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

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/*!
* \file kf_tracking.cc
* \brief Implementation of a Kalman filter based tracking with optional Vector
* Tracking Loop message receiver block.
* \author Javier Arribas, 2020. jarribas(at)cttc.es
*
* -----------------------------------------------------------------------------
*
* Copyright (C) 2010-2020 (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.
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
* -----------------------------------------------------------------------------
*/
#include "kf_tracking.h"
#include "Beidou_B1I.h"
#include "Beidou_B3I.h"
#include "GPS_L1_CA.h"
#include "GPS_L2C.h"
#include "GPS_L5.h"
#include "Galileo_E1.h"
#include "Galileo_E5a.h"
#include "Galileo_E5b.h"
#include "MATH_CONSTANTS.h"
#include "beidou_b1i_signal_replica.h"
#include "beidou_b3i_signal_replica.h"
#include "galileo_e1_signal_replica.h"
#include "galileo_e5_signal_replica.h"
#include "galileo_e6_signal_replica.h"
#include "gnss_satellite.h"
#include "gnss_sdr_create_directory.h"
#include "gnss_sdr_filesystem.h"
#include "gnss_synchro.h"
#include "gps_l2c_signal_replica.h"
#include "gps_l5_signal_replica.h"
#include "gps_sdr_signal_replica.h"
#include "lock_detectors.h"
#include "tracking_discriminators.h"
#include "trackingcmd.h"
#include <glog/logging.h>
#include <gnuradio/io_signature.h> // for io_signature
#include <gnuradio/thread/thread.h> // for scoped_lock
#include <matio.h> // for Mat_VarCreate
#include <pmt/pmt_sugar.h> // for mp
#include <volk_gnsssdr/volk_gnsssdr.h>
#include <algorithm> // for fill_n
#include <array>
#include <cmath> // for fmod, round, floor
#include <exception> // for exception
#include <iostream> // for cout, cerr
#include <map>
#include <numeric>
#include <vector>
#if HAS_GENERIC_LAMBDA
#else
#include <boost/bind/bind.hpp>
#endif
#if PMT_USES_BOOST_ANY
#include <boost/any.hpp>
namespace wht = boost;
#else
#include <any>
namespace wht = std;
#endif
kf_tracking_sptr kf_make_tracking(const Kf_Conf &conf_)
{
return kf_tracking_sptr(new kf_tracking(conf_));
}
kf_tracking::kf_tracking(const Kf_Conf &conf_)
: gr::block("kf_tracking",
gr::io_signature::make(1, 1, sizeof(gr_complex)),
gr::io_signature::make(1, 1, sizeof(Gnss_Synchro))),
d_trk_parameters(conf_),
d_acquisition_gnss_synchro(nullptr),
d_signal_type(d_trk_parameters.signal),
d_code_chip_rate(0.0),
d_acq_code_phase_samples(0.0),
d_acq_carrier_doppler_hz(0.0),
d_current_correlation_time_s(0.0),
d_carr_phase_error_disc_hz(0.0),
d_code_error_disc_chips(0.0),
d_code_error_kf_chips(0.0),
d_code_freq_kf_chips_s(0.0),
d_carrier_phase_kf_rad(0.0),
d_carrier_doppler_kf_hz(0.0),
d_carrier_doppler_rate_kf_hz_s(0.0),
d_acc_carrier_phase_rad(0.0),
d_T_chip_seconds(0.0),
d_T_prn_seconds(0.0),
d_T_prn_samples(0.0),
d_K_blk_samples(0.0),
d_carrier_lock_test(1.0),
d_CN0_SNV_dB_Hz(0.0),
d_carrier_lock_threshold(d_trk_parameters.carrier_lock_th),
d_carrier_phase_step_rad(0.0),
d_carrier_phase_rate_step_rad(0.0),
d_code_phase_step_chips(0.0),
d_code_phase_rate_step_chips(0.0),
d_rem_code_phase_chips(0.0),
d_rem_code_phase_samples(0.0),
d_beta(0.0),
d_sample_counter(0ULL),
d_acq_sample_stamp(0ULL),
d_rem_carr_phase_rad(0.0),
d_channel(0U),
d_secondary_code_length(0U),
d_data_secondary_code_length(0U),
d_state(0),
d_current_prn_length_samples(static_cast<int32_t>(d_trk_parameters.vector_length)),
d_extend_correlation_symbols_count(0),
d_cn0_estimation_counter(0),
d_carrier_lock_fail_counter(0),
d_code_lock_fail_counter(0),
d_pull_in_transitory(true),
d_corrected_doppler(false),
d_interchange_iq(false),
d_veml(false),
d_cloop(true),
d_dump(d_trk_parameters.dump),
d_dump_mat(d_trk_parameters.dump_mat && d_dump),
d_acc_carrier_phase_initialized(false)
{
#if GNURADIO_GREATER_THAN_38
this->set_relative_rate(1, static_cast<uint64_t>(d_trk_parameters.vector_length));
#else
this->set_relative_rate(1.0 / static_cast<double>(d_trk_parameters.vector_length));
#endif
// prevent telemetry symbols accumulation in output buffers
this->set_max_noutput_items(1);
// Telemetry bit synchronization message port input
this->message_port_register_out(pmt::mp("events"));
// Telemetry message port input
this->message_port_register_in(pmt::mp("telemetry_to_trk"));
this->set_msg_handler(
pmt::mp("telemetry_to_trk"),
#if HAS_GENERIC_LAMBDA
[this](auto &&PH1) { msg_handler_telemetry_to_trk(PH1); });
#else
#if USE_BOOST_BIND_PLACEHOLDERS
boost::bind(&kf_tracking::msg_handler_telemetry_to_trk, this, boost::placeholders::_1));
#else
boost::bind(&kf_tracking::msg_handler_telemetry_to_trk, this, _1));
#endif
#endif
// PVT message port input
this->message_port_register_in(pmt::mp("pvt_to_trk"));
this->set_msg_handler(
pmt::mp("pvt_to_trk"),
#if HAS_GENERIC_LAMBDA
[this](auto &&PH1) { msg_handler_pvt_to_trk(PH1); });
#else
#if USE_BOOST_BIND_PLACEHOLDERS
boost::bind(&kf_tracking::msg_handler_pvt_to_trk, this, boost::placeholders::_1));
#else
boost::bind(&kf_tracking::msg_handler_pvt_to_trk, this, _1));
#endif
#endif
// initialize internal vars
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["7X"] = "E5b";
map_signal_pretty_name["L5"] = "L5";
map_signal_pretty_name["B1"] = "B1I";
map_signal_pretty_name["B3"] = "B3I";
d_signal_pretty_name = map_signal_pretty_name[d_signal_type];
if (d_trk_parameters.system == 'G')
{
d_systemName = "GPS";
if (d_signal_type == "1C")
{
d_signal_carrier_freq = GPS_L1_FREQ_HZ;
d_code_period = GPS_L1_CA_CODE_PERIOD_S;
d_code_chip_rate = GPS_L1_CA_CODE_RATE_CPS;
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_code_length_chips = static_cast<int32_t>(GPS_L1_CA_CODE_LENGTH_CHIPS);
// GPS L1 C/A does not have pilot component nor secondary code
d_secondary = false;
d_trk_parameters.track_pilot = false;
d_trk_parameters.slope = 1.0;
d_trk_parameters.spc = d_trk_parameters.early_late_space_chips;
d_trk_parameters.y_intercept = 1.0;
// symbol integration: 20 trk symbols (20 ms) = 1 tlm bit
// set the preamble in the secondary code acquisition to obtain tlm symbol synchronization
d_secondary_code_length = static_cast<uint32_t>(GPS_CA_PREAMBLE_LENGTH_SYMBOLS);
d_secondary_code_string = GPS_CA_PREAMBLE_SYMBOLS_STR;
d_symbols_per_bit = GPS_CA_TELEMETRY_SYMBOLS_PER_BIT;
}
else if (d_signal_type == "2S")
{
d_signal_carrier_freq = GPS_L2_FREQ_HZ;
d_code_period = GPS_L2_M_PERIOD_S;
d_code_chip_rate = GPS_L2_M_CODE_RATE_CPS;
d_code_length_chips = static_cast<int32_t>(GPS_L2_M_CODE_LENGTH_CHIPS);
// GPS L2C has 1 trk symbol (20 ms) per tlm bit, no symbol integration required
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;
d_trk_parameters.track_pilot = false;
d_trk_parameters.slope = 1.0;
d_trk_parameters.spc = d_trk_parameters.early_late_space_chips;
d_trk_parameters.y_intercept = 1.0;
}
else if (d_signal_type == "L5")
{
d_signal_carrier_freq = GPS_L5_FREQ_HZ;
d_code_period = GPS_L5I_PERIOD_S;
d_code_chip_rate = GPS_L5I_CODE_RATE_CPS;
// symbol integration: 10 trk symbols (10 ms) = 1 tlm bit
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<int32_t>(GPS_L5I_CODE_LENGTH_CHIPS);
d_secondary = true;
d_trk_parameters.slope = 1.0;
d_trk_parameters.spc = d_trk_parameters.early_late_space_chips;
d_trk_parameters.y_intercept = 1.0;
if (d_trk_parameters.track_pilot)
{
// synchronize pilot secondary code
d_secondary_code_length = static_cast<uint32_t>(GPS_L5Q_NH_CODE_LENGTH);
d_secondary_code_string = GPS_L5Q_NH_CODE_STR;
// remove data secondary code
// remove Neuman-Hofman Code (see IS-GPS-705D)
d_data_secondary_code_length = static_cast<uint32_t>(GPS_L5I_NH_CODE_LENGTH);
d_data_secondary_code_string = GPS_L5I_NH_CODE_STR;
d_signal_pretty_name = d_signal_pretty_name + "Q";
}
else
{
// synchronize and remove data secondary code
// remove Neuman-Hofman Code (see IS-GPS-705D)
d_secondary_code_length = static_cast<uint32_t>(GPS_L5I_NH_CODE_LENGTH);
d_secondary_code_string = GPS_L5I_NH_CODE_STR;
d_signal_pretty_name = d_signal_pretty_name + "I";
d_interchange_iq = true;
}
}
else
{
LOG(WARNING) << "Invalid Signal argument when instantiating tracking blocks";
std::cerr << "Invalid Signal argument when instantiating tracking blocks\n";
d_correlation_length_ms = 1;
d_secondary = false;
d_signal_carrier_freq = 0.0;
d_code_period = 0.0;
d_code_length_chips = 0;
d_code_samples_per_chip = 0U;
d_symbols_per_bit = 0;
}
}
else if (d_trk_parameters.system == 'E')
{
d_systemName = "Galileo";
if (d_signal_type == "1B")
{
d_signal_carrier_freq = GALILEO_E1_FREQ_HZ;
d_code_period = GALILEO_E1_CODE_PERIOD_S;
d_code_chip_rate = GALILEO_E1_CODE_CHIP_RATE_CPS;
d_code_length_chips = static_cast<int32_t>(GALILEO_E1_B_CODE_LENGTH_CHIPS);
// Galileo E1b has 1 trk symbol (4 ms) per tlm bit, no symbol integration required
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;
d_trk_parameters.spc = d_trk_parameters.early_late_space_chips;
d_trk_parameters.slope = static_cast<float>(-CalculateSlopeAbs(&SinBocCorrelationFunction<1, 1>, d_trk_parameters.spc));
d_trk_parameters.y_intercept = static_cast<float>(GetYInterceptAbs(&SinBocCorrelationFunction<1, 1>, d_trk_parameters.spc));
if (d_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 = GALILEO_E1_C_SECONDARY_CODE;
d_signal_pretty_name = d_signal_pretty_name + "C";
}
else
{
d_secondary = false;
d_signal_pretty_name = d_signal_pretty_name + "B";
}
// Note that E1-B and E1-C are in anti-phase, NOT IN QUADRATURE. See Galileo ICD.
}
else if (d_signal_type == "5X")
{
d_signal_carrier_freq = GALILEO_E5A_FREQ_HZ;
d_code_period = GALILEO_E5A_CODE_PERIOD_S;
d_code_chip_rate = GALILEO_E5A_CODE_CHIP_RATE_CPS;
d_symbols_per_bit = 20;
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_code_length_chips = static_cast<int32_t>(GALILEO_E5A_CODE_LENGTH_CHIPS);
d_secondary = true;
d_trk_parameters.slope = 1.0;
d_trk_parameters.spc = d_trk_parameters.early_late_space_chips;
d_trk_parameters.y_intercept = 1.0;
if (d_trk_parameters.track_pilot)
{
// synchronize pilot secondary code
d_secondary_code_length = static_cast<uint32_t>(GALILEO_E5A_Q_SECONDARY_CODE_LENGTH);
d_signal_pretty_name = d_signal_pretty_name + "Q";
// remove data secondary code
d_data_secondary_code_length = static_cast<uint32_t>(GALILEO_E5A_I_SECONDARY_CODE_LENGTH);
d_data_secondary_code_string = GALILEO_E5A_I_SECONDARY_CODE;
}
else
{
// synchronize and remove data secondary code
d_secondary_code_length = static_cast<uint32_t>(GALILEO_E5A_I_SECONDARY_CODE_LENGTH);
d_secondary_code_string = GALILEO_E5A_I_SECONDARY_CODE;
d_signal_pretty_name = d_signal_pretty_name + "I";
d_interchange_iq = true;
}
}
else if (d_signal_type == "7X")
{
d_signal_carrier_freq = GALILEO_E5B_FREQ_HZ;
d_code_period = GALILEO_E5B_CODE_PERIOD_S;
d_code_chip_rate = GALILEO_E5B_CODE_CHIP_RATE_CPS;
d_symbols_per_bit = 4;
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_code_length_chips = static_cast<int32_t>(GALILEO_E5B_CODE_LENGTH_CHIPS);
d_secondary = true;
d_trk_parameters.slope = 1.0;
d_trk_parameters.spc = d_trk_parameters.early_late_space_chips;
d_trk_parameters.y_intercept = 1.0;
if (d_trk_parameters.track_pilot)
{
// synchronize pilot secondary code
d_secondary_code_length = static_cast<uint32_t>(GALILEO_E5B_Q_SECONDARY_CODE_LENGTH);
d_signal_pretty_name = d_signal_pretty_name + "Q";
// remove data secondary code
d_data_secondary_code_length = static_cast<uint32_t>(GALILEO_E5B_I_SECONDARY_CODE_LENGTH);
d_data_secondary_code_string = GALILEO_E5B_I_SECONDARY_CODE;
}
else
{
// synchronize and remove data secondary code
d_secondary_code_length = static_cast<uint32_t>(GALILEO_E5B_I_SECONDARY_CODE_LENGTH);
d_secondary_code_string = GALILEO_E5B_I_SECONDARY_CODE;
d_signal_pretty_name = d_signal_pretty_name + "I";
d_interchange_iq = true;
}
}
else
{
LOG(WARNING) << "Invalid Signal argument when instantiating tracking blocks";
std::cout << "Invalid Signal argument when instantiating tracking blocks\n";
d_correlation_length_ms = 1;
d_secondary = false;
d_signal_carrier_freq = 0.0;
d_code_period = 0.0;
d_code_length_chips = 0;
d_code_samples_per_chip = 0U;
d_symbols_per_bit = 0;
}
}
else if (d_trk_parameters.system == 'C')
{
d_systemName = "Beidou";
if (d_signal_type == "B1")
{
// GEO Satellites use different secondary code
d_signal_carrier_freq = BEIDOU_B1I_FREQ_HZ;
d_code_period = BEIDOU_B1I_CODE_PERIOD_S;
d_code_chip_rate = BEIDOU_B1I_CODE_RATE_CPS;
d_code_length_chips = static_cast<int32_t>(BEIDOU_B1I_CODE_LENGTH_CHIPS);
d_symbols_per_bit = BEIDOU_B1I_TELEMETRY_SYMBOLS_PER_BIT; // todo: enable after fixing beidou symbol synchronization
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_secondary = true;
d_trk_parameters.track_pilot = false;
d_trk_parameters.slope = 1.0;
d_trk_parameters.spc = d_trk_parameters.early_late_space_chips;
d_trk_parameters.y_intercept = 1.0;
// synchronize and remove data secondary code
d_secondary_code_length = static_cast<uint32_t>(BEIDOU_B1I_SECONDARY_CODE_LENGTH);
d_secondary_code_string = BEIDOU_B1I_SECONDARY_CODE_STR;
d_data_secondary_code_length = static_cast<uint32_t>(BEIDOU_B1I_SECONDARY_CODE_LENGTH);
d_data_secondary_code_string = BEIDOU_B1I_SECONDARY_CODE_STR;
}
else if (d_signal_type == "B3")
{
// GEO Satellites use different secondary code
d_signal_carrier_freq = BEIDOU_B3I_FREQ_HZ;
d_code_period = BEIDOU_B3I_CODE_PERIOD_S;
d_code_chip_rate = BEIDOU_B3I_CODE_RATE_CPS;
d_code_length_chips = static_cast<int32_t>(BEIDOU_B3I_CODE_LENGTH_CHIPS);
d_symbols_per_bit = BEIDOU_B3I_TELEMETRY_SYMBOLS_PER_BIT; // todo: enable after fixing beidou symbol synchronization
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_secondary = false;
d_trk_parameters.track_pilot = false;
d_trk_parameters.slope = 1.0;
d_trk_parameters.spc = d_trk_parameters.early_late_space_chips;
d_trk_parameters.y_intercept = 1.0;
d_secondary_code_length = static_cast<uint32_t>(BEIDOU_B3I_SECONDARY_CODE_LENGTH);
d_secondary_code_string = BEIDOU_B3I_SECONDARY_CODE_STR;
d_data_secondary_code_length = static_cast<uint32_t>(BEIDOU_B3I_SECONDARY_CODE_LENGTH);
d_data_secondary_code_string = BEIDOU_B3I_SECONDARY_CODE_STR;
}
else
{
LOG(WARNING) << "Invalid Signal argument when instantiating tracking blocks";
std::cout << "Invalid Signal argument when instantiating tracking blocks\n";
d_correlation_length_ms = 1;
d_secondary = 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\n";
d_correlation_length_ms = 1;
d_secondary = false;
d_signal_carrier_freq = 1.0;
d_code_period = 0.0;
d_code_length_chips = 0;
d_code_samples_per_chip = 0U;
d_symbols_per_bit = 0;
}
d_beta = d_code_chip_rate / d_signal_carrier_freq;
// Initialization of local code replica
// Get space for a vector with the sinboc(1,1) replica sampled 2x/chip
d_tracking_code.resize(2 * d_code_length_chips, 0.0);
// 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 = volk_gnsssdr::vector<gr_complex>(d_n_correlator_taps);
d_local_code_shift_chips = volk_gnsssdr::vector<float>(d_n_correlator_taps);
// 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] = -d_trk_parameters.very_early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[1] = -d_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] = d_trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[4] = d_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] = -d_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] = d_trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_prompt_data_shift = &d_local_code_shift_chips[1];
}
d_multicorrelator_cpu.init(static_cast<int>(2 * d_trk_parameters.vector_length), d_n_correlator_taps);
if (d_trk_parameters.extend_correlation_symbols > 1)
{
d_enable_extended_integration = true;
}
else
{
d_enable_extended_integration = false;
d_trk_parameters.extend_correlation_symbols = 1;
}
// Enable Data component prompt correlator (slave to Pilot prompt) if tracking uses Pilot signal
if (d_trk_parameters.track_pilot)
{
// Extra correlator for the data component
d_correlator_data_cpu.init(static_cast<int>(2 * d_trk_parameters.vector_length), 1);
d_correlator_data_cpu.set_high_dynamics_resampler(d_trk_parameters.high_dyn);
d_data_code.resize(2 * d_code_length_chips, 0.0);
}
// --- Initializations ---
d_Prompt_circular_buffer.set_capacity(d_secondary_code_length);
d_multicorrelator_cpu.set_high_dynamics_resampler(d_trk_parameters.high_dyn);
// Initial code frequency basis of NCO
d_code_freq_kf_chips_s = d_code_chip_rate;
// CN0 estimation and lock detector buffers
d_Prompt_buffer = volk_gnsssdr::vector<gr_complex>(d_trk_parameters.cn0_samples);
d_Prompt_Data = volk_gnsssdr::vector<gr_complex>(1);
d_cn0_smoother = Exponential_Smoother();
d_cn0_smoother.set_alpha(d_trk_parameters.cn0_smoother_alpha);
if (d_code_period > 0.0)
{
d_cn0_smoother.set_samples_for_initialization(d_trk_parameters.cn0_smoother_samples / static_cast<int>(d_code_period * 1000.0));
}
d_carrier_lock_test_smoother = Exponential_Smoother();
d_carrier_lock_test_smoother.set_alpha(d_trk_parameters.carrier_lock_test_smoother_alpha);
d_carrier_lock_test_smoother.set_min_value(-1.0);
d_carrier_lock_test_smoother.set_offset(0.0);
d_carrier_lock_test_smoother.set_samples_for_initialization(d_trk_parameters.carrier_lock_test_smoother_samples);
clear_tracking_vars();
if (d_trk_parameters.smoother_length > 0)
{
d_carr_ph_history.set_capacity(d_trk_parameters.smoother_length * 2);
d_code_ph_history.set_capacity(d_trk_parameters.smoother_length * 2);
}
else
{
d_carr_ph_history.set_capacity(1);
d_code_ph_history.set_capacity(1);
}
if (d_dump)
{
d_dump_filename = d_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 + fs::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?\n";
d_dump = false;
}
}
}
void kf_tracking::forecast(int noutput_items,
gr_vector_int &ninput_items_required)
{
if (noutput_items != 0)
{
ninput_items_required[0] = static_cast<int32_t>(d_trk_parameters.vector_length) * 2;
}
}
void kf_tracking::msg_handler_telemetry_to_trk(const pmt::pmt_t &msg)
{
try
{
if (pmt::any_ref(msg).type().hash_code() == d_int_type_hash_code)
{
const int tlm_event = wht::any_cast<int>(pmt::any_ref(msg));
if (tlm_event == 1)
{
DLOG(INFO) << "Telemetry fault received in ch " << this->d_channel;
gr::thread::scoped_lock lock(d_setlock);
d_carrier_lock_fail_counter = 200000; // force loss-of-lock condition
}
}
}
catch (const wht::bad_any_cast &e)
{
LOG(WARNING) << "msg_handler_telemetry_to_trk Bad any_cast: " << e.what();
}
}
void kf_tracking::msg_handler_pvt_to_trk(const pmt::pmt_t &msg)
{
try
{
if (pmt::any_ref(msg).type().hash_code() == typeid(const std::shared_ptr<TrackingCmd>).hash_code())
{
const auto cmd = wht::any_cast<const std::shared_ptr<TrackingCmd>>(pmt::any_ref(msg));
// std::cout << "RX pvt-to-trk cmd with delay: "
// << static_cast<double>(nitems_read(0) - cmd->sample_counter) / d_trk_parameters.fs_in << " [s]\n";
}
else
{
std::cout << "hash code not match\n";
}
}
catch (const wht::bad_any_cast &e)
{
LOG(WARNING) << "msg_handler_pvt_to_trk Bad any_cast: " << e.what();
}
}
void kf_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_kf_hz = d_acq_carrier_doppler_hz;
d_carrier_phase_step_rad = TWO_PI * d_carrier_doppler_kf_hz / d_trk_parameters.fs_in;
d_carrier_phase_rate_step_rad = 0.0;
d_carr_ph_history.clear();
d_code_ph_history.clear();
std::array<char, 3> Signal_{};
Signal_[0] = d_acquisition_gnss_synchro->Signal[0];
Signal_[1] = d_acquisition_gnss_synchro->Signal[1];
Signal_[2] = d_acquisition_gnss_synchro->Signal[2];
if (d_systemName == "GPS" and d_signal_type == "1C")
{
gps_l1_ca_code_gen_float(d_tracking_code, d_acquisition_gnss_synchro->PRN, 0);
}
else if (d_systemName == "GPS" and d_signal_type == "2S")
{
gps_l2c_m_code_gen_float(d_tracking_code, d_acquisition_gnss_synchro->PRN);
}
else if (d_systemName == "GPS" and d_signal_type == "L5")
{
if (d_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);
d_correlator_data_cpu.set_local_code_and_taps(d_code_length_chips, d_data_code.data(), d_prompt_data_shift);
}
else
{
gps_l5i_code_gen_float(d_tracking_code, d_acquisition_gnss_synchro->PRN);
}
}
else if (d_systemName == "Galileo" and d_signal_type == "1B")
{
if (d_trk_parameters.track_pilot)
{
const std::array<char, 3> pilot_signal = {{'1', 'C', '\0'}};
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, Signal_, d_acquisition_gnss_synchro->PRN);
d_Prompt_Data[0] = gr_complex(0.0, 0.0);
d_correlator_data_cpu.set_local_code_and_taps(d_code_samples_per_chip * d_code_length_chips, d_data_code.data(), d_prompt_data_shift);
}
else
{
galileo_e1_code_gen_sinboc11_float(d_tracking_code, Signal_, d_acquisition_gnss_synchro->PRN);
}
}
else if (d_systemName == "Galileo" and d_signal_type == "5X")
{
volk_gnsssdr::vector<gr_complex> aux_code(d_code_length_chips);
const std::array<char, 3> signal_type_ = {{'5', 'X', '\0'}};
galileo_e5_a_code_gen_complex_primary(aux_code, d_acquisition_gnss_synchro->PRN, signal_type_);
if (d_trk_parameters.track_pilot)
{
d_secondary_code_string = GALILEO_E5A_Q_SECONDARY_CODE[d_acquisition_gnss_synchro->PRN - 1];
for (int32_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);
d_correlator_data_cpu.set_local_code_and_taps(d_code_length_chips, d_data_code.data(), d_prompt_data_shift);
}
else
{
for (int32_t i = 0; i < d_code_length_chips; i++)
{
d_tracking_code[i] = aux_code[i].real();
}
}
}
else if (d_systemName == "Galileo" and d_signal_type == "7X")
{
volk_gnsssdr::vector<gr_complex> aux_code(d_code_length_chips);
const std::array<char, 3> signal_type_ = {{'7', 'X', '\0'}};
galileo_e5_b_code_gen_complex_primary(aux_code, d_acquisition_gnss_synchro->PRN, signal_type_);
if (d_trk_parameters.track_pilot)
{
d_secondary_code_string = GALILEO_E5B_Q_SECONDARY_CODE[d_acquisition_gnss_synchro->PRN - 1];
for (int32_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 (E5bI + E5bsQ)
}
d_Prompt_Data[0] = gr_complex(0.0, 0.0);
d_correlator_data_cpu.set_local_code_and_taps(d_code_length_chips, d_data_code.data(), d_prompt_data_shift);
}
else
{
for (int32_t i = 0; i < d_code_length_chips; i++)
{
d_tracking_code[i] = aux_code[i].real();
}
}
}
else if (d_systemName == "Beidou" and d_signal_type == "B1")
{
beidou_b1i_code_gen_float(d_tracking_code, d_acquisition_gnss_synchro->PRN, 0);
// GEO Satellites use different secondary code
if (d_acquisition_gnss_synchro->PRN > 0 and d_acquisition_gnss_synchro->PRN < 6)
{
d_symbols_per_bit = BEIDOU_B1I_GEO_TELEMETRY_SYMBOLS_PER_BIT; // todo: enable after fixing beidou symbol synchronization
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_secondary = false;
d_trk_parameters.track_pilot = false;
// set the preamble in the secondary code acquisition
d_secondary_code_length = static_cast<uint32_t>(BEIDOU_B1I_GEO_PREAMBLE_LENGTH_SYMBOLS);
d_secondary_code_string = BEIDOU_B1I_GEO_PREAMBLE_SYMBOLS_STR;
d_data_secondary_code_length = 0;
d_Prompt_circular_buffer.set_capacity(d_secondary_code_length);
}
else
{
d_symbols_per_bit = BEIDOU_B1I_TELEMETRY_SYMBOLS_PER_BIT; // todo: enable after fixing beidou symbol synchronization
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_secondary = true;
d_trk_parameters.track_pilot = false;
// synchronize and remove data secondary code
d_secondary_code_length = static_cast<uint32_t>(BEIDOU_B1I_SECONDARY_CODE_LENGTH);
d_secondary_code_string = BEIDOU_B1I_SECONDARY_CODE_STR;
d_data_secondary_code_length = static_cast<uint32_t>(BEIDOU_B1I_SECONDARY_CODE_LENGTH);
d_data_secondary_code_string = BEIDOU_B1I_SECONDARY_CODE_STR;
d_Prompt_circular_buffer.set_capacity(d_secondary_code_length);
}
}
else if (d_systemName == "Beidou" and d_signal_type == "B3")
{
beidou_b3i_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 = BEIDOU_B3I_GEO_TELEMETRY_SYMBOLS_PER_BIT; // todo: enable after fixing beidou symbol synchronization
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_secondary = false;
d_trk_parameters.track_pilot = false;
// set the preamble in the secondary code acquisition
d_secondary_code_length = static_cast<uint32_t>(BEIDOU_B3I_GEO_PREAMBLE_LENGTH_SYMBOLS);
d_secondary_code_string = BEIDOU_B3I_GEO_PREAMBLE_SYMBOLS_STR;
d_data_secondary_code_length = 0;
d_Prompt_circular_buffer.set_capacity(d_secondary_code_length);
}
else
{
d_symbols_per_bit = BEIDOU_B3I_TELEMETRY_SYMBOLS_PER_BIT; // todo: enable after fixing beidou symbol synchronization
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_secondary = true;
d_trk_parameters.track_pilot = false;
// synchronize and remove data secondary code
d_secondary_code_length = static_cast<uint32_t>(BEIDOU_B3I_SECONDARY_CODE_LENGTH);
d_secondary_code_string = BEIDOU_B3I_SECONDARY_CODE_STR;
d_data_secondary_code_length = static_cast<uint32_t>(BEIDOU_B3I_SECONDARY_CODE_LENGTH);
d_data_secondary_code_string = BEIDOU_B3I_SECONDARY_CODE_STR;
d_Prompt_circular_buffer.set_capacity(d_secondary_code_length);
}
}
d_multicorrelator_cpu.set_local_code_and_taps(d_code_samples_per_chip * d_code_length_chips, d_tracking_code.data(), d_local_code_shift_chips.data());
std::fill_n(d_correlator_outs.begin(), d_n_correlator_taps, gr_complex(0.0, 0.0));
d_carrier_lock_fail_counter = 0;
d_code_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] = -d_trk_parameters.very_early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[1] = -d_trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[3] = d_trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[4] = d_trk_parameters.very_early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
}
else
{
d_local_code_shift_chips[0] = -d_trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[2] = d_trk_parameters.early_late_space_chips * static_cast<float>(d_code_samples_per_chip);
}
d_current_correlation_time_s = d_code_period;
// Initialize tracking ==========================================
// DEBUG OUTPUT
std::cout << "Tracking of " << d_systemName << " " << d_signal_pretty_name << " signal started on channel " << d_channel << " for satellite " << Gnss_Satellite(d_systemName, d_acquisition_gnss_synchro->PRN) << '\n';
DLOG(INFO) << "Starting tracking of satellite " << Gnss_Satellite(d_systemName, d_acquisition_gnss_synchro->PRN) << " on channel " << d_channel;
// enable tracking pull-in
d_state = 1;
d_cloop = true;
d_pull_in_transitory = true;
d_Prompt_circular_buffer.clear();
d_corrected_doppler = false;
d_acc_carrier_phase_initialized = false;
}
void kf_tracking::init_kf(double acq_code_phase_chips, double acq_doppler_hz)
{
// Kalman Filter class variables
const double Ti = d_current_correlation_time_s;
const double TiTi = Ti * Ti;
d_F = {{1.0, 0.0, d_beta * Ti, d_beta * TiTi / 2.0},
{0.0, 1.0, 2.0 * GNSS_PI * Ti, GNSS_PI * TiTi},
{0.0, 0.0, 1.0, Ti},
{0.0, 0.0, 0.0, 1.0}};
d_H = {{1.0, 0.0, -d_beta * Ti / 2.0, d_beta * TiTi / 6.0},
{0.0, 1.0, -GNSS_PI * Ti, GNSS_PI * TiTi / 3.0}};
d_R = {{pow(d_trk_parameters.code_disc_sd_chips, 2.0), 0.0},
{0.0, pow(d_trk_parameters.carrier_disc_sd_rads, 2.0)}};
// system covariance matrix (static)
d_Q = {{pow(d_trk_parameters.code_phase_sd_chips, 2.0), 0.0, 0.0, 0.0},
{0.0, pow(d_trk_parameters.carrier_phase_sd_rad, 2.0), 0.0, 0.0},
{0.0, 0.0, pow(d_trk_parameters.carrier_freq_sd_hz, 2.0), 0.0},
{0.0, 0.0, 0.0, pow(d_trk_parameters.carrier_freq_rate_sd_hz_s, 2.0)}};
// initial Kalman covariance matrix
d_P_old_old = {{pow(d_trk_parameters.init_code_phase_sd_chips, 2.0), 0.0, 0.0, 0.0},
{0.0, pow(d_trk_parameters.init_carrier_phase_sd_rad, 2.0), 0.0, 0.0},
{0.0, 0.0, pow(d_trk_parameters.init_carrier_freq_sd_hz, 2.0), 0.0},
{0.0, 0.0, 0.0, pow(d_trk_parameters.init_carrier_freq_rate_sd_hz_s, 2.0)}};
// states: code_phase_chips, carrier_phase_rads, carrier_freq_hz, carrier_freq_rate_hz_s
d_x_old_old = {acq_code_phase_chips, 0.0, acq_doppler_hz, 0.0};
DLOG(INFO) << "F: " << d_F;
DLOG(INFO) << "H: " << d_H;
DLOG(INFO) << "R: " << d_R;
DLOG(INFO) << "Q: " << d_Q;
DLOG(INFO) << "P: " << d_P_old_old;
DLOG(INFO) << "x: " << d_x_old_old;
}
void kf_tracking::update_kf_narrow_integration_time()
{
// Kalman Filter class variables
const double Ti = d_current_correlation_time_s;
const double TiTi = Ti * Ti;
arma::mat Qnew = arma::zeros(4, 4);
for (int i = 0; i < d_trk_parameters.extend_correlation_symbols; i++)
{
Qnew += d_F * d_Q * d_F.t();
d_Q = d_F * d_Q * d_F.t();
}
d_Q = Qnew;
// state vector: code_phase_chips, carrier_phase_rads, carrier_freq_hz, carrier_freq_rate_hz
d_F = {{1.0, 0.0, d_beta * Ti, d_beta * TiTi / 2.0},
{0.0, 1.0, 2.0 * GNSS_PI * Ti, GNSS_PI * TiTi},
{0.0, 0.0, 1.0, Ti},
{0.0, 0.0, 0.0, 1.0}};
d_H = {{1.0, 0.0, -d_beta * Ti / 2.0, d_beta * TiTi / 6.0},
{0.0, 1.0, -GNSS_PI * Ti, GNSS_PI * TiTi / 3.0}};
const double CN0_lin = pow(10.0, d_CN0_SNV_dB_Hz / 10.0); // CN0 in Hz
const double CN0_lin_Ti = CN0_lin * Ti;
const double Sigma2_Phase = (1.0 / (2.0 * CN0_lin_Ti)) * (1.0 + 1.0 / (2.0 * CN0_lin_Ti));
const double Sigma2_Tau = (1.0 / CN0_lin_Ti) * (d_trk_parameters.spc + (d_trk_parameters.spc / (1.0 - d_trk_parameters.spc)) * (1.0 / (2.0 * CN0_lin_Ti)));
d_R = {{Sigma2_Tau, 0.0},
{0.0, Sigma2_Phase}};
DLOG(INFO) << "Fu: " << d_F;
DLOG(INFO) << "Hu: " << d_H;
DLOG(INFO) << "Ru: " << d_R;
DLOG(INFO) << "Qu: " << d_Q;
DLOG(INFO) << "Pu: " << d_P_old_old;
DLOG(INFO) << "xu: " << d_x_old_old;
}
void kf_tracking::update_kf_cn0(double current_cn0_dbhz)
{
// Kalman Filter class variables
const double Ti = d_current_correlation_time_s; // d_correlation_length_ms * 0.001;
const double TiTi = Ti * Ti;
d_H = {{1.0, 0.0, -d_beta * Ti / 2.0, d_beta * TiTi / 6.0},
{0.0, 1.0, -GNSS_PI * Ti, GNSS_PI * TiTi / 3.0}};
// Phase noise variance
const double CN0_lin = pow(10.0, current_cn0_dbhz / 10.0); // CN0 in Hz
const double CN0_lin_Ti = CN0_lin * Ti;
const double Sigma2_Phase = (1.0 / (2.0 * CN0_lin_Ti)) * (1.0 + 1.0 / (2.0 * CN0_lin_Ti));
const double Sigma2_Tau = (1.0 / CN0_lin_Ti) * (d_trk_parameters.spc + (d_trk_parameters.spc / (1.0 - d_trk_parameters.spc)) * (1.0 / (2.0 * CN0_lin_Ti)));
d_R = {{Sigma2_Tau, 0.0},
{0.0, Sigma2_Phase}};
}
kf_tracking::~kf_tracking()
{
if (d_dump_file.is_open())
{
try
{
d_dump_file.close();
}
catch (const std::exception &ex)
{
LOG(WARNING) << "Exception in Tracking block 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
{
if (d_trk_parameters.track_pilot)
{
d_correlator_data_cpu.free();
}
d_multicorrelator_cpu.free();
}
catch (const std::exception &ex)
{
LOG(WARNING) << "Exception in Tracking block destructor: " << ex.what();
}
}
bool kf_tracking::acquire_secondary()
{
// ******* preamble correlation ********
int32_t corr_value = 0;
for (uint32_t i = 0; i < d_secondary_code_length; i++)
{
if (d_Prompt_circular_buffer[i].real() < 0.0) // symbols clipping
{
if (d_secondary_code_string[i] == '0')
{
corr_value++;
}
else
{
corr_value--;
}
}
else
{
if (d_secondary_code_string[i] == '0')
{
corr_value--;
}
else
{
corr_value++;
}
}
}
if (abs(corr_value) == static_cast<int32_t>(d_secondary_code_length))
{
return true;
}
return false;
}
bool kf_tracking::cn0_and_tracking_lock_status(double coh_integration_time_s)
{
// ####### CN0 ESTIMATION AND LOCK DETECTORS ######
if (d_cn0_estimation_counter < d_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_Prompt_buffer[d_cn0_estimation_counter % d_trk_parameters.cn0_samples] = d_P_accu;
d_cn0_estimation_counter++;
// Code lock indicator
const float d_CN0_SNV_dB_Hz_raw = cn0_m2m4_estimator(d_Prompt_buffer.data(), d_trk_parameters.cn0_samples, static_cast<float>(coh_integration_time_s));
d_CN0_SNV_dB_Hz = d_cn0_smoother.smooth(d_CN0_SNV_dB_Hz_raw);
// Carrier lock indicator
d_carrier_lock_test = d_carrier_lock_test_smoother.smooth(carrier_lock_detector(d_Prompt_buffer.data(), 1));
// Loss of lock detection
if (!d_pull_in_transitory)
{
if (d_carrier_lock_test < d_carrier_lock_threshold)
{
d_carrier_lock_fail_counter++;
}
else
{
if (d_carrier_lock_fail_counter > 0)
{
d_carrier_lock_fail_counter--;
}
}
if (d_CN0_SNV_dB_Hz < d_trk_parameters.cn0_min)
{
d_code_lock_fail_counter++;
}
else
{
if (d_code_lock_fail_counter > 0)
{
d_code_lock_fail_counter--;
}
}
}
if (d_carrier_lock_fail_counter > d_trk_parameters.max_carrier_lock_fail or d_code_lock_fail_counter > d_trk_parameters.max_code_lock_fail)
{
std::cout << "Loss of lock in channel " << d_channel << "!\n";
LOG(INFO) << "Loss of lock in channel " << d_channel
<< " (carrier_lock_fail_counter:" << d_carrier_lock_fail_counter
<< " code_lock_fail_counter : " << d_code_lock_fail_counter << ")";
this->message_port_pub(pmt::mp("events"), pmt::from_long(3)); // 3 -> loss of lock
d_carrier_lock_fail_counter = 0;
d_code_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 kf_tracking::do_correlation_step(const gr_complex *input_samples)
{
// ################# CARRIER WIPEOFF AND CORRELATORS ##############################
// perform carrier wipe-off and compute Early, Prompt and Late correlation
d_multicorrelator_cpu.set_input_output_vectors(d_correlator_outs.data(), input_samples);
d_multicorrelator_cpu.Carrier_wipeoff_multicorrelator_resampler(
d_rem_carr_phase_rad,
static_cast<float>(d_carrier_phase_step_rad), static_cast<float>(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),
d_trk_parameters.vector_length);
// DATA CORRELATOR (if tracking tracks the pilot signal)
if (d_trk_parameters.track_pilot)
{
d_correlator_data_cpu.set_input_output_vectors(d_Prompt_Data.data(), input_samples);
d_correlator_data_cpu.Carrier_wipeoff_multicorrelator_resampler(
d_rem_carr_phase_rad,
static_cast<float>(d_carrier_phase_step_rad), static_cast<float>(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),
d_trk_parameters.vector_length);
}
}
void kf_tracking::run_Kf()
{
// Carrier discriminator
if (d_cloop)
{
// Costas loop discriminator, insensitive to 180 deg phase transitions
d_carr_phase_error_disc_hz = pll_cloop_two_quadrant_atan(d_P_accu) / TWO_PI;
}
else
{
// Secondary code acquired. No symbols transition should be present in the signal
d_carr_phase_error_disc_hz = pll_four_quadrant_atan(d_P_accu) / TWO_PI;
}
// Code discriminator
if (d_veml)
{
d_code_error_disc_chips = dll_nc_vemlp_normalized(d_VE_accu, d_E_accu, d_L_accu, d_VL_accu); // [chips/Ti]
}
else
{
d_code_error_disc_chips = dll_nc_e_minus_l_normalized(d_E_accu, d_L_accu, d_trk_parameters.spc, d_trk_parameters.slope, d_trk_parameters.y_intercept); // [chips/Ti]
}
// Kalman loop
// Prediction
d_x_new_old = d_F * d_x_old_old;
d_P_new_old = d_F * d_P_old_old * d_F.t() + d_Q;
// Measurement update
arma::vec z = {d_code_error_disc_chips, d_carr_phase_error_disc_hz * TWO_PI};
arma::mat K = d_P_new_old * d_H.t() * arma::inv(d_H * d_P_new_old * d_H.t() + d_R); // Kalman gain
d_x_new_new = d_x_new_old + K * z;
d_P_new_new = (arma::eye(4, 4) - K * d_H) * d_P_new_old;
// new code phase estimation
d_code_error_kf_chips = d_x_new_new(0);
d_x_new_new(0) = 0; // reset error estimation because the NCO corrects the code phase
// new carrier phase estimation
d_carrier_phase_kf_rad = d_x_new_new(1);
// New carrier Doppler frequency estimation
d_carrier_doppler_kf_hz = d_x_new_new(2);
// d_carr_freq_error_hz = fll_four_quadrant_atan(d_P_accu_old, d_P_accu, 0, d_current_correlation_time_s) / TWO_PI;
// d_x_new_new(2) = d_x_new_new(2) + fll_four_quadrant_atan(d_P_accu_old, d_P_accu, 0, d_current_correlation_time_s) / TWO_PI;
d_P_accu_old = d_P_accu;
d_carrier_doppler_rate_kf_hz_s = d_x_new_new(3);
// New code Doppler frequency estimation
d_code_freq_kf_chips_s = d_code_chip_rate + d_carrier_doppler_kf_hz * d_code_chip_rate / d_signal_carrier_freq;
// d_x_new_new(4) = 0;
// Experimental: detect Carrier Doppler vs. Code Doppler incoherence and correct the Carrier Doppler
// if (d_trk_parameters.enable_doppler_correction == true)
// {
// if (d_pull_in_transitory == false and d_corrected_doppler == false)
// {
// todo: algorithm here...
// }
// }
// correct code and carrier phase
d_rem_code_phase_samples += d_trk_parameters.fs_in * d_code_error_kf_chips / d_code_freq_kf_chips_s;
d_rem_carr_phase_rad = d_carrier_phase_kf_rad;
// prepare data for next KF epoch
d_x_old_old = d_x_new_new;
d_P_old_old = d_P_new_new;
}
void kf_tracking::check_carrier_phase_coherent_initialization()
{
if (d_acc_carrier_phase_initialized == false)
{
d_acc_carrier_phase_rad = -d_rem_carr_phase_rad;
d_acc_carrier_phase_initialized = true;
}
}
void kf_tracking::clear_tracking_vars()
{
std::fill_n(d_correlator_outs.begin(), d_n_correlator_taps, gr_complex(0.0, 0.0));
if (d_trk_parameters.track_pilot)
{
d_Prompt_Data[0] = gr_complex(0.0, 0.0);
d_P_data_accu = gr_complex(0.0, 0.0);
}
d_P_accu_old = gr_complex(0.0, 0.0);
d_current_symbol = 0;
d_current_data_symbol = 0;
d_Prompt_circular_buffer.clear();
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();
}
// todo: IT DOES NOT WORK WHEN NO KF IS RUNNING (extended correlation epochs!!)
void kf_tracking::update_tracking_vars()
{
d_T_chip_seconds = 1.0 / d_code_freq_kf_chips_s;
d_T_prn_seconds = d_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
d_T_prn_samples = d_T_prn_seconds * d_trk_parameters.fs_in;
d_K_blk_samples = d_T_prn_samples + d_rem_code_phase_samples;
d_current_prn_length_samples = static_cast<int32_t>(std::floor(d_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 = TWO_PI * d_carrier_doppler_kf_hz / d_trk_parameters.fs_in;
// d_rem_carr_phase_rad = d_carrier_phase_kf_rad;
// carrier phase rate step (NCO phase increment rate per sample) [rads/sample^2]
if (d_trk_parameters.high_dyn)
{
// d_carrier_phase_rate_step_rad = TWO_PI * d_carrier_doppler_rate_kf_hz_s / d_trk_parameters.fs_in;
// d_carrier_doppler_rate_kf_hz_s = d_carrier_phase_rate_step_rad * d_trk_parameters.fs_in / TWO_PI;
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 < d_trk_parameters.smoother_length; k++)
{
tmp_cp1 += d_carr_ph_history[k].first;
tmp_cp2 += d_carr_ph_history[d_trk_parameters.smoother_length * 2 - k - 1].first;
tmp_samples += d_carr_ph_history[d_trk_parameters.smoother_length * 2 - k - 1].second;
}
tmp_cp1 /= static_cast<double>(d_trk_parameters.smoother_length);
tmp_cp2 /= static_cast<double>(d_trk_parameters.smoother_length);
d_carrier_phase_rate_step_rad = (tmp_cp2 - tmp_cp1) / tmp_samples;
d_x_old_old(3) = d_carrier_phase_rate_step_rad * d_trk_parameters.fs_in / TWO_PI;
}
}
// remnant carrier phase to prevent overflow in the code NCO
auto remnant_carrier_phase = 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 += remnant_carrier_phase;
d_rem_carr_phase_rad = fmod(d_rem_carr_phase_rad, TWO_PI);
d_acc_carrier_phase_rad -= remnant_carrier_phase;
// ################### DLL COMMANDS #################################################
// code phase step (Code resampler phase increment per sample) [chips/sample]
d_code_phase_step_chips = d_code_freq_kf_chips_s / d_trk_parameters.fs_in;
// todo: extend kf to estimate code rate
if (d_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 < d_trk_parameters.smoother_length; k++)
{
tmp_cp1 += d_code_ph_history[k].first;
tmp_cp2 += d_code_ph_history[d_trk_parameters.smoother_length * 2 - k - 1].first;
tmp_samples += d_code_ph_history[d_trk_parameters.smoother_length * 2 - k - 1].second;
}
tmp_cp1 /= static_cast<double>(d_trk_parameters.smoother_length);
tmp_cp2 /= static_cast<double>(d_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 = d_K_blk_samples - static_cast<double>(d_current_prn_length_samples); // rounding error < 1 sample
d_rem_code_phase_chips = d_code_freq_kf_chips_s * d_rem_code_phase_samples / d_trk_parameters.fs_in;
}
void kf_tracking::save_correlation_results()
{
if (d_secondary)
{
if (d_secondary_code_string[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;
}
// data secondary code roll-up
if (d_symbols_per_bit > 1)
{
if (d_data_secondary_code_length > 0)
{
if (d_trk_parameters.track_pilot)
{
if (d_data_secondary_code_string[d_current_data_symbol] == '0')
{
d_P_data_accu += d_Prompt_Data[0];
}
else
{
d_P_data_accu -= d_Prompt_Data[0];
}
}
else
{
if (d_data_secondary_code_string[d_current_data_symbol] == '0')
{
d_P_data_accu += *d_Prompt;
}
else
{
d_P_data_accu -= *d_Prompt;
}
}
d_current_data_symbol++;
// data secondary code roll-up
d_current_data_symbol %= d_data_secondary_code_length;
}
else
{
if (d_trk_parameters.track_pilot)
{
d_P_data_accu += d_Prompt_Data[0];
}
else
{
d_P_data_accu += *d_Prompt;
// std::cout << "s[" << d_current_data_symbol << "]=" << (int)((*d_Prompt).real() > 0) << '\n';
}
d_current_data_symbol++;
d_current_data_symbol %= d_symbols_per_bit;
}
}
else
{
if (d_trk_parameters.track_pilot)
{
d_P_data_accu = d_Prompt_Data[0];
}
else
{
d_P_data_accu = *d_Prompt;
}
}
if (d_trk_parameters.track_pilot)
{
// If tracking pilot, disable Costas loop
d_cloop = false;
}
else
{
d_cloop = true;
}
}
void kf_tracking::log_data()
{
if (d_dump)
{
// Dump results to file
float prompt_I;
float prompt_Q;
float tmp_VE;
float tmp_E;
float tmp_P;
float tmp_L;
float tmp_VL;
float tmp_float;
double tmp_double;
uint64_t tmp_long_int;
if (d_trk_parameters.track_pilot)
{
prompt_I = d_Prompt_Data.data()->real();
prompt_Q = d_Prompt_Data.data()->imag();
}
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);
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 = static_cast<float>(d_acc_carrier_phase_rad);
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// carrier and code frequency
tmp_float = static_cast<float>(d_carrier_doppler_kf_hz);
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// carrier phase rate [Hz/s]
tmp_float = static_cast<float>(d_carrier_doppler_rate_kf_hz_s);
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
tmp_float = static_cast<float>(d_code_freq_kf_chips_s);
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// code phase rate [chips/s^2]
tmp_float = static_cast<float>(d_code_phase_rate_step_chips * d_trk_parameters.fs_in * d_trk_parameters.fs_in);
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// Carrier estimation
tmp_float = static_cast<float>(d_carr_phase_error_disc_hz);
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
tmp_float = static_cast<float>(d_x_new_new(2));
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// code estimation
tmp_float = static_cast<float>(d_code_error_disc_chips);
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
tmp_float = static_cast<float>(d_code_error_kf_chips);
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// CN0 and carrier lock test
tmp_float = static_cast<float>(d_CN0_SNV_dB_Hz);
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
tmp_float = static_cast<float>(d_carrier_lock_test);
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// AUX vars (for debug purposes)
tmp_float = static_cast<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::ofstream::failure &e)
{
LOG(WARNING) << "Exception writing trk dump file " << e.what();
}
}
}
int32_t kf_tracking::save_matfile() const
{
// READ DUMP FILE
std::ifstream::pos_type size;
const int32_t number_of_double_vars = 1;
const int32_t number_of_float_vars = 19;
const 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_ << '\n';
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() << '\n';
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 = std::vector<float>(num_epoch);
auto abs_E = std::vector<float>(num_epoch);
auto abs_P = std::vector<float>(num_epoch);
auto abs_L = std::vector<float>(num_epoch);
auto abs_VL = std::vector<float>(num_epoch);
auto Prompt_I = std::vector<float>(num_epoch);
auto Prompt_Q = std::vector<float>(num_epoch);
auto PRN_start_sample_count = std::vector<uint64_t>(num_epoch);
auto acc_carrier_phase_rad = std::vector<float>(num_epoch);
auto carrier_doppler_hz = std::vector<float>(num_epoch);
auto carrier_doppler_rate_hz = std::vector<float>(num_epoch);
auto code_freq_chips = std::vector<float>(num_epoch);
auto code_freq_rate_chips = std::vector<float>(num_epoch);
auto carr_error_hz = std::vector<float>(num_epoch);
auto carr_error_filt_hz = std::vector<float>(num_epoch);
auto code_error_chips = std::vector<float>(num_epoch);
auto code_error_filt_chips = std::vector<float>(num_epoch);
auto CN0_SNV_dB_Hz = std::vector<float>(num_epoch);
auto carrier_lock_test = std::vector<float>(num_epoch);
auto aux1 = std::vector<float>(num_epoch);
auto aux2 = std::vector<double>(num_epoch);
auto PRN = std::vector<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() << '\n';
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)
{
std::array<size_t, 2> dims{1, static_cast<size_t>(num_epoch)};
matvar = Mat_VarCreate("abs_VE", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims.data(), abs_VE.data(), 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.data(), abs_E.data(), 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.data(), abs_P.data(), 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.data(), abs_L.data(), 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.data(), abs_VL.data(), 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.data(), Prompt_I.data(), 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.data(), Prompt_Q.data(), 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.data(), PRN_start_sample_count.data(), 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.data(), acc_carrier_phase_rad.data(), 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.data(), carrier_doppler_hz.data(), 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.data(), carrier_doppler_rate_hz.data(), 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.data(), code_freq_chips.data(), 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.data(), code_freq_rate_chips.data(), 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.data(), carr_error_hz.data(), 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.data(), carr_error_filt_hz.data(), 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.data(), code_error_chips.data(), 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.data(), code_error_filt_chips.data(), 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.data(), CN0_SNV_dB_Hz.data(), 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.data(), carrier_lock_test.data(), 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.data(), aux1.data(), 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.data(), aux2.data(), 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.data(), PRN.data(), 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
}
Mat_Close(matfp);
return 0;
}
void kf_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
{
d_dump_file.exceptions(std::ofstream::failbit | std::ofstream::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::ofstream::failure &e)
{
LOG(WARNING) << "channel " << d_channel << " Exception opening trk dump file " << e.what();
}
}
}
}
void kf_tracking::set_gnss_synchro(Gnss_Synchro *p_gnss_synchro)
{
gr::thread::scoped_lock l(d_setlock);
d_acquisition_gnss_synchro = p_gnss_synchro;
}
void kf_tracking::stop_tracking()
{
gr::thread::scoped_lock l(d_setlock);
d_state = 0;
}
int kf_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();
current_synchro_data.Flag_valid_symbol_output = false;
if (d_pull_in_transitory == true)
{
if (d_trk_parameters.pull_in_time_s < (d_sample_counter - d_acq_sample_stamp) / static_cast<int>(d_trk_parameters.fs_in))
{
d_pull_in_transitory = false;
d_carrier_lock_fail_counter = 0;
d_code_lock_fail_counter = 0;
}
}
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)
const int64_t acq_trk_diff_samples = static_cast<int64_t>(d_sample_counter) - static_cast<int64_t>(d_acq_sample_stamp);
const double acq_trk_diff_seconds = static_cast<double>(acq_trk_diff_samples) / d_trk_parameters.fs_in;
const double delta_trk_to_acq_prn_start_samples = static_cast<double>(acq_trk_diff_samples) - d_acq_code_phase_samples;
d_code_freq_kf_chips_s = d_code_chip_rate;
d_code_phase_step_chips = d_code_freq_kf_chips_s / d_trk_parameters.fs_in;
d_code_phase_rate_step_chips = 0.0;
const double T_chip_mod_seconds = 1.0 / d_code_freq_kf_chips_s;
const double T_prn_mod_seconds = T_chip_mod_seconds * static_cast<double>(d_code_length_chips);
const double T_prn_mod_samples = T_prn_mod_seconds * d_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);
const 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
d_cn0_smoother.reset();
d_carrier_lock_test_smoother.reset();
init_kf(0.0, d_carrier_doppler_kf_hz);
LOG(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_kf_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;
d_trk_parameters.spc = d_trk_parameters.early_late_space_chips;
// if (std::string(d_trk_parameters.signal) == "E1")
// {
// d_trk_parameters.slope = -CalculateSlopeAbs(&SinBocCorrelationFunction<1, 1>, d_trk_parameters.spc);
// d_trk_parameters.y_intercept = GetYInterceptAbs(&SinBocCorrelationFunction<1, 1>, d_trk_parameters.spc);
// }
// fail-safe: check if the secondary code or bit synchronization has not succeeded in a limited time period
if (d_trk_parameters.bit_synchronization_time_limit_s < (d_sample_counter - d_acq_sample_stamp) / static_cast<int>(d_trk_parameters.fs_in))
{
d_carrier_lock_fail_counter = 300000; // force loss-of-lock condition
LOG(INFO) << d_systemName << " " << d_signal_pretty_name << " tracking synchronization time limit reached in channel " << d_channel
<< " for satellite " << Gnss_Satellite(d_systemName, d_acquisition_gnss_synchro->PRN) << '\n';
}
// 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_Kf();
update_tracking_vars();
// enable write dump file this cycle (valid DLL/PLL cycle)
log_data();
if (!d_pull_in_transitory)
{
if (d_secondary)
{
// ####### SECONDARY CODE LOCK #####
d_Prompt_circular_buffer.push_back(*d_Prompt);
if (d_Prompt_circular_buffer.size() == d_secondary_code_length)
{
next_state = acquire_secondary();
if (next_state)
{
LOG(INFO) << d_systemName << " " << d_signal_pretty_name << " secondary code locked in channel " << d_channel
<< " for satellite " << Gnss_Satellite(d_systemName, d_acquisition_gnss_synchro->PRN) << '\n';
std::cout << d_systemName << " " << d_signal_pretty_name << " secondary code locked in channel " << d_channel
<< " for satellite " << Gnss_Satellite(d_systemName, d_acquisition_gnss_synchro->PRN) << '\n';
}
}
}
else if (d_symbols_per_bit > 1) // Signal does not have secondary code. Search a bit transition by sign change
{
// ******* preamble correlation ********
d_Prompt_circular_buffer.push_back(*d_Prompt);
if (d_Prompt_circular_buffer.size() == d_secondary_code_length)
{
next_state = acquire_secondary();
if (next_state)
{
LOG(INFO) << d_systemName << " " << d_signal_pretty_name << " tracking bit synchronization locked in channel " << d_channel
<< " for satellite " << Gnss_Satellite(d_systemName, d_acquisition_gnss_synchro->PRN) << '\n';
std::cout << d_systemName << " " << d_signal_pretty_name << " tracking bit synchronization locked in channel " << d_channel
<< " for satellite " << Gnss_Satellite(d_systemName, d_acquisition_gnss_synchro->PRN) << '\n';
}
}
}
else
{
next_state = true;
}
}
else
{
next_state = false; // keep in state 2 during pull-in transitory
}
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_P_data_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_Prompt_circular_buffer.clear();
d_current_symbol = 0;
d_current_data_symbol = 0;
if (d_enable_extended_integration)
{
// UPDATE INTEGRATION TIME
d_extend_correlation_symbols_count = 0;
d_current_correlation_time_s = static_cast<float>(d_trk_parameters.extend_correlation_symbols) * static_cast<float>(d_code_period);
d_state = 3; // next state is the extended correlator integrator
LOG(INFO) << "Enabled " << d_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(d_systemName, d_acquisition_gnss_synchro->PRN);
std::cout << "Enabled " << d_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(d_systemName, d_acquisition_gnss_synchro->PRN) << '\n';
// Set narrow taps delay values [chips]
update_kf_narrow_integration_time();
if (d_veml)
{
d_local_code_shift_chips[0] = -d_trk_parameters.very_early_late_space_narrow_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[1] = -d_trk_parameters.early_late_space_narrow_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[3] = d_trk_parameters.early_late_space_narrow_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[4] = d_trk_parameters.very_early_late_space_narrow_chips * static_cast<float>(d_code_samples_per_chip);
d_trk_parameters.spc = d_trk_parameters.early_late_space_narrow_chips;
// if (std::string(d_trk_parameters.signal) == "E1")
// {
// d_trk_parameters.slope = -CalculateSlopeAbs(&SinBocCorrelationFunction<1, 1>, d_trk_parameters.spc);
// d_trk_parameters.y_intercept = GetYInterceptAbs(&SinBocCorrelationFunction<1, 1>, d_trk_parameters.spc);
// }
}
else
{
d_local_code_shift_chips[0] = -d_trk_parameters.early_late_space_narrow_chips * static_cast<float>(d_code_samples_per_chip);
d_local_code_shift_chips[2] = d_trk_parameters.early_late_space_narrow_chips * static_cast<float>(d_code_samples_per_chip);
d_trk_parameters.spc = d_trk_parameters.early_late_space_narrow_chips;
}
}
else
{
d_state = 4;
}
}
}
break;
}
case 3: // coherent integration (correlation time extension)
{
// perform a correlation step
do_correlation_step(in);
save_correlation_results();
// run_Kf();
update_tracking_vars(); // ?
if (d_current_data_symbol == 0)
{
log_data();
// ########### Output the tracking results to Telemetry block ##########
// Fill the acquisition data
current_synchro_data = *d_acquisition_gnss_synchro;
if (d_interchange_iq)
{
current_synchro_data.Prompt_I = static_cast<double>(d_P_data_accu.imag());
current_synchro_data.Prompt_Q = static_cast<double>(d_P_data_accu.real());
}
else
{
current_synchro_data.Prompt_I = static_cast<double>(d_P_data_accu.real());
current_synchro_data.Prompt_Q = static_cast<double>(d_P_data_accu.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_kf_hz;
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
current_synchro_data.correlation_length_ms = d_correlation_length_ms;
current_synchro_data.Flag_valid_symbol_output = true;
d_P_data_accu = gr_complex(0.0, 0.0);
}
d_extend_correlation_symbols_count++;
if (d_extend_correlation_symbols_count == (d_trk_parameters.extend_correlation_symbols - 1))
{
d_extend_correlation_symbols_count = 0;
d_state = 4;
}
break;
}
case 4: // narrow tracking
{
// 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>(d_trk_parameters.extend_correlation_symbols)))
{
clear_tracking_vars();
d_state = 0; // loss-of-lock detected
}
else
{
update_kf_cn0(d_CN0_SNV_dB_Hz);
run_Kf();
update_tracking_vars();
check_carrier_phase_coherent_initialization();
if (d_current_data_symbol == 0)
{
// enable write dump file this cycle (valid DLL/PLL cycle)
log_data();
// ########### Output the tracking results to Telemetry block ##########
// Fill the acquisition data
current_synchro_data = *d_acquisition_gnss_synchro;
if (d_interchange_iq)
{
current_synchro_data.Prompt_I = static_cast<double>(d_P_data_accu.imag());
current_synchro_data.Prompt_Q = static_cast<double>(d_P_data_accu.real());
}
else
{
current_synchro_data.Prompt_I = static_cast<double>(d_P_data_accu.real());
current_synchro_data.Prompt_Q = static_cast<double>(d_P_data_accu.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_kf_hz;
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
current_synchro_data.correlation_length_ms = d_correlation_length_ms;
current_synchro_data.Flag_valid_symbol_output = true;
d_P_data_accu = gr_complex(0.0, 0.0);
}
// 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>(d_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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