.complex_to_mag_squared()

        self.enable_comb_filter = False
        # Epoch folder comb filter
        if self.enable_comb_filter == True:
            bogtaps = Numeric.zeros(512, Numeric.Float64)
            self.folder_comb = gr.fft_filter_ccc(1, bogtaps)

        # Rational resampler
        self.folder_rr = blks2.rational_resampler_fff(self.interp, self.decim)

        # Epoch folder bandpass
        bogtaps = Numeric.zeros(1, Numeric.Float64)
        self.folder_bandpass = gr.fir_filter_fff(1, bogtaps)

        # Epoch folder F2C/C2F
        self.folder_f2c = gr.float_to_complex()
        self.folder_c2f = gr.complex_to_float()

        # Epoch folder S2P
        self.folder_s2p = gr.serial_to_parallel(gr.sizeof_float,
                                                self.folding * FOLD_MULT)

        # Epoch folder IIR Filter (produces average pulse profiles)
        self.folder_iir = gr.single_pole_iir_filter_ff(
            1.0 / options.favg, self.folding * FOLD_MULT)

        #
        # Set all the epoch-folder goop up
        #
        self.set_folding_params()

        #
        # Start connecting configured modules in the receive chain
        #

        # Connect raw USRP to de-dispersion filter, detector
        self.connect(self.u, self.dispfilt, self.detector)

        # Connect detector output to FIR LPF
        #  in two stages, followed by the FFT scope
        self.connect(self.detector, self.first, self.second, self.third,
                     self.scope)

        # Connect audio output
        #self.connect(self.first, self.volume)
        #self.connect(self.volume, (self.audio, 0))
        #self.connect(self.volume, (self.audio, 1))

        # Connect epoch folder
        if self.enable_comb_filter == True:
            self.connect(self.first, self.folder_bandpass, self.folder_rr,
                         self.folder_f2c, self.folder_comb, self.folder_c2f,
                         self.folder_s2p, self.folder_iir, self.chart)

        else:
            self.connect(self.first, self.folder_bandpass, self.folder_rr,
                         self.folder_s2p, self.folder_iir, self.chart)

        # Connect baseband recording file (initially /dev/null)
        self.connect(self.u, self.tofloat, self.tochar, self.recording)

        # Connect pulse recording file (initially /dev/null)
        self.connect(self.first, self.toshort, self.pulse_recording)

        #
        # Build the GUI elements
        #
        self._build_gui(vbox)

        # Make GUI agree with command-line
        self.myform['average'].set_value(int(options.avg))
        self.myform['foldavg'].set_value(int(options.favg))

        # Make spectral averager agree with command line
        if options.avg != 1.0:
            self.scope.set_avg_alpha(float(1.0 / options.avg))
            self.scope.set_average(True)

        # set initial values

        if options.gain is None:
            # if no gain was specified, use the mid-point in dB
            g = self.subdev.gain_range()
            options.gain = float(g[0] + g[1]) / 2

        if options.freq is None:
            # if no freq was specified, use the mid-point
            r = self.subdev.freq_range()
            options.freq = float(r[0] + r[1]) / 2

        self.set_gain(options.gain)
        #self.set_volume(-10.0)

        if not (self.set_freq(options.freq)):
            self._set_status_msg("Failed to set initial frequency")

        self.myform['decim'].set_value(self.u.decim_rate())
        self.myform['fs@usb'].set_value(self.u.adc_freq() /
                                        self.u.decim_rate())
        self.myform['dbname'].set_value(self.subdev.name())
        self.myform['DM'].set_value(self.dm)
        self.myform['Doppler'].set_value(self.doppler)

        #
        # Start the timer that shows current LMST on the GUI
        #
        self.lmst_timer.Start(1000)
    def __init__(self, options):
        gr.top_block.__init__(self)
        self.options = options

        (dev_rate, channel_rate, audio_rate, channel_pass, channel_stop,
         demod) = demod_params[options.modulation]

        DEV = uhd_src(
            options.args,  # UHD device address
            options.spec,  # device subdev spec
            options.antenna,  # device antenna
            dev_rate,  # device sample rate
            options.gain,  # Receiver gain
            options.calibration)  # Frequency offset
        DEV.tune(options.frequency)

        if_rate = DEV.rate()
        channel_decim = int(if_rate // channel_rate)
        audio_decim = int(channel_rate // audio_rate)

        CHAN_taps = optfir.low_pass(
            1.0,  # Filter gain
            if_rate,  # Sample rate
            channel_pass,  # One sided modulation bandwidth
            channel_stop,  # One sided channel bandwidth
            0.1,  # Passband ripple
            60)  # Stopband attenuation

        CHAN = gr.freq_xlating_fir_filter_ccf(
            channel_decim,  # Decimation rate
            CHAN_taps,  # Filter taps
            0.0,  # Offset frequency
            if_rate)  # Sample rate

        RFSQL = gr.pwr_squelch_cc(
            options.rf_squelch,  # Power threshold
            125.0 / channel_rate,  # Time constant
            int(channel_rate / 20),  # 50ms rise/fall
            False)  # Zero, not gate output

        AGC = gr.agc_cc(
            1.0 / channel_rate,  # Time constant
            1.0,  # Reference power 
            1.0,  # Initial gain
            1.0)  # Maximum gain

        DEMOD = demod(channel_rate, audio_decim)

        # From RF to audio
        #self.connect(DEV, CHAN, RFSQL, AGC, DEMOD)
        self.connect(DEV, CHAN, DEMOD)

        # Optionally add CTCSS and RSAMP if needed
        tail = DEMOD
        if options.ctcss != None and options.ctcss > 60.0:
            CTCSS = gr.ctcss_squelch_ff(
                audio_rate,  # Sample rate
                options.ctcss)  # Squelch tone
            self.connect(DEMOD, CTCSS)
            tail = CTCSS

        if options.output_rate != audio_rate:
            out_lcm = gru.lcm(audio_rate, options.output_rate)
            out_interp = int(out_lcm // audio_rate)
            out_decim = int(out_lcm // options.output_rate)
            RSAMP = blks2.rational_resampler_fff(out_interp, out_decim)
            self.connect(tail, RSAMP)
            tail = RSAMP

        # Send to audio output device
        AUDIO = audio.sink(int(options.output_rate), options.audio_output)
        self.connect(tail, AUDIO)
    def __init__(self,
                 output_sample_rate=_def_output_sample_rate,
                 reverse=_def_reverse,
                 verbose=_def_verbose,
                 generator=transfer_function_tx,
                 dstar=False,
                 bt=_def_bt,
                 rc=None,
                 log=_def_log):
        """
	Hierarchical block for RRC-filtered P25 FM modulation.

	The input is a dibit (P25 symbol) stream (char, not packed) and the
	output is the float "C4FM" signal at baseband, suitable for application
        to an FM modulator stage

        Input is at the base symbol rate (4800), output sample rate is
        typically either 32000 (USRP TX chain) or 48000 (sound card)

	@param output_sample_rate: output sample rate
	@type output_sample_rate: integer
        @param reverse: reverse polarity flag
        @type reverse: bool
        @param verbose: Print information about modulator?
        @type verbose: bool
        @param debug: Print modulation data to files?
        @type debug: bool
	"""

        gr.hier_block2.__init__(
            self,
            "p25_c4fm_mod_bf",
            gr.io_signature(1, 1, gr.sizeof_char),  # Input signature
            gr.io_signature(1, 1, gr.sizeof_float))  # Output signature

        input_sample_rate = 4800  # P25 baseband symbol rate
        lcm = gru.lcm(input_sample_rate, output_sample_rate)
        self._interp_factor = int(lcm // input_sample_rate)
        self._decimation = int(lcm // output_sample_rate)

        self.dstar = dstar
        self.bt = bt

        if self.dstar:
            self.C2S = digital.chunks_to_symbols_bf([-1, 1], 1)
        else:
            mod_map = [1.0 / 3.0, 1.0, -(1.0 / 3.0), -1.0]
            self.C2S = digital.chunks_to_symbols_bf(mod_map)
        if reverse:
            self.polarity = blocks.multiply_const_ff(-1)
        else:
            self.polarity = blocks.multiply_const_ff(1)

        self.generator = generator

        assert rc is None or rc == 'rc' or rc == 'rrc'
        if rc:
            coeffs = filter.firdes.root_raised_cosine(1.0, output_sample_rate,
                                                      input_sample_rate, 0.2,
                                                      91)
        if rc == 'rc':
            coeffs = np.convolve(coeffs, coeffs)
        elif self.dstar:
            coeffs = gmsk_taps(sample_rate=output_sample_rate,
                               bt=self.bt).generate()
        elif not rc:
            coeffs = c4fm_taps(sample_rate=output_sample_rate,
                               generator=self.generator).generate()
        self.filter = filter.interp_fir_filter_fff(self._interp_factor, coeffs)

        if verbose:
            self._print_verbage()

        if log:
            self._setup_logging()

        self.connect(self, self.C2S, self.polarity, self.filter)
        if (self._decimation > 1):
            self.decimator = filter.rational_resampler_fff(1, self._decimation)
            self.connect(self.filter, self.decimator, self)
        else:
            self.connect(self.filter, self)