mirror of https://github.com/gnss-sdr/gnss-sdr
778 lines
40 KiB
C++
778 lines
40 KiB
C++
/*!
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* \file galileo_e5a_noncoherent_iq_acquisition_caf_cc.cc
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* \brief Adapts a PCPS acquisition block to an AcquisitionInterface for
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* Galileo E5a data and pilot Signals
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* \author Marc Sales, 2014. marcsales92(at)gmail.com
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* \based on work from:
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* <ul>
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* <li> Javier Arribas, 2011. jarribas(at)cttc.es
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* <li> Luis Esteve, 2012. luis(at)epsilon-formacion.com
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* <li> Marc Molina, 2013. marc.molina.pena@gmail.com
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* </ul>
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*
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* -----------------------------------------------------------------------------
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*
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* GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
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* This file is part of GNSS-SDR.
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*
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* Copyright (C) 2010-2020 (see AUTHORS file for a list of contributors)
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* SPDX-License-Identifier: GPL-3.0-or-later
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*
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* -----------------------------------------------------------------------------
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*/
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#include "galileo_e5a_noncoherent_iq_acquisition_caf_cc.h"
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#include "MATH_CONSTANTS.h"
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#include <glog/logging.h>
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#include <gnuradio/io_signature.h>
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#include <volk/volk.h>
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#include <volk_gnsssdr/volk_gnsssdr.h>
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#include <algorithm>
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#include <array>
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#include <exception>
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#include <sstream>
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galileo_e5a_noncoherentIQ_acquisition_caf_cc_sptr galileo_e5a_noncoherentIQ_make_acquisition_caf_cc(
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unsigned int sampled_ms,
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unsigned int max_dwells,
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unsigned int doppler_max, int64_t fs_in,
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int samples_per_ms, int samples_per_code,
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bool bit_transition_flag,
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bool dump,
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const std::string &dump_filename,
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bool both_signal_components_,
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int CAF_window_hz_,
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int Zero_padding_,
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bool enable_monitor_output)
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{
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return galileo_e5a_noncoherentIQ_acquisition_caf_cc_sptr(
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new galileo_e5a_noncoherentIQ_acquisition_caf_cc(sampled_ms, max_dwells, doppler_max, fs_in, samples_per_ms,
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samples_per_code, bit_transition_flag, dump, dump_filename, both_signal_components_, CAF_window_hz_, Zero_padding_, enable_monitor_output));
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}
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galileo_e5a_noncoherentIQ_acquisition_caf_cc::galileo_e5a_noncoherentIQ_acquisition_caf_cc(
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unsigned int sampled_ms,
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unsigned int max_dwells,
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unsigned int doppler_max,
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int64_t fs_in,
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int samples_per_ms,
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int samples_per_code,
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bool bit_transition_flag,
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bool dump,
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const std::string &dump_filename,
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bool both_signal_components_,
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int CAF_window_hz_,
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int Zero_padding_,
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bool enable_monitor_output)
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: gr::block("galileo_e5a_noncoherentIQ_acquisition_caf_cc",
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gr::io_signature::make(1, 1, sizeof(gr_complex)),
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gr::io_signature::make(0, 1, sizeof(Gnss_Synchro))),
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d_dump_filename(dump_filename),
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d_gnss_synchro(nullptr),
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d_fs_in(fs_in),
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d_sample_counter(0ULL),
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d_threshold(0),
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d_doppler_freq(0),
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d_mag(0),
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d_input_power(0.0),
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d_test_statistics(0),
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d_state(0),
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d_samples_per_ms(samples_per_ms),
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d_samples_per_code(samples_per_code),
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d_CAF_window_hz(CAF_window_hz_),
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d_buffer_count(0),
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d_doppler_resolution(0),
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d_doppler_max(static_cast<int>(doppler_max)),
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d_doppler_step(250),
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d_fft_size(static_cast<int>(sampled_ms) * d_samples_per_ms),
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d_num_doppler_bins(0),
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d_gr_stream_buffer(0),
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d_channel(0),
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d_max_dwells(max_dwells),
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d_well_count(0),
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d_code_phase(0),
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d_bit_transition_flag(bit_transition_flag),
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d_active(false),
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d_dump(dump),
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d_both_signal_components(both_signal_components_),
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d_enable_monitor_output(enable_monitor_output)
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{
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this->message_port_register_out(pmt::mp("events"));
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if (Zero_padding_ > 0)
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{
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d_sampled_ms = 1;
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}
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else
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{
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d_sampled_ms = sampled_ms;
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}
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d_inbuffer = std::vector<gr_complex>(d_fft_size);
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d_fft_code_I_A = std::vector<gr_complex>(d_fft_size);
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d_magnitudeIA = std::vector<float>(d_fft_size);
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if (d_both_signal_components == true)
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{
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d_fft_code_Q_A = std::vector<gr_complex>(d_fft_size);
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d_magnitudeQA = std::vector<float>(d_fft_size);
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}
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// IF COHERENT INTEGRATION TIME > 1
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if (d_sampled_ms > 1)
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{
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d_fft_code_I_B = std::vector<gr_complex>(d_fft_size);
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d_magnitudeIB = std::vector<float>(d_fft_size);
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if (d_both_signal_components == true)
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{
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d_fft_code_Q_B = std::vector<gr_complex>(d_fft_size);
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d_magnitudeQB = std::vector<float>(d_fft_size);
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}
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}
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d_fft_if = gnss_fft_fwd_make_unique(d_fft_size);
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d_ifft = gnss_fft_rev_make_unique(d_fft_size);
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}
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galileo_e5a_noncoherentIQ_acquisition_caf_cc::~galileo_e5a_noncoherentIQ_acquisition_caf_cc()
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{
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try
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{
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if (d_dump)
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{
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d_dump_file.close();
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}
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}
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catch (const std::ofstream::failure &e)
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{
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std::cerr << "Problem closing Acquisition dump file: " << d_dump_filename << '\n';
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}
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catch (const std::exception &e)
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{
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std::cerr << e.what() << '\n';
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}
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}
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void galileo_e5a_noncoherentIQ_acquisition_caf_cc::set_local_code(std::complex<float> *codeI, std::complex<float> *codeQ)
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{
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// DATA SIGNAL
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// Three replicas of data primary code. CODE A: (1,1,1)
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std::copy(codeI, codeI + d_fft_size, d_fft_if->get_inbuf());
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d_fft_if->execute(); // We need the FFT of local code
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// Conjugate the local code
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volk_32fc_conjugate_32fc(d_fft_code_I_A.data(), d_fft_if->get_outbuf(), d_fft_size);
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// SAME FOR PILOT SIGNAL
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if (d_both_signal_components == true)
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{
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// Three replicas of pilot primary code. CODE A: (1,1,1)
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std::copy(codeQ, codeQ + d_fft_size, d_fft_if->get_inbuf());
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d_fft_if->execute(); // We need the FFT of local code
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// Conjugate the local code
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volk_32fc_conjugate_32fc(d_fft_code_Q_A.data(), d_fft_if->get_outbuf(), d_fft_size);
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}
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// IF INTEGRATION TIME > 1 code, we need to evaluate the other possible combination
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// Note: max integration time allowed = 3ms (dealt in adapter)
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if (d_sampled_ms > 1)
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{
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// DATA CODE B: First replica is inverted (0,1,1)
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#if VOLK_EQUAL_OR_GREATER_31
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auto minus_one = gr_complex(-1, 0);
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volk_32fc_s32fc_multiply2_32fc(&(d_fft_if->get_inbuf())[0],
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&codeI[0], &minus_one,
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d_samples_per_code);
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#else
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volk_32fc_s32fc_multiply_32fc(&(d_fft_if->get_inbuf())[0],
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&codeI[0], gr_complex(-1, 0),
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d_samples_per_code);
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#endif
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d_fft_if->execute(); // We need the FFT of local code
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// Conjugate the local code
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volk_32fc_conjugate_32fc(d_fft_code_I_B.data(), d_fft_if->get_outbuf(), d_fft_size);
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if (d_both_signal_components == true)
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{
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// PILOT CODE B: First replica is inverted (0,1,1)
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#if VOLK_EQUAL_OR_GREATER_31
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auto minus_one = gr_complex(-1, 0);
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volk_32fc_s32fc_multiply2_32fc(&(d_fft_if->get_inbuf())[0],
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&codeQ[0], &minus_one,
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d_samples_per_code);
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#else
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volk_32fc_s32fc_multiply_32fc(&(d_fft_if->get_inbuf())[0],
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&codeQ[0], gr_complex(-1, 0),
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d_samples_per_code);
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#endif
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d_fft_if->execute(); // We need the FFT of local code
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// Conjugate the local code
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volk_32fc_conjugate_32fc(d_fft_code_Q_B.data(), d_fft_if->get_outbuf(), d_fft_size);
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}
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}
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}
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void galileo_e5a_noncoherentIQ_acquisition_caf_cc::init()
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{
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d_gnss_synchro->Flag_valid_acquisition = false;
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d_gnss_synchro->Flag_valid_symbol_output = false;
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d_gnss_synchro->Flag_valid_pseudorange = false;
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d_gnss_synchro->Flag_valid_word = false;
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d_gnss_synchro->Acq_delay_samples = 0.0;
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d_gnss_synchro->Acq_doppler_hz = 0.0;
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d_gnss_synchro->Acq_doppler_step = 0U;
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d_gnss_synchro->Acq_samplestamp_samples = 0ULL;
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d_mag = 0.0;
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d_input_power = 0.0;
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// Count the number of bins
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d_num_doppler_bins = 0;
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for (int doppler = -d_doppler_max;
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doppler <= d_doppler_max;
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doppler += d_doppler_step)
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{
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d_num_doppler_bins++;
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}
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// Create the carrier Doppler wipeoff signals
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d_grid_doppler_wipeoffs = std::vector<std::vector<gr_complex>>(d_num_doppler_bins, std::vector<gr_complex>(d_fft_size));
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for (int doppler_index = 0; doppler_index < d_num_doppler_bins; doppler_index++)
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{
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int doppler = -d_doppler_max + d_doppler_step * doppler_index;
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float phase_step_rad = static_cast<float>(TWO_PI) * static_cast<float>(doppler) / static_cast<float>(d_fs_in);
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std::array<float, 1> _phase{};
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volk_gnsssdr_s32f_sincos_32fc(d_grid_doppler_wipeoffs[doppler_index].data(), -phase_step_rad, _phase.data(), d_fft_size);
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}
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/* CAF Filtering to resolve doppler ambiguity. Phase and quadrature must be processed
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* separately before non-coherent integration */
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if (d_CAF_window_hz > 0)
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{
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d_CAF_vector = std::vector<float>(d_num_doppler_bins);
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d_CAF_vector_I = std::vector<float>(d_num_doppler_bins);
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if (d_both_signal_components == true)
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{
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d_CAF_vector_Q = std::vector<float>(d_num_doppler_bins);
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}
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}
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}
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void galileo_e5a_noncoherentIQ_acquisition_caf_cc::set_state(int state)
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{
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d_state = state;
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if (d_state == 1)
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{
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d_gnss_synchro->Acq_delay_samples = 0.0;
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d_gnss_synchro->Acq_doppler_hz = 0.0;
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d_gnss_synchro->Acq_samplestamp_samples = 0ULL;
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d_gnss_synchro->Acq_doppler_step = 0U;
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d_well_count = 0;
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d_mag = 0.0;
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d_input_power = 0.0;
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d_test_statistics = 0.0;
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}
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else if (d_state == 0)
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{
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}
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else
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{
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LOG(ERROR) << "State can only be set to 0 or 1";
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}
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}
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int galileo_e5a_noncoherentIQ_acquisition_caf_cc::general_work(int noutput_items __attribute__((unused)),
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gr_vector_int &ninput_items, gr_vector_const_void_star &input_items,
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gr_vector_void_star &output_items)
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{
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/*
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* By J.Arribas, L.Esteve, M.Molina and M.Sales
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* Acquisition strategy (Kay Borre book + CFAR threshold):
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* 1. Compute the input signal power estimation
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* 2. Doppler serial search loop
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* 3. Perform the FFT-based circular convolution (parallel time search)
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* 4. OPTIONAL: CAF filter to avoid doppler ambiguity
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* 5. Record the maximum peak and the associated synchronization parameters
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* 6. Compute the test statistics and compare to the threshold
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* 7. Declare positive or negative acquisition using a message port
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*/
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int acquisition_message = -1; // 0=STOP_CHANNEL 1=ACQ_SUCCEES 2=ACQ_FAIL
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int return_value = 0; // 0=Produces no Gnss_Synchro objects
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/* States: 0 Stop Channel
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* 1 Load the buffer until it reaches fft_size
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* 2 Acquisition algorithm
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* 3 Positive acquisition
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* 4 Negative acquisition
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*/
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switch (d_state)
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{
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case 0:
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{
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if (d_active)
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{
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// restart acquisition variables
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d_gnss_synchro->Acq_delay_samples = 0.0;
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d_gnss_synchro->Acq_doppler_hz = 0.0;
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d_gnss_synchro->Acq_samplestamp_samples = 0ULL;
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d_gnss_synchro->Acq_doppler_step = 0U;
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d_well_count = 0;
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d_mag = 0.0;
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d_input_power = 0.0;
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d_test_statistics = 0.0;
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d_state = 1;
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}
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d_sample_counter += static_cast<uint64_t>(ninput_items[0]); // sample counter
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consume_each(ninput_items[0]);
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break;
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}
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case 1:
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{
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const auto *in = reinterpret_cast<const gr_complex *>(input_items[0]); // Get the input samples pointer
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int buff_increment;
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if ((ninput_items[0] + d_buffer_count) <= d_fft_size)
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{
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buff_increment = ninput_items[0];
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}
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else
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{
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buff_increment = d_fft_size - d_buffer_count;
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}
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std::copy(in, in + buff_increment, d_inbuffer.begin() + d_buffer_count);
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// If buffer will be full in next iteration
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if (d_buffer_count >= static_cast<int>(d_fft_size - d_gr_stream_buffer))
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{
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d_state = 2;
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}
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d_buffer_count += buff_increment;
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d_sample_counter += static_cast<uint64_t>(buff_increment); // sample counter
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consume_each(buff_increment);
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break;
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}
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case 2:
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{
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// Fill last part of the buffer and reset counter
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const auto *in = reinterpret_cast<const gr_complex *>(input_items[0]); // Get the input samples pointer
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if (d_buffer_count < d_fft_size)
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{
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std::copy(in, in + (d_fft_size - d_buffer_count), d_inbuffer.begin() + d_buffer_count);
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}
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d_sample_counter += static_cast<uint64_t>(d_fft_size - d_buffer_count); // sample counter
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// initialize acquisition algorithm
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int doppler;
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uint32_t indext = 0;
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uint32_t indext_IA = 0;
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uint32_t indext_IB = 0;
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uint32_t indext_QA = 0;
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uint32_t indext_QB = 0;
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float magt = 0.0;
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float magt_IA = 0.0;
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float magt_IB = 0.0;
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float magt_QA = 0.0;
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float magt_QB = 0.0;
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float fft_normalization_factor = static_cast<float>(d_fft_size) * static_cast<float>(d_fft_size);
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d_input_power = 0.0;
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d_mag = 0.0;
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d_well_count++;
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DLOG(INFO) << "Channel: " << d_channel
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<< " , doing acquisition of satellite: " << d_gnss_synchro->System << " " << d_gnss_synchro->PRN
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<< " ,sample stamp: " << d_sample_counter << ", threshold: "
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<< d_threshold << ", doppler_max: " << d_doppler_max
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<< ", doppler_step: " << d_doppler_step;
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// 1- Compute the input signal power estimation
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volk_32fc_magnitude_squared_32f(d_magnitudeIA.data(), d_inbuffer.data(), d_fft_size);
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volk_32f_accumulator_s32f(&d_input_power, d_magnitudeIA.data(), d_fft_size);
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d_input_power /= static_cast<float>(d_fft_size);
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// 2- Doppler frequency search loop
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for (int doppler_index = 0; doppler_index < d_num_doppler_bins; doppler_index++)
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{
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// doppler search steps
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doppler = -static_cast<int>(d_doppler_max) + d_doppler_step * doppler_index;
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volk_32fc_x2_multiply_32fc(d_fft_if->get_inbuf(), d_inbuffer.data(),
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d_grid_doppler_wipeoffs[doppler_index].data(), d_fft_size);
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// 3- Perform the FFT-based convolution (parallel time search)
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// Compute the FFT of the carrier wiped--off incoming signal
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d_fft_if->execute();
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// CODE IA
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// Multiply carrier wiped--off, Fourier transformed incoming signal
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// with the local FFT'd code reference using SIMD operations with VOLK library
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volk_32fc_x2_multiply_32fc(d_ifft->get_inbuf(),
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d_fft_if->get_outbuf(), d_fft_code_I_A.data(), d_fft_size);
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// compute the inverse FFT
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d_ifft->execute();
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// Search maximum
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volk_32fc_magnitude_squared_32f(d_magnitudeIA.data(), d_ifft->get_outbuf(), d_fft_size);
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volk_gnsssdr_32f_index_max_32u(&indext_IA, d_magnitudeIA.data(), d_fft_size);
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// Normalize the maximum value to correct the scale factor introduced by FFTW
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magt_IA = d_magnitudeIA[indext_IA] / (fft_normalization_factor * fft_normalization_factor);
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if (d_both_signal_components == true)
|
|
{
|
|
// REPEAT FOR ALL CODES. CODE_QA
|
|
volk_32fc_x2_multiply_32fc(d_ifft->get_inbuf(),
|
|
d_fft_if->get_outbuf(), d_fft_code_Q_A.data(), d_fft_size);
|
|
d_ifft->execute();
|
|
volk_32fc_magnitude_squared_32f(d_magnitudeQA.data(), d_ifft->get_outbuf(), d_fft_size);
|
|
volk_gnsssdr_32f_index_max_32u(&indext_QA, d_magnitudeQA.data(), d_fft_size);
|
|
magt_QA = d_magnitudeQA[indext_QA] / (fft_normalization_factor * fft_normalization_factor);
|
|
}
|
|
if (d_sampled_ms > 1) // If Integration time > 1 code
|
|
{
|
|
// REPEAT FOR ALL CODES. CODE_IB
|
|
volk_32fc_x2_multiply_32fc(d_ifft->get_inbuf(),
|
|
d_fft_if->get_outbuf(), d_fft_code_I_B.data(), d_fft_size);
|
|
d_ifft->execute();
|
|
volk_32fc_magnitude_squared_32f(d_magnitudeIB.data(), d_ifft->get_outbuf(), d_fft_size);
|
|
volk_gnsssdr_32f_index_max_32u(&indext_IB, d_magnitudeIB.data(), d_fft_size);
|
|
magt_IB = d_magnitudeIB[indext_IB] / (fft_normalization_factor * fft_normalization_factor);
|
|
|
|
if (d_both_signal_components == true)
|
|
{
|
|
// REPEAT FOR ALL CODES. CODE_QB
|
|
volk_32fc_x2_multiply_32fc(d_ifft->get_inbuf(),
|
|
d_fft_if->get_outbuf(), d_fft_code_Q_B.data(), d_fft_size);
|
|
d_ifft->execute();
|
|
volk_32fc_magnitude_squared_32f(d_magnitudeQB.data(), d_ifft->get_outbuf(), d_fft_size);
|
|
volk_gnsssdr_32f_index_max_32u(&indext_QB, d_magnitudeQB.data(), d_fft_size);
|
|
magt_QB = d_magnitudeIB[indext_QB] / (fft_normalization_factor * fft_normalization_factor);
|
|
}
|
|
}
|
|
|
|
// Integrate noncoherently the two best combinations (I² + Q²)
|
|
// and store the result in the I channel.
|
|
// If CAF filter to resolve doppler ambiguity is needed,
|
|
// peak is stored before non-coherent integration.
|
|
if (d_sampled_ms > 1) // T_integration > 1 code
|
|
{
|
|
if (magt_IA >= magt_IB)
|
|
{
|
|
if (d_CAF_window_hz > 0)
|
|
{
|
|
d_CAF_vector_I[doppler_index] = d_magnitudeIA[indext_IA];
|
|
}
|
|
if (d_both_signal_components)
|
|
{
|
|
// Integrate non-coherently I+Q
|
|
if (magt_QA >= magt_QB)
|
|
{
|
|
if (d_CAF_window_hz > 0)
|
|
{
|
|
d_CAF_vector_Q[doppler_index] = d_magnitudeQA[indext_QA];
|
|
}
|
|
for (int i = 0; i < d_fft_size; i++)
|
|
{
|
|
d_magnitudeIA[i] += d_magnitudeQA[i];
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (d_CAF_window_hz > 0)
|
|
{
|
|
d_CAF_vector_Q[doppler_index] = d_magnitudeQB[indext_QB];
|
|
}
|
|
for (int i = 0; i < d_fft_size; i++)
|
|
{
|
|
d_magnitudeIA[i] += d_magnitudeQB[i];
|
|
}
|
|
}
|
|
}
|
|
volk_gnsssdr_32f_index_max_32u(&indext, d_magnitudeIA.data(), d_fft_size);
|
|
magt = d_magnitudeIA[indext] / (fft_normalization_factor * fft_normalization_factor);
|
|
}
|
|
else
|
|
{
|
|
if (d_CAF_window_hz > 0)
|
|
{
|
|
d_CAF_vector_I[doppler_index] = d_magnitudeIB[indext_IB];
|
|
}
|
|
if (d_both_signal_components)
|
|
{
|
|
// Integrate non-coherently I+Q
|
|
if (magt_QA >= magt_QB)
|
|
{
|
|
if (d_CAF_window_hz > 0)
|
|
{
|
|
d_CAF_vector_Q[doppler_index] = d_magnitudeQA[indext_QA];
|
|
}
|
|
for (int i = 0; i < d_fft_size; i++)
|
|
{
|
|
d_magnitudeIB[i] += d_magnitudeQA[i];
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (d_CAF_window_hz > 0)
|
|
{
|
|
d_CAF_vector_Q[doppler_index] = d_magnitudeQB[indext_QB];
|
|
}
|
|
for (int i = 0; i < d_fft_size; i++)
|
|
{
|
|
d_magnitudeIB[i] += d_magnitudeQB[i];
|
|
}
|
|
}
|
|
}
|
|
volk_gnsssdr_32f_index_max_32u(&indext, d_magnitudeIB.data(), d_fft_size);
|
|
magt = d_magnitudeIB[indext] / (fft_normalization_factor * fft_normalization_factor);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (d_CAF_window_hz > 0)
|
|
{
|
|
d_CAF_vector_I[doppler_index] = d_magnitudeIA[indext_IA];
|
|
}
|
|
if (d_both_signal_components)
|
|
{
|
|
if (d_CAF_window_hz > 0)
|
|
{
|
|
d_CAF_vector_Q[doppler_index] = d_magnitudeQA[indext_QA];
|
|
}
|
|
// NON-Coherent integration of only 1 code
|
|
for (int i = 0; i < d_fft_size; i++)
|
|
{
|
|
d_magnitudeIA[i] += d_magnitudeQA[i];
|
|
}
|
|
}
|
|
volk_gnsssdr_32f_index_max_32u(&indext, d_magnitudeIA.data(), d_fft_size);
|
|
magt = d_magnitudeIA[indext] / (fft_normalization_factor * fft_normalization_factor);
|
|
}
|
|
|
|
// 4- record the maximum peak and the associated synchronization parameters
|
|
if (d_mag < magt)
|
|
{
|
|
d_mag = magt;
|
|
// In case that d_bit_transition_flag = true, we compare the potentially
|
|
// new maximum test statistics (d_mag/d_input_power) with the value in
|
|
// d_test_statistics. When the second dwell is being processed, the value
|
|
// of d_mag/d_input_power could be lower than d_test_statistics (i.e,
|
|
// the maximum test statistics in the previous dwell is greater than
|
|
// current d_mag/d_input_power). Note that d_test_statistics is not
|
|
// restarted between consecutive dwells in multidwell operation.
|
|
if (d_test_statistics < (d_mag / d_input_power) || !d_bit_transition_flag)
|
|
{
|
|
d_gnss_synchro->Acq_delay_samples = static_cast<double>(indext % d_samples_per_code);
|
|
d_gnss_synchro->Acq_doppler_hz = static_cast<double>(doppler);
|
|
d_gnss_synchro->Acq_samplestamp_samples = d_sample_counter;
|
|
d_gnss_synchro->Acq_doppler_step = d_doppler_step;
|
|
// 5- Compute the test statistics and compare to the threshold
|
|
d_test_statistics = d_mag / d_input_power;
|
|
}
|
|
}
|
|
|
|
// Record results to file if required
|
|
if (d_dump)
|
|
{
|
|
std::stringstream filename;
|
|
std::streamsize n = sizeof(float) * (d_fft_size); // noncomplex file write
|
|
filename.str("");
|
|
filename << "../data/test_statistics_E5a_sat_"
|
|
<< d_gnss_synchro->PRN << "_doppler_" << doppler << ".dat";
|
|
d_dump_file.open(filename.str().c_str(), std::ios::out | std::ios::binary);
|
|
if (d_sampled_ms > 1) // If integration time > 1 code
|
|
{
|
|
if (magt_IA >= magt_IB)
|
|
{
|
|
d_dump_file.write(reinterpret_cast<char *>(d_magnitudeIA.data()), n);
|
|
}
|
|
else
|
|
{
|
|
d_dump_file.write(reinterpret_cast<char *>(d_magnitudeIB.data()), n);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
d_dump_file.write(reinterpret_cast<char *>(d_magnitudeIA.data()), n);
|
|
}
|
|
d_dump_file.close();
|
|
}
|
|
}
|
|
// std::cout << "d_mag " << d_mag << ".d_sample_counter " << d_sample_counter << ". acq delay " << d_gnss_synchro->Acq_delay_samples<< " indext "<< indext << '\n';
|
|
// 6 OPTIONAL: CAF filter to avoid Doppler ambiguity in bit transition.
|
|
if (d_CAF_window_hz > 0)
|
|
{
|
|
int CAF_bins_half;
|
|
std::array<float, 1> accum{};
|
|
CAF_bins_half = d_CAF_window_hz / (2 * d_doppler_step);
|
|
float weighting_factor;
|
|
weighting_factor = 0.5F / static_cast<float>(CAF_bins_half);
|
|
// weighting_factor = 0;
|
|
// std::cout << "weighting_factor " << weighting_factor << '\n';
|
|
// Initialize first iterations
|
|
for (int doppler_index = 0; doppler_index < CAF_bins_half; doppler_index++)
|
|
{
|
|
d_CAF_vector[doppler_index] = 0;
|
|
for (int i = 0; i < CAF_bins_half + doppler_index + 1; i++)
|
|
{
|
|
d_CAF_vector[doppler_index] += d_CAF_vector_I[i] * (1.0F - weighting_factor * static_cast<float>((doppler_index - i)));
|
|
}
|
|
d_CAF_vector[doppler_index] /= 1.0F + static_cast<float>(CAF_bins_half + doppler_index) - weighting_factor * static_cast<float>(CAF_bins_half) * ((static_cast<float>(CAF_bins_half) + 1.0F) / 2.0F) - weighting_factor * static_cast<float>(doppler_index) * (static_cast<float>(doppler_index) + 1.0F) / 2.0F; // triangles = [n*(n+1)/2]
|
|
if (d_both_signal_components)
|
|
{
|
|
accum[0] = 0;
|
|
for (int i = 0; i < CAF_bins_half + doppler_index + 1; i++)
|
|
{
|
|
accum[0] += d_CAF_vector_Q[i] * (1.0F - weighting_factor * static_cast<float>(abs(doppler_index - i)));
|
|
}
|
|
accum[0] /= 1.0F + static_cast<float>(CAF_bins_half + doppler_index) - weighting_factor * static_cast<float>(CAF_bins_half) * static_cast<float>(CAF_bins_half + 1) / 2.0F - weighting_factor * static_cast<float>(doppler_index) * static_cast<float>(doppler_index + 1) / 2.0F; // triangles = [n*(n+1)/2]
|
|
d_CAF_vector[doppler_index] += accum[0];
|
|
}
|
|
}
|
|
// Body loop
|
|
for (int doppler_index = CAF_bins_half; doppler_index < d_num_doppler_bins - CAF_bins_half; doppler_index++)
|
|
{
|
|
d_CAF_vector[doppler_index] = 0;
|
|
for (int i = doppler_index - CAF_bins_half; i < doppler_index + CAF_bins_half + 1; i++)
|
|
{
|
|
d_CAF_vector[doppler_index] += d_CAF_vector_I[i] * (1.0F - weighting_factor * static_cast<float>((doppler_index - i)));
|
|
}
|
|
d_CAF_vector[doppler_index] /= 1.0F + 2.0F * static_cast<float>(CAF_bins_half) - 2.0F * weighting_factor * static_cast<float>(CAF_bins_half) * static_cast<float>(CAF_bins_half + 1) / 2.0F;
|
|
if (d_both_signal_components)
|
|
{
|
|
accum[0] = 0;
|
|
for (int i = doppler_index - CAF_bins_half; i < doppler_index + CAF_bins_half + 1; i++)
|
|
{
|
|
accum[0] += d_CAF_vector_Q[i] * (1 - weighting_factor * static_cast<float>((doppler_index - i)));
|
|
}
|
|
accum[0] /= 1.0F + 2.0F * static_cast<float>(CAF_bins_half) - 2.0F * weighting_factor * static_cast<float>(CAF_bins_half) * static_cast<float>(CAF_bins_half + 1) / 2.0F;
|
|
d_CAF_vector[doppler_index] += accum[0];
|
|
}
|
|
}
|
|
// Final iterations
|
|
for (int doppler_index = d_num_doppler_bins - CAF_bins_half; doppler_index < static_cast<int>(d_num_doppler_bins); doppler_index++)
|
|
{
|
|
d_CAF_vector[doppler_index] = 0;
|
|
for (int i = doppler_index - CAF_bins_half; i < static_cast<int>(d_num_doppler_bins); i++)
|
|
{
|
|
d_CAF_vector[doppler_index] += d_CAF_vector_I[i] * (1.0F - weighting_factor * static_cast<float>(abs(doppler_index - i)));
|
|
}
|
|
d_CAF_vector[doppler_index] /= 1.0F + static_cast<float>(CAF_bins_half) + static_cast<float>(d_num_doppler_bins - doppler_index - 1) - weighting_factor * static_cast<float>(CAF_bins_half) * (static_cast<float>(CAF_bins_half) + 1.0F) / 2.0F - weighting_factor * (d_num_doppler_bins - doppler_index - 1) * static_cast<float>(d_num_doppler_bins - doppler_index) / 2.0F;
|
|
if (d_both_signal_components)
|
|
{
|
|
accum[0] = 0;
|
|
for (int i = doppler_index - CAF_bins_half; i < static_cast<int>(d_num_doppler_bins); i++)
|
|
{
|
|
accum[0] += d_CAF_vector_Q[i] * (1.0F - weighting_factor * static_cast<float>(abs(doppler_index - i)));
|
|
}
|
|
accum[0] /= static_cast<float>(1.0F + static_cast<float>(CAF_bins_half) + static_cast<float>(d_num_doppler_bins - doppler_index - 1) - weighting_factor * static_cast<float>(CAF_bins_half) * static_cast<float>(CAF_bins_half + 1.0) / 2.0 - weighting_factor * static_cast<float>(d_num_doppler_bins - doppler_index - 1) * static_cast<float>(d_num_doppler_bins - doppler_index) / 2.0);
|
|
d_CAF_vector[doppler_index] += accum[0];
|
|
}
|
|
}
|
|
|
|
// Recompute the maximum doppler peak
|
|
volk_gnsssdr_32f_index_max_32u(&indext, d_CAF_vector.data(), d_num_doppler_bins);
|
|
doppler = -d_doppler_max + d_doppler_step * static_cast<int>(indext);
|
|
d_gnss_synchro->Acq_doppler_hz = static_cast<double>(doppler);
|
|
// Dump if required, appended at the end of the file
|
|
if (d_dump)
|
|
{
|
|
std::stringstream filename;
|
|
std::streamsize n = sizeof(float) * (d_num_doppler_bins); // noncomplex file write
|
|
filename.str("");
|
|
filename << "../data/test_statistics_E5a_sat_" << d_gnss_synchro->PRN << "_CAF.dat";
|
|
d_dump_file.open(filename.str().c_str(), std::ios::out | std::ios::binary);
|
|
d_dump_file.write(reinterpret_cast<char *>(d_CAF_vector.data()), n);
|
|
d_dump_file.close();
|
|
}
|
|
}
|
|
|
|
if (d_well_count == d_max_dwells)
|
|
{
|
|
if (d_test_statistics > d_threshold)
|
|
{
|
|
d_state = 3; // Positive acquisition
|
|
}
|
|
else
|
|
{
|
|
d_state = 4; // Negative acquisition
|
|
}
|
|
}
|
|
else
|
|
{
|
|
d_state = 1;
|
|
}
|
|
|
|
consume_each(d_fft_size - d_buffer_count);
|
|
d_buffer_count = 0;
|
|
break;
|
|
}
|
|
case 3:
|
|
{
|
|
// 7.1- Declare positive acquisition using a message port
|
|
DLOG(INFO) << "positive acquisition";
|
|
DLOG(INFO) << "satellite " << d_gnss_synchro->System << " " << d_gnss_synchro->PRN;
|
|
DLOG(INFO) << "sample_stamp " << d_sample_counter;
|
|
DLOG(INFO) << "test statistics value " << d_test_statistics;
|
|
DLOG(INFO) << "test statistics threshold " << d_threshold;
|
|
DLOG(INFO) << "code phase " << d_gnss_synchro->Acq_delay_samples;
|
|
DLOG(INFO) << "doppler " << d_gnss_synchro->Acq_doppler_hz;
|
|
DLOG(INFO) << "magnitude " << d_mag;
|
|
DLOG(INFO) << "input signal power " << d_input_power;
|
|
|
|
d_active = false;
|
|
d_state = 0;
|
|
|
|
acquisition_message = 1;
|
|
this->message_port_pub(pmt::mp("events"), pmt::from_long(acquisition_message));
|
|
d_sample_counter += static_cast<uint64_t>(ninput_items[0]); // sample counter
|
|
consume_each(ninput_items[0]);
|
|
|
|
// Copy and push current Gnss_Synchro to monitor queue
|
|
if (d_enable_monitor_output)
|
|
{
|
|
auto **out = reinterpret_cast<Gnss_Synchro **>(&output_items[0]);
|
|
Gnss_Synchro current_synchro_data = Gnss_Synchro();
|
|
current_synchro_data = *d_gnss_synchro;
|
|
*out[0] = std::move(current_synchro_data);
|
|
return_value = 1; // Number of Gnss_Synchro objects produced
|
|
}
|
|
|
|
break;
|
|
}
|
|
case 4:
|
|
{
|
|
// 7.2- Declare negative acquisition using a message port
|
|
DLOG(INFO) << "negative acquisition";
|
|
DLOG(INFO) << "satellite " << d_gnss_synchro->System << " " << d_gnss_synchro->PRN;
|
|
DLOG(INFO) << "sample_stamp " << d_sample_counter;
|
|
DLOG(INFO) << "test statistics value " << d_test_statistics;
|
|
DLOG(INFO) << "test statistics threshold " << d_threshold;
|
|
DLOG(INFO) << "code phase " << d_gnss_synchro->Acq_delay_samples;
|
|
DLOG(INFO) << "doppler " << d_gnss_synchro->Acq_doppler_hz;
|
|
DLOG(INFO) << "magnitude " << d_mag;
|
|
DLOG(INFO) << "input signal power " << d_input_power;
|
|
|
|
d_active = false;
|
|
d_state = 0;
|
|
|
|
d_sample_counter += static_cast<uint64_t>(ninput_items[0]); // sample counter
|
|
consume_each(ninput_items[0]);
|
|
acquisition_message = 2;
|
|
this->message_port_pub(pmt::mp("events"), pmt::from_long(acquisition_message));
|
|
break;
|
|
}
|
|
}
|
|
|
|
return return_value;
|
|
}
|