def __init__(self, dab_params, verbose=False, debug=False): """ Hierarchical block for OFDM modulation @param dab_params DAB parameter object (dab.parameters.dab_parameters) @param debug enables debug output to files """ dp = dab_params gr.hier_block2.__init__(self,"ofdm_mod", gr.io_signature2(2, 2, gr.sizeof_char*dp.num_carriers/4, gr.sizeof_char), # input signature gr.io_signature (1, 1, gr.sizeof_gr_complex)) # output signature # symbol mapping self.mapper = dab_swig.qpsk_mapper_vbc(dp.num_carriers) # add pilot symbol self.insert_pilot = dab_swig.ofdm_insert_pilot_vcc(dp.prn) # phase sum self.sum_phase = dab_swig.sum_phasor_trig_vcc(dp.num_carriers) # frequency interleaving self.interleave = dab_swig.frequency_interleaver_vcc(dp.frequency_interleaving_sequence_array) # add central carrier & move to middle self.move_and_insert_carrier = dab_swig.ofdm_move_and_insert_zero(dp.fft_length, dp.num_carriers) # ifft self.ifft = gr.fft_vcc(dp.fft_length, False, [], True) # cyclic prefixer self.prefixer = gr.ofdm_cyclic_prefixer(dp.fft_length, dp.symbol_length) # convert back to vectors self.s2v = gr.stream_to_vector(gr.sizeof_gr_complex, dp.symbol_length) # add null symbol self.insert_null = dab_swig.insert_null_symbol(dp.ns_length, dp.symbol_length) # # connect it all # # data self.connect((self,0), self.mapper, (self.insert_pilot,0), (self.sum_phase,0), self.interleave, self.move_and_insert_carrier, self.ifft, self.prefixer, self.s2v, (self.insert_null,0)) self.connect(self.insert_null, self) # control signal (frame start) self.connect((self,1), (self.insert_pilot,1), (self.sum_phase,1), (self.insert_null,1)) if debug: self.connect(self.mapper, gr.file_sink(gr.sizeof_gr_complex*dp.num_carriers, "debug/generated_signal_mapper.dat")) self.connect(self.insert_pilot, gr.file_sink(gr.sizeof_gr_complex*dp.num_carriers, "debug/generated_signal_insert_pilot.dat")) self.connect(self.sum_phase, gr.file_sink(gr.sizeof_gr_complex*dp.num_carriers, "debug/generated_signal_sum_phase.dat")) self.connect(self.interleave, gr.file_sink(gr.sizeof_gr_complex*dp.num_carriers, "debug/generated_signal_interleave.dat")) self.connect(self.move_and_insert_carrier, gr.file_sink(gr.sizeof_gr_complex*dp.fft_length, "debug/generated_signal_move_and_insert_carrier.dat")) self.connect(self.ifft, gr.file_sink(gr.sizeof_gr_complex*dp.fft_length, "debug/generated_signal_ifft.dat")) self.connect(self.prefixer, gr.file_sink(gr.sizeof_gr_complex, "debug/generated_signal_prefixer.dat")) self.connect(self.insert_null, gr.file_sink(gr.sizeof_gr_complex, "debug/generated_signal.dat"))
def __init__(self, dab_params, rx_params, verbose=False, debug=False): """ Hierarchical block for OFDM demodulation @param dab_params DAB parameter object (dab.parameters.dab_parameters) @param rx_params RX parameter object (dab.parameters.receiver_parameters) @param debug enables debug output to files @param verbose whether to produce verbose messages """ self.dp = dp = dab_params self.rp = rp = rx_params self.verbose = verbose if self.rp.softbits: gr.hier_block2.__init__(self,"ofdm_demod", gr.io_signature (1, 1, gr.sizeof_gr_complex), # input signature gr.io_signature2(2, 2, gr.sizeof_float*self.dp.num_carriers*2, gr.sizeof_char)) # output signature else: gr.hier_block2.__init__(self,"ofdm_demod", gr.io_signature (1, 1, gr.sizeof_gr_complex), # input signature gr.io_signature2(2, 2, gr.sizeof_char*self.dp.num_carriers/4, gr.sizeof_char)) # output signature # workaround for a problem that prevents connecting more than one block directly (see trac ticket #161) self.input = gr.kludge_copy(gr.sizeof_gr_complex) self.connect(self, self.input) # input filtering if self.rp.input_fft_filter: if verbose: print "--> RX filter enabled" lowpass_taps = gr.firdes_low_pass(1.0, # gain dp.sample_rate, # sampling rate rp.filt_bw, # cutoff frequency rp.filt_tb, # width of transition band gr.firdes.WIN_HAMMING) # Hamming window self.fft_filter = gr.fft_filter_ccc(1, lowpass_taps) # correct sample rate offset, if enabled if self.rp.autocorrect_sample_rate: if verbose: print "--> dynamic sample rate correction enabled" self.rate_detect_ns = detect_null.detect_null(dp.ns_length, False) self.rate_estimator = dab_swig.estimate_sample_rate_bf(dp.sample_rate, dp.frame_length) self.rate_prober = gr.probe_signal_f() self.connect(self.input, self.rate_detect_ns, self.rate_estimator, self.rate_prober) # self.resample = gr.fractional_interpolator_cc(0, 1) self.resample = dab_swig.fractional_interpolator_triggered_update_cc(0,1) self.connect(self.rate_detect_ns, (self.resample,1)) self.updater = Timer(0.1,self.update_correction) # self.updater = threading.Thread(target=self.update_correction) self.run_interpolater_update_thread = True self.updater.setDaemon(True) self.updater.start() else: self.run_interpolater_update_thread = False if self.rp.sample_rate_correction_factor != 1: if verbose: print "--> static sample rate correction enabled" self.resample = gr.fractional_interpolator_cc(0, self.rp.sample_rate_correction_factor) # timing and fine frequency synchronisation self.sync = ofdm_sync_dab2.ofdm_sync_dab(self.dp, self.rp, debug) # ofdm symbol sampler self.sampler = dab_swig.ofdm_sampler(dp.fft_length, dp.cp_length, dp.symbols_per_frame, rp.cp_gap) # fft for symbol vectors self.fft = gr.fft_vcc(dp.fft_length, True, [], True) # coarse frequency synchronisation self.cfs = dab_swig.ofdm_coarse_frequency_correct(dp.fft_length, dp.num_carriers, dp.cp_length) # diff phasor self.phase_diff = dab_swig.diff_phasor_vcc(dp.num_carriers) # remove pilot symbol self.remove_pilot = dab_swig.ofdm_remove_first_symbol_vcc(dp.num_carriers) # magnitude equalisation if self.rp.equalize_magnitude: if verbose: print "--> magnitude equalization enabled" self.equalizer = dab_swig.magnitude_equalizer_vcc(dp.num_carriers, rp.symbols_for_magnitude_equalization) # frequency deinterleaving self.deinterleave = dab_swig.frequency_interleaver_vcc(dp.frequency_deinterleaving_sequence_array) # symbol demapping self.demapper = dab_swig.qpsk_demapper_vcb(dp.num_carriers) # # connect everything # if self.rp.autocorrect_sample_rate or self.rp.sample_rate_correction_factor != 1: self.connect(self.input, self.resample) self.input2 = self.resample else: self.input2 = self.input if self.rp.input_fft_filter: self.connect(self.input2, self.fft_filter, self.sync) else: self.connect(self.input2, self.sync) # data stream self.connect((self.sync, 0), (self.sampler, 0), self.fft, (self.cfs, 0), self.phase_diff, (self.remove_pilot,0)) if self.rp.equalize_magnitude: self.connect((self.remove_pilot,0), (self.equalizer,0), self.deinterleave) else: self.connect((self.remove_pilot,0), self.deinterleave) if self.rp.softbits: if verbose: print "--> using soft bits" self.softbit_interleaver = dab_swig.complex_to_interleaved_float_vcf(self.dp.num_carriers) self.connect(self.deinterleave, self.softbit_interleaver, (self,0)) else: self.connect(self.deinterleave, self.demapper, (self,0)) # control stream self.connect((self.sync, 1), (self.sampler, 1), (self.cfs, 1), (self.remove_pilot,1)) if self.rp.equalize_magnitude: self.connect((self.remove_pilot,1), (self.equalizer,1), (self,1)) else: self.connect((self.remove_pilot,1), (self,1)) # calculate an estimate of the SNR self.phase_var_decim = gr.keep_one_in_n(gr.sizeof_gr_complex*self.dp.num_carriers, self.rp.phase_var_estimate_downsample) self.phase_var_arg = gr.complex_to_arg(dp.num_carriers) self.phase_var_v2s = gr.vector_to_stream(gr.sizeof_float, dp.num_carriers) self.phase_var_mod = dab_swig.modulo_ff(pi/2) self.phase_var_avg_mod = gr.iir_filter_ffd([rp.phase_var_estimate_alpha], [0,1-rp.phase_var_estimate_alpha]) self.phase_var_sub_avg = gr.sub_ff() self.phase_var_sqr = gr.multiply_ff() self.phase_var_avg = gr.iir_filter_ffd([rp.phase_var_estimate_alpha], [0,1-rp.phase_var_estimate_alpha]) self.probe_phase_var = gr.probe_signal_f() self.connect((self.remove_pilot,0), self.phase_var_decim, self.phase_var_arg, self.phase_var_v2s, self.phase_var_mod, (self.phase_var_sub_avg,0), (self.phase_var_sqr,0)) self.connect(self.phase_var_mod, self.phase_var_avg_mod, (self.phase_var_sub_avg,1)) self.connect(self.phase_var_sub_avg, (self.phase_var_sqr,1)) self.connect(self.phase_var_sqr, self.phase_var_avg, self.probe_phase_var) # measure processing rate self.measure_rate = dab_swig.measure_processing_rate(gr.sizeof_gr_complex, 2000000) self.connect(self.input, self.measure_rate) # debugging if debug: self.connect(self.fft, gr.file_sink(gr.sizeof_gr_complex*dp.fft_length, "debug/ofdm_after_fft.dat")) self.connect((self.cfs,0), gr.file_sink(gr.sizeof_gr_complex*dp.num_carriers, "debug/ofdm_after_cfs.dat")) self.connect(self.phase_diff, gr.file_sink(gr.sizeof_gr_complex*dp.num_carriers, "debug/ofdm_diff_phasor.dat")) self.connect((self.remove_pilot,0), gr.file_sink(gr.sizeof_gr_complex*dp.num_carriers, "debug/ofdm_pilot_removed.dat")) self.connect((self.remove_pilot,1), gr.file_sink(gr.sizeof_char, "debug/ofdm_after_cfs_trigger.dat")) self.connect(self.deinterleave, gr.file_sink(gr.sizeof_gr_complex*dp.num_carriers, "debug/ofdm_deinterleaved.dat")) if self.rp.equalize_magnitude: self.connect(self.equalizer, gr.file_sink(gr.sizeof_gr_complex*dp.num_carriers, "debug/ofdm_equalizer.dat")) if self.rp.softbits: self.connect(self.softbit_interleaver, gr.file_sink(gr.sizeof_float*dp.num_carriers*2, "debug/softbits.dat"))
