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gnss-sdr/src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.cc

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/*!
* \file dll_pll_veml_tracking.cc
* \brief Implementation of a code DLL + carrier PLL tracking block.
* \author Javier Arribas, 2018. jarribas(at)cttc.es
* \author Antonio Ramos, 2018 antonio.ramosdet(at)gmail.com
*
* Code DLL + carrier PLL according to the algorithms described in:
* [1] K.Borre, D.M.Akos, N.Bertelsen, P.Rinder, and S.H.Jensen,
* A Software-Defined GPS and Galileo Receiver. A Single-Frequency
* Approach, Birkhauser, 2007
*
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2018 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
*
* This file is part of GNSS-SDR.
*
* GNSS-SDR is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GNSS-SDR is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNSS-SDR. If not, see <https://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#include "dll_pll_veml_tracking.h"
#include "Beidou_B1I.h"
#include "GPS_L1_CA.h"
#include "GPS_L2C.h"
#include "GPS_L5.h"
#include "Galileo_E1.h"
#include "Galileo_E5a.h"
#include "MATH_CONSTANTS.h"
#include "beidou_b1i_signal_processing.h"
#include "galileo_e1_signal_processing.h"
#include "galileo_e5_signal_processing.h"
#include "gnss_sdr_create_directory.h"
#include "gps_l2c_signal.h"
#include "gps_l5_signal.h"
#include "gps_sdr_signal_processing.h"
#include "lock_detectors.h"
#include "tracking_discriminators.h"
#include <boost/filesystem/path.hpp>
#include <glog/logging.h>
#include <gnuradio/io_signature.h>
#include <matio.h>
#include <volk_gnsssdr/volk_gnsssdr.h>
#include <algorithm>
#include <cmath>
#include <exception>
#include <iostream>
#include <numeric>
#include <sstream>
using google::LogMessage;
dll_pll_veml_tracking_sptr dll_pll_veml_make_tracking(const Dll_Pll_Conf &conf_)
{
return dll_pll_veml_tracking_sptr(new dll_pll_veml_tracking(conf_));
}
void dll_pll_veml_tracking::forecast(int noutput_items,
gr_vector_int &ninput_items_required)
{
if (noutput_items != 0)
{
ninput_items_required[0] = static_cast<int32_t>(trk_parameters.vector_length) * 2;
}
}
dll_pll_veml_tracking::dll_pll_veml_tracking(const Dll_Pll_Conf &conf_) : gr::block("dll_pll_veml_tracking", gr::io_signature::make(1, 1, sizeof(gr_complex)),
gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)))
{
trk_parameters = conf_;
// Telemetry bit synchronization message port input
this->message_port_register_out(pmt::mp("events"));
this->set_relative_rate(1.0 / static_cast<double>(trk_parameters.vector_length));
// Telemetry bit synchronization message port input (mainly for GPS L1 CA)
this->message_port_register_in(pmt::mp("preamble_samplestamp"));
// initialize internal vars
d_veml = false;
d_cloop = true;
d_code_chip_rate = 0.0;
d_secondary_code_length = 0U;
d_secondary_code_string = nullptr;
d_preambles_symbols = nullptr;
d_preamble_length_symbols = 0;
signal_type = std::string(trk_parameters.signal);
std::map<std::string, std::string> map_signal_pretty_name;
map_signal_pretty_name["1C"] = "L1 C/A";
map_signal_pretty_name["1B"] = "E1";
map_signal_pretty_name["1G"] = "L1 C/A";
map_signal_pretty_name["2S"] = "L2C";
map_signal_pretty_name["2G"] = "L2 C/A";
map_signal_pretty_name["5X"] = "E5a";
map_signal_pretty_name["L5"] = "L5";
map_signal_pretty_name["B1"] = "B1I";
signal_pretty_name = map_signal_pretty_name[signal_type];
if (trk_parameters.system == 'G')
{
systemName = "GPS";
if (signal_type == "1C")
{
d_signal_carrier_freq = GPS_L1_FREQ_HZ;
d_code_period = GPS_L1_CA_CODE_PERIOD;
d_code_chip_rate = GPS_L1_CA_CODE_RATE_HZ;
d_symbols_per_bit = GPS_CA_TELEMETRY_SYMBOLS_PER_BIT;
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_code_length_chips = static_cast<uint32_t>(GPS_L1_CA_CODE_LENGTH_CHIPS);
// GPS L1 C/A does not have pilot component nor secondary code
d_secondary = false;
trk_parameters.track_pilot = false;
interchange_iq = false;
// set the preamble
uint16_t preambles_bits[GPS_CA_PREAMBLE_LENGTH_BITS] = GPS_PREAMBLE;
// preamble bits to sampled symbols
d_preamble_length_symbols = GPS_CA_PREAMBLE_LENGTH_SYMBOLS;
d_preambles_symbols = static_cast<int32_t *>(volk_gnsssdr_malloc(GPS_CA_PREAMBLE_LENGTH_SYMBOLS * sizeof(int32_t), volk_gnsssdr_get_alignment()));
int32_t n = 0;
for (uint16_t preambles_bit : preambles_bits)
{
for (uint32_t j = 0; j < GPS_CA_TELEMETRY_SYMBOLS_PER_BIT; j++)
{
if (preambles_bit == 1)
{
d_preambles_symbols[n] = 1;
}
else
{
d_preambles_symbols[n] = -1;
}
n++;
}
}
d_symbol_history.resize(GPS_CA_PREAMBLE_LENGTH_SYMBOLS); // Change fixed buffer size
d_symbol_history.clear(); // Clear all the elements in the buffer
}
else if (signal_type == "2S")
{
d_signal_carrier_freq = GPS_L2_FREQ_HZ;
d_code_period = GPS_L2_M_PERIOD;
d_code_chip_rate = GPS_L2_M_CODE_RATE_HZ;
d_code_length_chips = static_cast<uint32_t>(GPS_L2_M_CODE_LENGTH_CHIPS);
d_symbols_per_bit = GPS_L2_SAMPLES_PER_SYMBOL;
d_correlation_length_ms = 20;
d_code_samples_per_chip = 1;
// GPS L2 does not have pilot component nor secondary code
d_secondary = false;
trk_parameters.track_pilot = false;
interchange_iq = false;
}
else if (signal_type == "L5")
{
d_signal_carrier_freq = GPS_L5_FREQ_HZ;
d_code_period = GPS_L5I_PERIOD;
d_code_chip_rate = GPS_L5I_CODE_RATE_HZ;
d_symbols_per_bit = GPS_L5_SAMPLES_PER_SYMBOL;
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_code_length_chips = static_cast<uint32_t>(GPS_L5I_CODE_LENGTH_CHIPS);
d_secondary = true;
if (trk_parameters.track_pilot)
{
d_secondary_code_length = static_cast<uint32_t>(GPS_L5Q_NH_CODE_LENGTH);
d_secondary_code_string = const_cast<std::string *>(&GPS_L5Q_NH_CODE_STR);
signal_pretty_name = signal_pretty_name + "Q";
interchange_iq = true;
}
else
{
d_secondary_code_length = static_cast<uint32_t>(GPS_L5I_NH_CODE_LENGTH);
d_secondary_code_string = const_cast<std::string *>(&GPS_L5I_NH_CODE_STR);
signal_pretty_name = signal_pretty_name + "I";
interchange_iq = false;
}
}
else
{
LOG(WARNING) << "Invalid Signal argument when instantiating tracking blocks";
std::cerr << "Invalid Signal argument when instantiating tracking blocks" << std::endl;
d_correlation_length_ms = 1;
d_secondary = false;
interchange_iq = false;
d_signal_carrier_freq = 0.0;
d_code_period = 0.0;
d_code_length_chips = 0U;
d_code_samples_per_chip = 0U;
d_symbols_per_bit = 0;
}
}
else if (trk_parameters.system == 'E')
{
systemName = "Galileo";
if (signal_type == "1B")
{
d_signal_carrier_freq = GALILEO_E1_FREQ_HZ;
d_code_period = GALILEO_E1_CODE_PERIOD;
d_code_chip_rate = GALILEO_E1_CODE_CHIP_RATE_HZ;
d_code_length_chips = static_cast<uint32_t>(GALILEO_E1_B_CODE_LENGTH_CHIPS);
d_symbols_per_bit = 1;
d_correlation_length_ms = 4;
d_code_samples_per_chip = 2; // CBOC disabled: 2 samples per chip. CBOC enabled: 12 samples per chip
d_veml = true;
if (trk_parameters.track_pilot)
{
d_secondary = true;
d_secondary_code_length = static_cast<uint32_t>(GALILEO_E1_C_SECONDARY_CODE_LENGTH);
d_secondary_code_string = const_cast<std::string *>(&GALILEO_E1_C_SECONDARY_CODE);
signal_pretty_name = signal_pretty_name + "C";
}
else
{
d_secondary = false;
signal_pretty_name = signal_pretty_name + "B";
}
interchange_iq = false; // Note that E1-B and E1-C are in anti-phase, NOT IN QUADRATURE. See Galileo ICD.
}
else if (signal_type == "5X")
{
d_signal_carrier_freq = GALILEO_E5A_FREQ_HZ;
d_code_period = GALILEO_E5A_CODE_PERIOD;
d_code_chip_rate = GALILEO_E5A_CODE_CHIP_RATE_HZ;
d_symbols_per_bit = 20;
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_code_length_chips = static_cast<uint32_t>(GALILEO_E5A_CODE_LENGTH_CHIPS);
if (trk_parameters.track_pilot)
{
d_secondary = true;
d_secondary_code_length = static_cast<uint32_t>(GALILEO_E5A_Q_SECONDARY_CODE_LENGTH);
signal_pretty_name = signal_pretty_name + "Q";
interchange_iq = true;
}
else
{
//Do not acquire secondary code in data component. It is done in telemetry decoder
d_secondary = false;
signal_pretty_name = signal_pretty_name + "I";
interchange_iq = false;
}
}
else
{
LOG(WARNING) << "Invalid Signal argument when instantiating tracking blocks";
std::cout << "Invalid Signal argument when instantiating tracking blocks" << std::endl;
d_correlation_length_ms = 1;
d_secondary = false;
interchange_iq = false;
d_signal_carrier_freq = 0.0;
d_code_period = 0.0;
d_code_length_chips = 0U;
d_code_samples_per_chip = 0U;
d_symbols_per_bit = 0;
}
}
else if (trk_parameters.system == 'C')
{
systemName = "Beidou";
if (signal_type == "B1")
{
// GEO Satellites use different secondary code
d_signal_carrier_freq = BEIDOU_B1I_FREQ_HZ;
d_code_period = BEIDOU_B1I_CODE_PERIOD;
d_code_chip_rate = BEIDOU_B1I_CODE_RATE_HZ;
d_code_length_chips = static_cast<unsigned int>(BEIDOU_B1I_CODE_LENGTH_CHIPS);
d_symbols_per_bit = BEIDOU_B1I_TELEMETRY_SYMBOLS_PER_BIT;
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_secondary = true;
trk_parameters.track_pilot = false;
interchange_iq = false;
d_secondary_code_length = static_cast<unsigned int>(BEIDOU_B1I_SECONDARY_CODE_LENGTH);
d_secondary_code_string = const_cast<std::string *>(&BEIDOU_B1I_SECONDARY_CODE_STR);
}
else
{
LOG(WARNING) << "Invalid Signal argument when instantiating tracking blocks";
std::cout << "Invalid Signal argument when instantiating tracking blocks" << std::endl;
d_correlation_length_ms = 1;
d_secondary = false;
interchange_iq = false;
d_signal_carrier_freq = 0.0;
d_code_period = 0.0;
d_code_length_chips = 0;
d_code_samples_per_chip = 0;
d_symbols_per_bit = 0;
}
}
else
{
LOG(WARNING) << "Invalid System argument when instantiating tracking blocks";
std::cerr << "Invalid System argument when instantiating tracking blocks" << std::endl;
d_correlation_length_ms = 1;
d_secondary = false;
interchange_iq = false;
d_signal_carrier_freq = 0.0;
d_code_period = 0.0;
d_code_length_chips = 0U;
d_code_samples_per_chip = 0U;
d_symbols_per_bit = 0;
}
T_chip_seconds = 0.0;
T_prn_seconds = 0.0;
T_prn_samples = 0.0;
K_blk_samples = 0.0;
// Initialize tracking ==========================================
d_code_loop_filter = Tracking_2nd_DLL_filter(static_cast<float>(d_code_period));
d_carrier_loop_filter = Tracking_2nd_PLL_filter(static_cast<float>(d_code_period));
d_code_loop_filter.set_DLL_BW(trk_parameters.dll_bw_hz);
d_carrier_loop_filter.set_PLL_BW(trk_parameters.pll_bw_hz);
// Initialization of local code replica
// Get space for a vector with the sinboc(1,1) replica sampled 2x/chip
d_tracking_code = static_cast<float *>(volk_gnsssdr_malloc(2 * d_code_length_chips * sizeof(float), volk_gnsssdr_get_alignment()));
// correlator outputs (scalar)
if (d_veml)
{
// Very-Early, Early, Prompt, Late, Very-Late
d_n_correlator_taps = 5;
}
else
{
// Early, Prompt, Late
d_n_correlator_taps = 3;
}
d_correlator_outs = static_cast<gr_complex *>(volk_gnsssdr_malloc(d_n_correlator_taps * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
d_local_code_shift_chips = static_cast<float *>(volk_gnsssdr_malloc(d_n_correlator_taps * sizeof(float), volk_gnsssdr_get_alignment()));
// map memory pointers of correlator outputs
if (d_veml)
{
d_Very_Early = &d_correlator_outs[0];
d_Early = &d_correlator_outs[1];
d_Prompt = &d_correlator_outs[2];
d_Late = &d_correlator_outs[3];
d_Very_Late = &d_correlator_outs[4];
d_local_code_shift_chips[0] = -trk_parameters.very_early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[1] = -trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[2] = 0.0;
d_local_code_shift_chips[3] = trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[4] = trk_parameters.very_early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_prompt_data_shift = &d_local_code_shift_chips[2];
}
else
{
d_Very_Early = nullptr;
d_Early = &d_correlator_outs[0];
d_Prompt = &d_correlator_outs[1];
d_Late = &d_correlator_outs[2];
d_Very_Late = nullptr;
d_local_code_shift_chips[0] = -trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[1] = 0.0;
d_local_code_shift_chips[2] = trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_prompt_data_shift = &d_local_code_shift_chips[1];
}
multicorrelator_cpu.init(2 * trk_parameters.vector_length, d_n_correlator_taps);
if (trk_parameters.extend_correlation_symbols > 1)
{
d_enable_extended_integration = true;
}
else
{
d_enable_extended_integration = false;
trk_parameters.extend_correlation_symbols = 1;
}
// Enable Data component prompt correlator (slave to Pilot prompt) if tracking uses Pilot signal
if (trk_parameters.track_pilot)
{
// Extra correlator for the data component
correlator_data_cpu.init(2 * trk_parameters.vector_length, 1);
correlator_data_cpu.set_high_dynamics_resampler(trk_parameters.high_dyn);
d_data_code = static_cast<float *>(volk_gnsssdr_malloc(2 * d_code_length_chips * sizeof(float), volk_gnsssdr_get_alignment()));
}
else
{
d_data_code = nullptr;
}
// --- Initializations ---
multicorrelator_cpu.set_high_dynamics_resampler(trk_parameters.high_dyn);
// Initial code frequency basis of NCO
d_code_freq_chips = d_code_chip_rate;
// Residual code phase (in chips)
d_rem_code_phase_samples = 0.0;
// Residual carrier phase
d_rem_carr_phase_rad = 0.0;
// sample synchronization
d_sample_counter = 0ULL;
d_acq_sample_stamp = 0ULL;
d_current_prn_length_samples = static_cast<int32_t>(trk_parameters.vector_length);
// CN0 estimation and lock detector buffers
d_cn0_estimation_counter = 0;
d_Prompt_buffer = new gr_complex[trk_parameters.cn0_samples];
d_carrier_lock_test = 1.0;
d_CN0_SNV_dB_Hz = 0.0;
d_carrier_lock_fail_counter = 0;
d_carrier_lock_threshold = trk_parameters.carrier_lock_th;
d_Prompt_Data = static_cast<gr_complex *>(volk_gnsssdr_malloc(sizeof(gr_complex), volk_gnsssdr_get_alignment()));
d_acquisition_gnss_synchro = nullptr;
d_channel = 0;
d_acq_code_phase_samples = 0.0;
d_acq_carrier_doppler_hz = 0.0;
d_carrier_doppler_hz = 0.0;
d_acc_carrier_phase_rad = 0.0;
d_extend_correlation_symbols_count = 0;
d_code_phase_step_chips = 0.0;
d_code_phase_rate_step_chips = 0.0;
d_carrier_phase_step_rad = 0.0;
d_carrier_phase_rate_step_rad = 0.0;
d_rem_code_phase_chips = 0.0;
d_last_prompt = gr_complex(0.0, 0.0);
d_state = 0; // initial state: standby
clear_tracking_vars();
if (trk_parameters.smoother_length > 0)
{
d_carr_ph_history.resize(trk_parameters.smoother_length * 2);
d_code_ph_history.resize(trk_parameters.smoother_length * 2);
}
else
{
d_carr_ph_history.resize(1);
d_code_ph_history.resize(1);
}
d_dump = trk_parameters.dump;
d_dump_mat = trk_parameters.dump_mat and d_dump;
if (d_dump)
{
d_dump_filename = trk_parameters.dump_filename;
std::string dump_path;
// Get path
if (d_dump_filename.find_last_of('/') != std::string::npos)
{
std::string dump_filename_ = d_dump_filename.substr(d_dump_filename.find_last_of('/') + 1);
dump_path = d_dump_filename.substr(0, d_dump_filename.find_last_of('/'));
d_dump_filename = dump_filename_;
}
else
{
dump_path = std::string(".");
}
if (d_dump_filename.empty())
{
d_dump_filename = "trk_channel_";
}
// remove extension if any
if (d_dump_filename.substr(1).find_last_of('.') != std::string::npos)
{
d_dump_filename = d_dump_filename.substr(0, d_dump_filename.find_last_of('.'));
}
d_dump_filename = dump_path + boost::filesystem::path::preferred_separator + d_dump_filename;
// create directory
if (!gnss_sdr_create_directory(dump_path))
{
std::cerr << "GNSS-SDR cannot create dump files for the tracking block. Wrong permissions?" << std::endl;
d_dump = false;
}
}
}
void dll_pll_veml_tracking::start_tracking()
{
gr::thread::scoped_lock l(d_setlock);
// correct the code phase according to the delay between acq and trk
d_acq_code_phase_samples = d_acquisition_gnss_synchro->Acq_delay_samples;
d_acq_carrier_doppler_hz = d_acquisition_gnss_synchro->Acq_doppler_hz;
d_acq_sample_stamp = d_acquisition_gnss_synchro->Acq_samplestamp_samples;
d_carrier_doppler_hz = d_acq_carrier_doppler_hz;
d_carrier_phase_step_rad = PI_2 * d_carrier_doppler_hz / trk_parameters.fs_in;
d_carrier_phase_rate_step_rad = 0.0;
d_carr_ph_history.clear();
d_code_ph_history.clear();
// DLL/PLL filter initialization
d_carrier_loop_filter.initialize(); // initialize the carrier filter
d_code_loop_filter.initialize(); // initialize the code filter
if (systemName == "GPS" and signal_type == "1C")
{
gps_l1_ca_code_gen_float(d_tracking_code, d_acquisition_gnss_synchro->PRN, 0);
}
else if (systemName == "GPS" and signal_type == "2S")
{
gps_l2c_m_code_gen_float(d_tracking_code, d_acquisition_gnss_synchro->PRN);
}
else if (systemName == "GPS" and signal_type == "L5")
{
if (trk_parameters.track_pilot)
{
gps_l5q_code_gen_float(d_tracking_code, d_acquisition_gnss_synchro->PRN);
gps_l5i_code_gen_float(d_data_code, d_acquisition_gnss_synchro->PRN);
d_Prompt_Data[0] = gr_complex(0.0, 0.0);
correlator_data_cpu.set_local_code_and_taps(d_code_length_chips, d_data_code, d_prompt_data_shift);
}
else
{
gps_l5i_code_gen_float(d_tracking_code, d_acquisition_gnss_synchro->PRN);
}
}
else if (systemName == "Galileo" and signal_type == "1B")
{
if (trk_parameters.track_pilot)
{
char pilot_signal[3] = "1C";
galileo_e1_code_gen_sinboc11_float(d_tracking_code, pilot_signal, d_acquisition_gnss_synchro->PRN);
galileo_e1_code_gen_sinboc11_float(d_data_code, d_acquisition_gnss_synchro->Signal, d_acquisition_gnss_synchro->PRN);
d_Prompt_Data[0] = gr_complex(0.0, 0.0);
correlator_data_cpu.set_local_code_and_taps(d_code_samples_per_chip * d_code_length_chips, d_data_code, d_prompt_data_shift);
}
else
{
galileo_e1_code_gen_sinboc11_float(d_tracking_code, d_acquisition_gnss_synchro->Signal, d_acquisition_gnss_synchro->PRN);
}
}
else if (systemName == "Galileo" and signal_type == "5X")
{
auto *aux_code = static_cast<gr_complex *>(volk_gnsssdr_malloc(sizeof(gr_complex) * d_code_length_chips, volk_gnsssdr_get_alignment()));
galileo_e5_a_code_gen_complex_primary(aux_code, d_acquisition_gnss_synchro->PRN, const_cast<char *>(signal_type.c_str()));
if (trk_parameters.track_pilot)
{
d_secondary_code_string = const_cast<std::string *>(&GALILEO_E5A_Q_SECONDARY_CODE[d_acquisition_gnss_synchro->PRN - 1]);
for (uint32_t i = 0; i < d_code_length_chips; i++)
{
d_tracking_code[i] = aux_code[i].imag();
d_data_code[i] = aux_code[i].real(); //the same because it is generated the full signal (E5aI + E5aQ)
}
d_Prompt_Data[0] = gr_complex(0.0, 0.0);
correlator_data_cpu.set_local_code_and_taps(d_code_length_chips, d_data_code, d_prompt_data_shift);
}
else
{
for (uint32_t i = 0; i < d_code_length_chips; i++)
{
d_tracking_code[i] = aux_code[i].real();
}
}
volk_gnsssdr_free(aux_code);
}
else if (systemName == "Beidou" and signal_type == "B1")
{
beidou_b1i_code_gen_float(d_tracking_code, d_acquisition_gnss_synchro->PRN, 0);
// Update secondary code settings for geo satellites
if (d_acquisition_gnss_synchro->PRN > 0 and d_acquisition_gnss_synchro->PRN < 6)
{
d_symbols_per_bit = 2;
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_secondary = false;
trk_parameters.track_pilot = false;
interchange_iq = false;
d_secondary_code_length = 0;
d_secondary_code_string = const_cast<std::string *>(&BEIDOU_B1I_D2_SECONDARY_CODE_STR);
// preamble bits to sampled symbols
d_preamble_length_symbols = 22;
d_preambles_symbols = static_cast<int32_t *>(volk_gnsssdr_malloc(22 * sizeof(int32_t), volk_gnsssdr_get_alignment()));
int32_t n = 0;
uint16_t preambles_bits[BEIDOU_B1I_PREAMBLE_LENGTH_BITS] = {1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0};
for (uint16_t preambles_bit : preambles_bits)
{
for (int32_t j = 0; j < d_symbols_per_bit; j++)
{
if (preambles_bit == 1)
{
d_preambles_symbols[n] = 1;
}
else
{
d_preambles_symbols[n] = -1;
}
n++;
}
}
d_symbol_history.resize(22); // Change fixed buffer size
d_symbol_history.clear();
}
}
multicorrelator_cpu.set_local_code_and_taps(d_code_samples_per_chip * d_code_length_chips, d_tracking_code, d_local_code_shift_chips);
std::fill_n(d_correlator_outs, d_n_correlator_taps, gr_complex(0.0, 0.0));
d_carrier_lock_fail_counter = 0;
d_rem_code_phase_samples = 0.0;
d_rem_carr_phase_rad = 0.0;
d_rem_code_phase_chips = 0.0;
d_acc_carrier_phase_rad = 0.0;
d_cn0_estimation_counter = 0;
d_carrier_lock_test = 1.0;
d_CN0_SNV_dB_Hz = 0.0;
if (d_veml)
{
d_local_code_shift_chips[0] = -trk_parameters.very_early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[1] = -trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[3] = trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[4] = trk_parameters.very_early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
}
else
{
d_local_code_shift_chips[0] = -trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[2] = trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
}
d_code_loop_filter.set_DLL_BW(trk_parameters.dll_bw_hz);
d_carrier_loop_filter.set_PLL_BW(trk_parameters.pll_bw_hz);
d_carrier_loop_filter.set_pdi(static_cast<float>(d_code_period));
d_code_loop_filter.set_pdi(static_cast<float>(d_code_period));
// DEBUG OUTPUT
std::cout << "Tracking of " << systemName << " " << signal_pretty_name << " signal started on channel " << d_channel << " for satellite " << Gnss_Satellite(systemName, d_acquisition_gnss_synchro->PRN) << std::endl;
DLOG(INFO) << "Starting tracking of satellite " << Gnss_Satellite(systemName, d_acquisition_gnss_synchro->PRN) << " on channel " << d_channel;
// enable tracking pull-in
d_state = 1;
d_cloop = true;
d_Prompt_buffer_deque.clear();
d_last_prompt = gr_complex(0.0, 0.0);
}
dll_pll_veml_tracking::~dll_pll_veml_tracking()
{
if (signal_type == "1C")
{
volk_gnsssdr_free(d_preambles_symbols);
}
if (d_dump_file.is_open())
{
try
{
d_dump_file.close();
}
catch (const std::exception &ex)
{
LOG(WARNING) << "Exception in destructor " << ex.what();
}
}
if (d_dump_mat)
{
try
{
save_matfile();
}
catch (const std::exception &ex)
{
LOG(WARNING) << "Error saving the .mat file: " << ex.what();
}
}
try
{
volk_gnsssdr_free(d_local_code_shift_chips);
volk_gnsssdr_free(d_correlator_outs);
volk_gnsssdr_free(d_tracking_code);
volk_gnsssdr_free(d_Prompt_Data);
if (trk_parameters.track_pilot)
{
volk_gnsssdr_free(d_data_code);
correlator_data_cpu.free();
}
delete[] d_Prompt_buffer;
multicorrelator_cpu.free();
}
catch (const std::exception &ex)
{
LOG(WARNING) << "Exception in destructor " << ex.what();
}
}
bool dll_pll_veml_tracking::acquire_secondary()
{
// ******* preamble correlation ********
int32_t corr_value = 0;
for (uint32_t i = 0; i < d_secondary_code_length; i++)
{
if (d_Prompt_buffer_deque.at(i).real() < 0.0) // symbols clipping
{
if (d_secondary_code_string->at(i) == '0')
{
corr_value++;
}
else
{
corr_value--;
}
}
else
{
if (d_secondary_code_string->at(i) == '0')
{
corr_value--;
}
else
{
corr_value++;
}
}
}
if (abs(corr_value) == static_cast<int32_t>(d_secondary_code_length))
{
return true;
}
return false;
}
bool dll_pll_veml_tracking::cn0_and_tracking_lock_status(double coh_integration_time_s)
{
// ####### CN0 ESTIMATION AND LOCK DETECTORS ######
if (d_cn0_estimation_counter < trk_parameters.cn0_samples)
{
// fill buffer with prompt correlator output values
d_Prompt_buffer[d_cn0_estimation_counter] = d_P_accu;
d_cn0_estimation_counter++;
return true;
}
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, trk_parameters.cn0_samples, coh_integration_time_s);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, trk_parameters.cn0_samples);
// Loss of lock detection
if (d_carrier_lock_test < d_carrier_lock_threshold or d_CN0_SNV_dB_Hz < trk_parameters.cn0_min)
{
d_carrier_lock_fail_counter++;
}
else
{
if (d_carrier_lock_fail_counter > 0)
{
d_carrier_lock_fail_counter--;
}
}
if (d_carrier_lock_fail_counter > trk_parameters.max_lock_fail)
{
std::cout << "Loss of lock in channel " << d_channel << "!" << std::endl;
LOG(INFO) << "Loss of lock in channel " << d_channel << "!";
this->message_port_pub(pmt::mp("events"), pmt::from_long(3)); // 3 -> loss of lock
d_carrier_lock_fail_counter = 0;
return false;
}
return true;
}
// correlation requires:
// - updated remnant carrier phase in radians (rem_carr_phase_rad)
// - updated remnant code phase in samples (d_rem_code_phase_samples)
// - d_code_freq_chips
// - d_carrier_doppler_hz
void dll_pll_veml_tracking::do_correlation_step(const gr_complex *input_samples)
{
// ################# CARRIER WIPEOFF AND CORRELATORS ##############################
// perform carrier wipe-off and compute Early, Prompt and Late correlation
multicorrelator_cpu.set_input_output_vectors(d_correlator_outs, input_samples);
multicorrelator_cpu.Carrier_wipeoff_multicorrelator_resampler(
d_rem_carr_phase_rad,
d_carrier_phase_step_rad, d_carrier_phase_rate_step_rad,
static_cast<float>(d_rem_code_phase_chips) * static_cast<float>(d_code_samples_per_chip),
static_cast<float>(d_code_phase_step_chips) * static_cast<float>(d_code_samples_per_chip),
static_cast<float>(d_code_phase_rate_step_chips) * static_cast<float>(d_code_samples_per_chip),
trk_parameters.vector_length);
// DATA CORRELATOR (if tracking tracks the pilot signal)
if (trk_parameters.track_pilot)
{
correlator_data_cpu.set_input_output_vectors(d_Prompt_Data, input_samples);
correlator_data_cpu.Carrier_wipeoff_multicorrelator_resampler(
d_rem_carr_phase_rad,
d_carrier_phase_step_rad, d_carrier_phase_rate_step_rad,
static_cast<float>(d_rem_code_phase_chips) * static_cast<float>(d_code_samples_per_chip),
static_cast<float>(d_code_phase_step_chips) * static_cast<float>(d_code_samples_per_chip),
static_cast<float>(d_code_phase_rate_step_chips) * static_cast<float>(d_code_samples_per_chip),
trk_parameters.vector_length);
}
}
void dll_pll_veml_tracking::run_dll_pll()
{
// ################## PLL ##########################################################
// PLL discriminator
if (d_cloop)
{
// Costas loop discriminator, insensitive to 180 deg phase transitions
d_carr_error_hz = pll_cloop_two_quadrant_atan(d_P_accu) / PI_2;
}
else
{
// Secondary code acquired. No symbols transition should be present in the signal
d_carr_error_hz = pll_four_quadrant_atan(d_P_accu) / PI_2;
}
// Carrier discriminator filter
d_carr_error_filt_hz = d_carrier_loop_filter.get_carrier_nco(d_carr_error_hz);
// New carrier Doppler frequency estimation
d_carrier_doppler_hz = d_acq_carrier_doppler_hz + d_carr_error_filt_hz;
// ################## DLL ##########################################################
// DLL discriminator
if (d_veml)
{
d_code_error_chips = dll_nc_vemlp_normalized(d_VE_accu, d_E_accu, d_L_accu, d_VL_accu); // [chips/Ti]
}
else
{
d_code_error_chips = dll_nc_e_minus_l_normalized(d_E_accu, d_L_accu); // [chips/Ti]
}
// Code discriminator filter
d_code_error_filt_chips = d_code_loop_filter.get_code_nco(d_code_error_chips); // [chips/second]
// New code Doppler frequency estimation
d_code_freq_chips = (1.0 + (d_carrier_doppler_hz / d_signal_carrier_freq)) * d_code_chip_rate - d_code_error_filt_chips;
}
void dll_pll_veml_tracking::clear_tracking_vars()
{
std::fill_n(d_correlator_outs, d_n_correlator_taps, gr_complex(0.0, 0.0));
if (trk_parameters.track_pilot)
{
d_Prompt_Data[0] = gr_complex(0.0, 0.0);
}
d_carr_error_hz = 0.0;
d_carr_error_filt_hz = 0.0;
d_code_error_chips = 0.0;
d_code_error_filt_chips = 0.0;
d_current_symbol = 0;
d_Prompt_buffer_deque.clear();
d_last_prompt = gr_complex(0.0, 0.0);
d_carrier_phase_rate_step_rad = 0.0;
d_code_phase_rate_step_chips = 0.0;
d_carr_ph_history.clear();
d_code_ph_history.clear();
}
void dll_pll_veml_tracking::update_tracking_vars()
{
T_chip_seconds = 1.0 / d_code_freq_chips;
T_prn_seconds = T_chip_seconds * static_cast<double>(d_code_length_chips);
// ################## CARRIER AND CODE NCO BUFFER ALIGNMENT #######################
// keep alignment parameters for the next input buffer
// Compute the next buffer length based in the new period of the PRN sequence and the code phase error estimation
T_prn_samples = T_prn_seconds * trk_parameters.fs_in;
K_blk_samples = T_prn_samples + d_rem_code_phase_samples;
//d_current_prn_length_samples = static_cast<int32_t>(round(K_blk_samples)); // round to a discrete number of samples
d_current_prn_length_samples = static_cast<int32_t>(std::floor(K_blk_samples)); // round to a discrete number of samples
//################### PLL COMMANDS #################################################
// carrier phase step (NCO phase increment per sample) [rads/sample]
d_carrier_phase_step_rad = PI_2 * d_carrier_doppler_hz / trk_parameters.fs_in;
// carrier phase rate step (NCO phase increment rate per sample) [rads/sample^2]
if (trk_parameters.high_dyn)
{
d_carr_ph_history.push_back(std::pair<double, double>(d_carrier_phase_step_rad, static_cast<double>(d_current_prn_length_samples)));
if (d_carr_ph_history.full())
{
double tmp_cp1 = 0.0;
double tmp_cp2 = 0.0;
double tmp_samples = 0.0;
for (unsigned int k = 0; k < trk_parameters.smoother_length; k++)
{
tmp_cp1 += d_carr_ph_history.at(k).first;
tmp_cp2 += d_carr_ph_history.at(trk_parameters.smoother_length * 2 - k - 1).first;
tmp_samples += d_carr_ph_history.at(trk_parameters.smoother_length * 2 - k - 1).second;
}
tmp_cp1 /= static_cast<double>(trk_parameters.smoother_length);
tmp_cp2 /= static_cast<double>(trk_parameters.smoother_length);
d_carrier_phase_rate_step_rad = (tmp_cp2 - tmp_cp1) / tmp_samples;
}
}
//std::cout << d_carrier_phase_rate_step_rad * trk_parameters.fs_in * trk_parameters.fs_in / PI_2 << std::endl;
// remnant carrier phase to prevent overflow in the code NCO
d_rem_carr_phase_rad += static_cast<float>(d_carrier_phase_step_rad * static_cast<double>(d_current_prn_length_samples) + 0.5 * d_carrier_phase_rate_step_rad * static_cast<double>(d_current_prn_length_samples) * static_cast<double>(d_current_prn_length_samples));
d_rem_carr_phase_rad = fmod(d_rem_carr_phase_rad, PI_2);
// carrier phase accumulator
//double a = d_carrier_phase_step_rad * static_cast<double>(d_current_prn_length_samples);
//double b = 0.5 * d_carrier_phase_rate_step_rad * static_cast<double>(d_current_prn_length_samples) * static_cast<double>(d_current_prn_length_samples);
//std::cout << fmod(b, PI_2) / fmod(a, PI_2) << std::endl;
d_acc_carrier_phase_rad -= (d_carrier_phase_step_rad * static_cast<double>(d_current_prn_length_samples) + 0.5 * d_carrier_phase_rate_step_rad * static_cast<double>(d_current_prn_length_samples) * static_cast<double>(d_current_prn_length_samples));
//################### DLL COMMANDS #################################################
// code phase step (Code resampler phase increment per sample) [chips/sample]
d_code_phase_step_chips = d_code_freq_chips / trk_parameters.fs_in;
if (trk_parameters.high_dyn)
{
d_code_ph_history.push_back(std::pair<double, double>(d_code_phase_step_chips, static_cast<double>(d_current_prn_length_samples)));
if (d_code_ph_history.full())
{
double tmp_cp1 = 0.0;
double tmp_cp2 = 0.0;
double tmp_samples = 0.0;
for (unsigned int k = 0; k < trk_parameters.smoother_length; k++)
{
tmp_cp1 += d_code_ph_history.at(k).first;
tmp_cp2 += d_code_ph_history.at(trk_parameters.smoother_length * 2 - k - 1).first;
tmp_samples += d_code_ph_history.at(trk_parameters.smoother_length * 2 - k - 1).second;
}
tmp_cp1 /= static_cast<double>(trk_parameters.smoother_length);
tmp_cp2 /= static_cast<double>(trk_parameters.smoother_length);
d_code_phase_rate_step_chips = (tmp_cp2 - tmp_cp1) / tmp_samples;
}
}
// remnant code phase [chips]
d_rem_code_phase_samples = K_blk_samples - static_cast<double>(d_current_prn_length_samples); // rounding error < 1 sample
d_rem_code_phase_chips = d_code_freq_chips * d_rem_code_phase_samples / trk_parameters.fs_in;
}
void dll_pll_veml_tracking::save_correlation_results()
{
if (d_secondary)
{
if (d_secondary_code_string->at(d_current_symbol) == '0')
{
if (d_veml)
{
d_VE_accu += *d_Very_Early;
d_VL_accu += *d_Very_Late;
}
d_E_accu += *d_Early;
d_P_accu += *d_Prompt;
d_L_accu += *d_Late;
}
else
{
if (d_veml)
{
d_VE_accu -= *d_Very_Early;
d_VL_accu -= *d_Very_Late;
}
d_E_accu -= *d_Early;
d_P_accu -= *d_Prompt;
d_L_accu -= *d_Late;
}
d_current_symbol++;
// secondary code roll-up
d_current_symbol %= d_secondary_code_length;
}
else
{
if (d_veml)
{
d_VE_accu += *d_Very_Early;
d_VL_accu += *d_Very_Late;
}
d_E_accu += *d_Early;
d_P_accu += *d_Prompt;
d_L_accu += *d_Late;
d_current_symbol++;
d_current_symbol %= d_symbols_per_bit;
}
// If tracking pilot, disable Costas loop
if (trk_parameters.track_pilot)
{
d_cloop = false;
}
else
{
d_cloop = true;
}
}
void dll_pll_veml_tracking::log_data(bool integrating)
{
if (d_dump)
{
// Dump results to file
float prompt_I;
float prompt_Q;
float tmp_VE, tmp_E, tmp_P, tmp_L, tmp_VL;
float tmp_float;
double tmp_double;
uint64_t tmp_long_int;
if (trk_parameters.track_pilot)
{
if (interchange_iq)
{
prompt_I = d_Prompt_Data->imag();
prompt_Q = d_Prompt_Data->real();
}
else
{
prompt_I = d_Prompt_Data->real();
prompt_Q = d_Prompt_Data->imag();
}
}
else
{
if (interchange_iq)
{
prompt_I = d_Prompt->imag();
prompt_Q = d_Prompt->real();
}
else
{
prompt_I = d_Prompt->real();
prompt_Q = d_Prompt->imag();
}
}
if (d_veml)
{
tmp_VE = std::abs<float>(d_VE_accu);
tmp_VL = std::abs<float>(d_VL_accu);
}
else
{
tmp_VE = 0.0;
tmp_VL = 0.0;
}
tmp_E = std::abs<float>(d_E_accu);
tmp_P = std::abs<float>(d_P_accu);
tmp_L = std::abs<float>(d_L_accu);
if (integrating)
{
//TODO: Improve this solution!
// It compensates the amplitude difference while integrating
if (d_extend_correlation_symbols_count > 0)
{
float scale_factor = static_cast<float>(trk_parameters.extend_correlation_symbols) / static_cast<float>(d_extend_correlation_symbols_count);
tmp_VE *= scale_factor;
tmp_E *= scale_factor;
tmp_P *= scale_factor;
tmp_L *= scale_factor;
tmp_VL *= scale_factor;
}
}
try
{
// Dump correlators output
d_dump_file.write(reinterpret_cast<char *>(&tmp_VE), sizeof(float));
d_dump_file.write(reinterpret_cast<char *>(&tmp_E), sizeof(float));
d_dump_file.write(reinterpret_cast<char *>(&tmp_P), sizeof(float));
d_dump_file.write(reinterpret_cast<char *>(&tmp_L), sizeof(float));
d_dump_file.write(reinterpret_cast<char *>(&tmp_VL), sizeof(float));
// PROMPT I and Q (to analyze navigation symbols)
d_dump_file.write(reinterpret_cast<char *>(&prompt_I), sizeof(float));
d_dump_file.write(reinterpret_cast<char *>(&prompt_Q), sizeof(float));
// PRN start sample stamp
tmp_long_int = d_sample_counter + static_cast<uint64_t>(d_current_prn_length_samples);
d_dump_file.write(reinterpret_cast<char *>(&tmp_long_int), sizeof(uint64_t));
// accumulated carrier phase
tmp_float = d_acc_carrier_phase_rad;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// carrier and code frequency
tmp_float = d_carrier_doppler_hz;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// carrier phase rate [Hz/s]
tmp_float = d_carrier_phase_rate_step_rad * trk_parameters.fs_in * trk_parameters.fs_in / PI_2;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
tmp_float = d_code_freq_chips;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// code phase rate [chips/s^2]
tmp_float = d_code_phase_rate_step_chips * trk_parameters.fs_in * trk_parameters.fs_in;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// PLL commands
tmp_float = d_carr_error_hz;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
tmp_float = d_carr_error_filt_hz;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// DLL commands
tmp_float = d_code_error_chips;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
tmp_float = d_code_error_filt_chips;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// CN0 and carrier lock test
tmp_float = d_CN0_SNV_dB_Hz;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
tmp_float = d_carrier_lock_test;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// AUX vars (for debug purposes)
tmp_float = d_rem_code_phase_samples;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
tmp_double = static_cast<double>(d_sample_counter + d_current_prn_length_samples);
d_dump_file.write(reinterpret_cast<char *>(&tmp_double), sizeof(double));
// PRN
uint32_t prn_ = d_acquisition_gnss_synchro->PRN;
d_dump_file.write(reinterpret_cast<char *>(&prn_), sizeof(uint32_t));
}
catch (const std::ifstream::failure &e)
{
LOG(WARNING) << "Exception writing trk dump file " << e.what();
}
}
}
int32_t dll_pll_veml_tracking::save_matfile()
{
// READ DUMP FILE
std::ifstream::pos_type size;
int32_t number_of_double_vars = 1;
int32_t number_of_float_vars = 19;
int32_t epoch_size_bytes = sizeof(uint64_t) + sizeof(double) * number_of_double_vars +
sizeof(float) * number_of_float_vars + sizeof(uint32_t);
std::ifstream dump_file;
std::string dump_filename_ = d_dump_filename;
// add channel number to the filename
dump_filename_.append(std::to_string(d_channel));
// add extension
dump_filename_.append(".dat");
std::cout << "Generating .mat file for " << dump_filename_ << std::endl;
dump_file.exceptions(std::ifstream::failbit | std::ifstream::badbit);
try
{
dump_file.open(dump_filename_.c_str(), std::ios::binary | std::ios::ate);
}
catch (const std::ifstream::failure &e)
{
std::cerr << "Problem opening dump file:" << e.what() << std::endl;
return 1;
}
// count number of epochs and rewind
int64_t num_epoch = 0;
if (dump_file.is_open())
{
size = dump_file.tellg();
num_epoch = static_cast<int64_t>(size) / static_cast<int64_t>(epoch_size_bytes);
dump_file.seekg(0, std::ios::beg);
}
else
{
return 1;
}
auto *abs_VE = new float[num_epoch];
auto *abs_E = new float[num_epoch];
auto *abs_P = new float[num_epoch];
auto *abs_L = new float[num_epoch];
auto *abs_VL = new float[num_epoch];
auto *Prompt_I = new float[num_epoch];
auto *Prompt_Q = new float[num_epoch];
auto *PRN_start_sample_count = new uint64_t[num_epoch];
auto *acc_carrier_phase_rad = new float[num_epoch];
auto *carrier_doppler_hz = new float[num_epoch];
auto *carrier_doppler_rate_hz = new float[num_epoch];
auto *code_freq_chips = new float[num_epoch];
auto *code_freq_rate_chips = new float[num_epoch];
auto *carr_error_hz = new float[num_epoch];
auto *carr_error_filt_hz = new float[num_epoch];
auto *code_error_chips = new float[num_epoch];
auto *code_error_filt_chips = new float[num_epoch];
auto *CN0_SNV_dB_Hz = new float[num_epoch];
auto *carrier_lock_test = new float[num_epoch];
auto *aux1 = new float[num_epoch];
auto *aux2 = new double[num_epoch];
auto *PRN = new uint32_t[num_epoch];
try
{
if (dump_file.is_open())
{
for (int64_t i = 0; i < num_epoch; i++)
{
dump_file.read(reinterpret_cast<char *>(&abs_VE[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&abs_E[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&abs_P[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&abs_L[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&abs_VL[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&Prompt_I[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&Prompt_Q[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&PRN_start_sample_count[i]), sizeof(uint64_t));
dump_file.read(reinterpret_cast<char *>(&acc_carrier_phase_rad[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&carrier_doppler_hz[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&carrier_doppler_rate_hz[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&code_freq_chips[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&code_freq_rate_chips[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&carr_error_hz[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&carr_error_filt_hz[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&code_error_chips[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&code_error_filt_chips[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&CN0_SNV_dB_Hz[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&carrier_lock_test[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&aux1[i]), sizeof(float));
dump_file.read(reinterpret_cast<char *>(&aux2[i]), sizeof(double));
dump_file.read(reinterpret_cast<char *>(&PRN[i]), sizeof(uint32_t));
}
}
dump_file.close();
}
catch (const std::ifstream::failure &e)
{
std::cerr << "Problem reading dump file:" << e.what() << std::endl;
delete[] abs_VE;
delete[] abs_E;
delete[] abs_P;
delete[] abs_L;
delete[] abs_VL;
delete[] Prompt_I;
delete[] Prompt_Q;
delete[] PRN_start_sample_count;
delete[] acc_carrier_phase_rad;
delete[] carrier_doppler_hz;
delete[] carrier_doppler_rate_hz;
delete[] code_freq_chips;
delete[] code_freq_rate_chips;
delete[] carr_error_hz;
delete[] carr_error_filt_hz;
delete[] code_error_chips;
delete[] code_error_filt_chips;
delete[] CN0_SNV_dB_Hz;
delete[] carrier_lock_test;
delete[] aux1;
delete[] aux2;
delete[] PRN;
return 1;
}
// WRITE MAT FILE
mat_t *matfp;
matvar_t *matvar;
std::string filename = dump_filename_;
filename.erase(filename.length() - 4, 4);
filename.append(".mat");
matfp = Mat_CreateVer(filename.c_str(), nullptr, MAT_FT_MAT73);
if (reinterpret_cast<int64_t *>(matfp) != nullptr)
{
size_t dims[2] = {1, static_cast<size_t>(num_epoch)};
matvar = Mat_VarCreate("abs_VE", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, abs_VE, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("abs_E", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, abs_E, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("abs_P", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, abs_P, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("abs_L", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, abs_L, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("abs_VL", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, abs_VL, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("Prompt_I", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, Prompt_I, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("Prompt_Q", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, Prompt_Q, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("PRN_start_sample_count", MAT_C_UINT64, MAT_T_UINT64, 2, dims, PRN_start_sample_count, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("acc_carrier_phase_rad", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, acc_carrier_phase_rad, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("carrier_doppler_hz", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, carrier_doppler_hz, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("carrier_doppler_rate_hz", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, carrier_doppler_rate_hz, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("code_freq_chips", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, code_freq_chips, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("code_freq_rate_chips", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, code_freq_rate_chips, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("carr_error_hz", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, carr_error_hz, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("carr_error_filt_hz", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, carr_error_filt_hz, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("code_error_chips", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, code_error_chips, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("code_error_filt_chips", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, code_error_filt_chips, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("CN0_SNV_dB_Hz", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, CN0_SNV_dB_Hz, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("carrier_lock_test", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, carrier_lock_test, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("aux1", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, aux1, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("aux2", MAT_C_DOUBLE, MAT_T_DOUBLE, 2, dims, aux2, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("PRN", MAT_C_UINT32, MAT_T_UINT32, 2, dims, PRN, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
}
Mat_Close(matfp);
delete[] abs_VE;
delete[] abs_E;
delete[] abs_P;
delete[] abs_L;
delete[] abs_VL;
delete[] Prompt_I;
delete[] Prompt_Q;
delete[] PRN_start_sample_count;
delete[] acc_carrier_phase_rad;
delete[] carrier_doppler_hz;
delete[] carrier_doppler_rate_hz;
delete[] code_freq_chips;
delete[] code_freq_rate_chips;
delete[] carr_error_hz;
delete[] carr_error_filt_hz;
delete[] code_error_chips;
delete[] code_error_filt_chips;
delete[] CN0_SNV_dB_Hz;
delete[] carrier_lock_test;
delete[] aux1;
delete[] aux2;
delete[] PRN;
return 0;
}
void dll_pll_veml_tracking::set_channel(uint32_t channel)
{
gr::thread::scoped_lock l(d_setlock);
d_channel = channel;
LOG(INFO) << "Tracking Channel set to " << d_channel;
// ############# ENABLE DATA FILE LOG #################
if (d_dump)
{
std::string dump_filename_ = d_dump_filename;
// add channel number to the filename
dump_filename_.append(std::to_string(d_channel));
// add extension
dump_filename_.append(".dat");
if (!d_dump_file.is_open())
{
try
{
//trk_parameters.dump_filename.append(boost::lexical_cast<std::string>(d_channel));
//trk_parameters.dump_filename.append(".dat");
d_dump_file.exceptions(std::ifstream::failbit | std::ifstream::badbit);
d_dump_file.open(dump_filename_.c_str(), std::ios::out | std::ios::binary);
LOG(INFO) << "Tracking dump enabled on channel " << d_channel << " Log file: " << dump_filename_.c_str();
}
catch (const std::ifstream::failure &e)
{
LOG(WARNING) << "channel " << d_channel << " Exception opening trk dump file " << e.what();
}
}
}
}
void dll_pll_veml_tracking::set_gnss_synchro(Gnss_Synchro *p_gnss_synchro)
{
gr::thread::scoped_lock l(d_setlock);
d_acquisition_gnss_synchro = p_gnss_synchro;
}
void dll_pll_veml_tracking::stop_tracking()
{
gr::thread::scoped_lock l(d_setlock);
d_state = 0;
}
int dll_pll_veml_tracking::general_work(int noutput_items __attribute__((unused)), gr_vector_int &ninput_items,
gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)
{
gr::thread::scoped_lock l(d_setlock);
const auto *in = reinterpret_cast<const gr_complex *>(input_items[0]);
auto **out = reinterpret_cast<Gnss_Synchro **>(&output_items[0]);
Gnss_Synchro current_synchro_data = Gnss_Synchro();
switch (d_state)
{
case 0: // Standby - Consume samples at full throttle, do nothing
{
d_sample_counter += static_cast<uint64_t>(ninput_items[0]);
consume_each(ninput_items[0]);
return 0;
break;
}
case 1: // Pull-in
{
// Signal alignment (skip samples until the incoming signal is aligned with local replica)
int64_t acq_trk_diff_samples = static_cast<int64_t>(d_sample_counter) - static_cast<int64_t>(d_acq_sample_stamp);
double acq_trk_diff_seconds = static_cast<double>(acq_trk_diff_samples) / trk_parameters.fs_in;
double delta_trk_to_acq_prn_start_samples = static_cast<double>(acq_trk_diff_samples) - d_acq_code_phase_samples;
// Doppler effect Fd = (C / (C + Vr)) * F
double radial_velocity = (d_signal_carrier_freq + d_acq_carrier_doppler_hz) / d_signal_carrier_freq;
// new chip and PRN sequence periods based on acq Doppler
d_code_freq_chips = radial_velocity * d_code_chip_rate;
d_code_freq_chips = d_code_chip_rate;
d_code_phase_step_chips = d_code_freq_chips / trk_parameters.fs_in;
d_code_phase_rate_step_chips = 0.0;
double T_chip_mod_seconds = 1.0 / d_code_freq_chips;
double T_prn_mod_seconds = T_chip_mod_seconds * static_cast<double>(d_code_length_chips);
double T_prn_mod_samples = T_prn_mod_seconds * trk_parameters.fs_in;
d_acq_code_phase_samples = T_prn_mod_samples - std::fmod(delta_trk_to_acq_prn_start_samples, T_prn_mod_samples);
d_current_prn_length_samples = round(T_prn_mod_samples);
int32_t samples_offset = round(d_acq_code_phase_samples);
d_acc_carrier_phase_rad -= d_carrier_phase_step_rad * static_cast<double>(samples_offset);
d_state = 2;
d_sample_counter += samples_offset; // count for the processed samples
DLOG(INFO) << "Number of samples between Acquisition and Tracking = " << acq_trk_diff_samples << " ( " << acq_trk_diff_seconds << " s)";
DLOG(INFO) << "PULL-IN Doppler [Hz] = " << d_carrier_doppler_hz
<< ". PULL-IN Code Phase [samples] = " << d_acq_code_phase_samples;
consume_each(samples_offset); // shift input to perform alignment with local replica
return 0;
}
case 2: // Wide tracking and symbol synchronization
{
do_correlation_step(in);
// Save single correlation step variables
if (d_veml)
{
d_VE_accu = *d_Very_Early;
d_VL_accu = *d_Very_Late;
}
d_E_accu = *d_Early;
d_P_accu = *d_Prompt;
d_L_accu = *d_Late;
// Check lock status
if (!cn0_and_tracking_lock_status(d_code_period))
{
clear_tracking_vars();
d_state = 0; // loss-of-lock detected
}
else
{
bool next_state = false;
// Perform DLL/PLL tracking loop computations. Costas Loop enabled
run_dll_pll();
update_tracking_vars();
// enable write dump file this cycle (valid DLL/PLL cycle)
log_data(false);
if (d_secondary)
{
// ####### SECONDARY CODE LOCK #####
d_Prompt_buffer_deque.push_back(*d_Prompt);
if (d_Prompt_buffer_deque.size() == d_secondary_code_length)
{
next_state = acquire_secondary();
if (next_state)
{
LOG(INFO) << systemName << " " << signal_pretty_name << " secondary code locked in channel " << d_channel
<< " for satellite " << Gnss_Satellite(systemName, d_acquisition_gnss_synchro->PRN) << std::endl;
std::cout << systemName << " " << signal_pretty_name << " secondary code locked in channel " << d_channel
<< " for satellite " << Gnss_Satellite(systemName, d_acquisition_gnss_synchro->PRN) << std::endl;
}
d_Prompt_buffer_deque.pop_front();
}
}
else if (d_symbols_per_bit > 1) //Signal does not have secondary code. Search a bit transition by sign change
{
float current_tracking_time_s = static_cast<float>(d_sample_counter - d_acq_sample_stamp) / trk_parameters.fs_in;
if (current_tracking_time_s > 10)
{
d_symbol_history.push_back(d_Prompt->real());
//******* preamble correlation ********
int32_t corr_value = 0;
if ((static_cast<int32_t>(d_symbol_history.size()) == d_preamble_length_symbols)) // and (d_make_correlation or !d_flag_frame_sync))
{
for (int32_t i = 0; i < d_preamble_length_symbols; i++)
{
if (d_symbol_history.at(i) < 0) // symbols clipping
{
corr_value -= d_preambles_symbols[i];
}
else
{
corr_value += d_preambles_symbols[i];
}
}
}
if (corr_value == d_preamble_length_symbols)
{
LOG(INFO) << systemName << " " << signal_pretty_name << " tracking preamble detected in channel " << d_channel
<< " for satellite " << Gnss_Satellite(systemName, d_acquisition_gnss_synchro->PRN) << std::endl;
next_state = true;
}
else
{
next_state = false;
}
}
else
{
next_state = false;
}
}
else
{
next_state = true;
}
// ########### Output the tracking results to Telemetry block ##########
if (interchange_iq)
{
if (trk_parameters.track_pilot)
{
// Note that data and pilot components are in quadrature. I and Q are interchanged
current_synchro_data.Prompt_I = static_cast<double>((*d_Prompt_Data).imag());
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt_Data).real());
}
else
{
current_synchro_data.Prompt_I = static_cast<double>((*d_Prompt).imag());
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt).real());
}
}
else
{
if (trk_parameters.track_pilot)
{
// Note that data and pilot components are in quadrature. I and Q are interchanged
current_synchro_data.Prompt_I = static_cast<double>((*d_Prompt_Data).real());
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt_Data).imag());
}
else
{
current_synchro_data.Prompt_I = static_cast<double>((*d_Prompt).real());
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt).imag());
}
}
current_synchro_data.Code_phase_samples = d_rem_code_phase_samples;
current_synchro_data.Carrier_phase_rads = d_acc_carrier_phase_rad;
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
current_synchro_data.Flag_valid_symbol_output = true;
current_synchro_data.correlation_length_ms = d_correlation_length_ms;
if (next_state)
{ // reset extended correlator
d_VE_accu = gr_complex(0.0, 0.0);
d_E_accu = gr_complex(0.0, 0.0);
d_P_accu = gr_complex(0.0, 0.0);
d_L_accu = gr_complex(0.0, 0.0);
d_VL_accu = gr_complex(0.0, 0.0);
d_last_prompt = gr_complex(0.0, 0.0);
d_Prompt_buffer_deque.clear();
d_current_symbol = 0;
if (d_enable_extended_integration)
{
// UPDATE INTEGRATION TIME
d_extend_correlation_symbols_count = 0;
float new_correlation_time = static_cast<float>(trk_parameters.extend_correlation_symbols) * static_cast<float>(d_code_period);
d_carrier_loop_filter.set_pdi(new_correlation_time);
d_code_loop_filter.set_pdi(new_correlation_time);
d_state = 3; // next state is the extended correlator integrator
LOG(INFO) << "Enabled " << trk_parameters.extend_correlation_symbols * static_cast<int32_t>(d_code_period * 1000.0) << " ms extended correlator in channel "
<< d_channel
<< " for satellite " << Gnss_Satellite(systemName, d_acquisition_gnss_synchro->PRN);
std::cout << "Enabled " << trk_parameters.extend_correlation_symbols * static_cast<int32_t>(d_code_period * 1000.0) << " ms extended correlator in channel "
<< d_channel
<< " for satellite " << Gnss_Satellite(systemName, d_acquisition_gnss_synchro->PRN) << std::endl;
// Set narrow taps delay values [chips]
d_code_loop_filter.set_DLL_BW(trk_parameters.dll_bw_narrow_hz);
d_carrier_loop_filter.set_PLL_BW(trk_parameters.pll_bw_narrow_hz);
if (d_veml)
{
d_local_code_shift_chips[0] = -trk_parameters.very_early_late_space_narrow_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[1] = -trk_parameters.early_late_space_narrow_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[3] = trk_parameters.early_late_space_narrow_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[4] = trk_parameters.very_early_late_space_narrow_chips * static_cast<float>(d_code_samples_per_chip);
}
else
{
d_local_code_shift_chips[0] = -trk_parameters.early_late_space_narrow_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[2] = trk_parameters.early_late_space_narrow_chips * static_cast<float>(d_code_samples_per_chip);
}
}
else
{
d_state = 4;
}
}
}
break;
}
case 3: // coherent integration (correlation time extension)
{
// Fill the acquisition data
current_synchro_data = *d_acquisition_gnss_synchro;
// perform a correlation step
do_correlation_step(in);
update_tracking_vars();
save_correlation_results();
// ########### Output the tracking results to Telemetry block ##########
if (interchange_iq)
{
if (trk_parameters.track_pilot)
{
// Note that data and pilot components are in quadrature. I and Q are interchanged
current_synchro_data.Prompt_I = static_cast<double>((*d_Prompt_Data).imag());
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt_Data).real());
}
else
{
current_synchro_data.Prompt_I = static_cast<double>((*d_Prompt).imag());
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt).real());
}
}
else
{
if (trk_parameters.track_pilot)
{
// Note that data and pilot components are in quadrature. I and Q are interchanged
current_synchro_data.Prompt_I = static_cast<double>((*d_Prompt_Data).real());
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt_Data).imag());
}
else
{
current_synchro_data.Prompt_I = static_cast<double>((*d_Prompt).real());
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt).imag());
}
}
current_synchro_data.Code_phase_samples = d_rem_code_phase_samples;
current_synchro_data.Carrier_phase_rads = d_acc_carrier_phase_rad;
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
current_synchro_data.Flag_valid_symbol_output = true;
current_synchro_data.correlation_length_ms = d_correlation_length_ms;
d_extend_correlation_symbols_count++;
if (d_extend_correlation_symbols_count == (trk_parameters.extend_correlation_symbols - 1))
{
d_extend_correlation_symbols_count = 0;
d_state = 4;
}
log_data(true);
break;
}
case 4: // narrow tracking
{
// Fill the acquisition data
current_synchro_data = *d_acquisition_gnss_synchro;
// perform a correlation step
do_correlation_step(in);
save_correlation_results();
// check lock status
if (!cn0_and_tracking_lock_status(d_code_period * static_cast<double>(trk_parameters.extend_correlation_symbols)))
{
clear_tracking_vars();
d_state = 0; // loss-of-lock detected
}
else
{
run_dll_pll();
update_tracking_vars();
// ########### Output the tracking results to Telemetry block ##########
if (interchange_iq)
{
if (trk_parameters.track_pilot)
{
// Note that data and pilot components are in quadrature. I and Q are interchanged
current_synchro_data.Prompt_I = static_cast<double>((*d_Prompt_Data).imag());
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt_Data).real());
}
else
{
current_synchro_data.Prompt_I = static_cast<double>((*d_Prompt).imag());
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt).real());
}
}
else
{
if (trk_parameters.track_pilot)
{
// Note that data and pilot components are in quadrature. I and Q are interchanged
current_synchro_data.Prompt_I = static_cast<double>((*d_Prompt_Data).real());
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt_Data).imag());
}
else
{
current_synchro_data.Prompt_I = static_cast<double>((*d_Prompt).real());
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt).imag());
}
}
current_synchro_data.Code_phase_samples = d_rem_code_phase_samples;
current_synchro_data.Carrier_phase_rads = d_acc_carrier_phase_rad;
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
current_synchro_data.Flag_valid_symbol_output = true;
current_synchro_data.correlation_length_ms = d_correlation_length_ms;
// enable write dump file this cycle (valid DLL/PLL cycle)
log_data(false);
// reset extended correlator
d_VE_accu = gr_complex(0.0, 0.0);
d_E_accu = gr_complex(0.0, 0.0);
d_P_accu = gr_complex(0.0, 0.0);
d_L_accu = gr_complex(0.0, 0.0);
d_VL_accu = gr_complex(0.0, 0.0);
if (d_enable_extended_integration)
{
d_state = 3; // new coherent integration (correlation time extension) cycle
}
}
}
}
consume_each(d_current_prn_length_samples);
d_sample_counter += static_cast<uint64_t>(d_current_prn_length_samples);
if (current_synchro_data.Flag_valid_symbol_output)
{
current_synchro_data.fs = static_cast<int64_t>(trk_parameters.fs_in);
current_synchro_data.Tracking_sample_counter = d_sample_counter;
*out[0] = current_synchro_data;
return 1;
}
return 0;
}
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