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https://github.com/gnss-sdr/gnss-sdr
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Add Glonass C Aid track blocks
This commit is contained in:
Gastd
parent
c8488eff56
commit
bbec0acf28
@ -36,6 +36,8 @@ set(TRACKING_GR_BLOCKS_SOURCES
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gps_l1_ca_dll_pll_c_aid_tracking_cc.cc
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gps_l1_ca_dll_pll_c_aid_tracking_sc.cc
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glonass_l1_ca_dll_pll_tracking_cc.cc
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glonass_l1_ca_dll_pll_c_aid_tracking_cc.cc
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glonass_l1_ca_dll_pll_c_aid_tracking_sc.cc
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${OPT_TRACKING_BLOCKS}
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)
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@ -0,0 +1,646 @@
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#include "glonass_l1_ca_dll_pll_c_aid_tracking_cc.h"
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#include <cmath>
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#include <iostream>
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#include <memory>
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#include <sstream>
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#include <boost/lexical_cast.hpp>
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#include <boost/bind.hpp>
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#include <gnuradio/io_signature.h>
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#include <pmt/pmt.h>
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#include <volk_gnsssdr/volk_gnsssdr.h>
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#include <glog/logging.h>
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#include "glonass_l1_signal_processing.h"
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#include "tracking_discriminators.h"
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#include "lock_detectors.h"
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#include "Glonass_L1_CA.h"
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#include "control_message_factory.h"
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/*!
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* \todo Include in definition header file
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*/
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#define CN0_ESTIMATION_SAMPLES 20
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#define MINIMUM_VALID_CN0 25
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#define MAXIMUM_LOCK_FAIL_COUNTER 50
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#define CARRIER_LOCK_THRESHOLD 0.85
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using google::LogMessage;
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glonass_l1_ca_dll_pll_c_aid_tracking_cc_sptr
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glonass_l1_ca_dll_pll_c_aid_make_tracking_cc(
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long if_freq,
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long fs_in,
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unsigned int vector_length,
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bool dump,
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std::string dump_filename,
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float pll_bw_hz,
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float dll_bw_hz,
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float pll_bw_narrow_hz,
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float dll_bw_narrow_hz,
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int extend_correlation_ms,
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float early_late_space_chips)
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{
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return glonass_l1_ca_dll_pll_c_aid_tracking_cc_sptr(new glonass_l1_ca_dll_pll_c_aid_tracking_cc(if_freq,
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fs_in, vector_length, dump, dump_filename, pll_bw_hz, dll_bw_hz,pll_bw_narrow_hz, dll_bw_narrow_hz, extend_correlation_ms, early_late_space_chips));
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}
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void glonass_l1_ca_dll_pll_c_aid_tracking_cc::forecast (int noutput_items,
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gr_vector_int &ninput_items_required)
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{
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if (noutput_items != 0)
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{
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ninput_items_required[0] = static_cast<int>(d_vector_length) * 2; //set the required available samples in each call
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}
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}
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void glonass_l1_ca_dll_pll_c_aid_tracking_cc::msg_handler_preamble_index(pmt::pmt_t msg)
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{
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//pmt::print(msg);
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DLOG(INFO) << "Extended correlation enabled for Tracking CH " << d_channel << ": Satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN);
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if (d_enable_extended_integration == false) //avoid re-setting preamble indicator
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{
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d_preamble_timestamp_s = pmt::to_double(msg);
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d_enable_extended_integration = true;
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d_preamble_synchronized = false;
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}
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}
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glonass_l1_ca_dll_pll_c_aid_tracking_cc::glonass_l1_ca_dll_pll_c_aid_tracking_cc(
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long if_freq,
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long fs_in,
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unsigned int vector_length,
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bool dump,
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std::string dump_filename,
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float pll_bw_hz,
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float dll_bw_hz,
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float pll_bw_narrow_hz,
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float dll_bw_narrow_hz,
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int extend_correlation_ms,
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float early_late_space_chips) :
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gr::block("glonass_l1_ca_dll_pll_c_aid_tracking_cc", gr::io_signature::make(1, 1, sizeof(gr_complex)),
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gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)))
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{
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// Telemetry bit synchronization message port input
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this->message_port_register_in(pmt::mp("preamble_timestamp_s"));
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this->set_msg_handler(pmt::mp("preamble_timestamp_s"),
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boost::bind(&glonass_l1_ca_dll_pll_c_aid_tracking_cc::msg_handler_preamble_index, this, _1));
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this->message_port_register_out(pmt::mp("events"));
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// initialize internal vars
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d_dump = dump;
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d_if_freq = if_freq;
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d_fs_in = fs_in;
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d_vector_length = vector_length;
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d_dump_filename = dump_filename;
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d_correlation_length_samples = static_cast<int>(d_vector_length);
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// Initialize tracking ==========================================
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d_pll_bw_hz = pll_bw_hz;
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d_dll_bw_hz = dll_bw_hz;
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d_pll_bw_narrow_hz = pll_bw_narrow_hz;
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d_dll_bw_narrow_hz = dll_bw_narrow_hz;
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d_extend_correlation_ms = extend_correlation_ms;
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d_code_loop_filter.set_DLL_BW(d_dll_bw_hz);
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d_carrier_loop_filter.set_params(10.0, d_pll_bw_hz, 2);
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// --- DLL variables --------------------------------------------------------
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d_early_late_spc_chips = early_late_space_chips; // Define early-late offset (in chips)
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// Initialization of local code replica
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// Get space for a vector with the C/A code replica sampled 1x/chip
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d_ca_code = static_cast<gr_complex*>(volk_gnsssdr_malloc(static_cast<int>(GLONASS_L1_CA_CODE_LENGTH_CHIPS) * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
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// correlator outputs (scalar)
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d_n_correlator_taps = 3; // Early, Prompt, and Late
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d_correlator_outs = static_cast<gr_complex*>(volk_gnsssdr_malloc(d_n_correlator_taps*sizeof(gr_complex), volk_gnsssdr_get_alignment()));
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for (int n = 0; n < d_n_correlator_taps; n++)
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{
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d_correlator_outs[n] = gr_complex(0,0);
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}
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d_local_code_shift_chips = static_cast<float*>(volk_gnsssdr_malloc(d_n_correlator_taps*sizeof(float), volk_gnsssdr_get_alignment()));
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// Set TAPs delay values [chips]
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d_local_code_shift_chips[0] = - d_early_late_spc_chips;
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d_local_code_shift_chips[1] = 0.0;
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d_local_code_shift_chips[2] = d_early_late_spc_chips;
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multicorrelator_cpu.init(2 * d_correlation_length_samples, d_n_correlator_taps);
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//--- Perform initializations ------------------------------
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// define initial code frequency basis of NCO
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d_code_freq_chips = GLONASS_L1_CA_CODE_RATE_HZ;
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// define residual code phase (in chips)
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d_rem_code_phase_samples = 0.0;
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// define residual carrier phase
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d_rem_carrier_phase_rad = 0.0;
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// sample synchronization
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d_sample_counter = 0; //(from trk to tlm)
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d_acq_sample_stamp = 0;
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d_enable_tracking = false;
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d_pull_in = false;
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// CN0 estimation and lock detector buffers
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d_cn0_estimation_counter = 0;
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d_Prompt_buffer = new gr_complex[CN0_ESTIMATION_SAMPLES];
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d_carrier_lock_test = 1;
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d_CN0_SNV_dB_Hz = 0;
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d_carrier_lock_fail_counter = 0;
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d_carrier_lock_threshold = CARRIER_LOCK_THRESHOLD;
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systemName["R"] = std::string("Glonass");
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set_relative_rate(1.0 / static_cast<double>(d_vector_length));
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d_acquisition_gnss_synchro = 0;
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d_channel = 0;
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d_acq_code_phase_samples = 0.0;
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d_acq_carrier_doppler_hz = 0.0;
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d_carrier_doppler_hz = 0.0;
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d_code_error_filt_chips_Ti = 0.0;
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d_acc_carrier_phase_cycles = 0.0;
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d_code_phase_samples = 0.0;
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d_pll_to_dll_assist_secs_Ti = 0.0;
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d_rem_code_phase_chips = 0.0;
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d_code_phase_step_chips = 0.0;
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d_carrier_phase_step_rad = 0.0;
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d_enable_extended_integration = false;
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d_preamble_synchronized = false;
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d_rem_code_phase_integer_samples = 0;
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d_code_error_chips_Ti = 0.0;
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d_code_error_filt_chips_s = 0.0;
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d_carr_phase_error_secs_Ti = 0.0;
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d_preamble_timestamp_s = 0.0;
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//set_min_output_buffer((long int)300);
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}
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void glonass_l1_ca_dll_pll_c_aid_tracking_cc::start_tracking()
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{
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/*
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* correct the code phase according to the delay between acq and trk
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*/
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d_acq_code_phase_samples = d_acquisition_gnss_synchro->Acq_delay_samples;
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d_acq_carrier_doppler_hz = d_acquisition_gnss_synchro->Acq_doppler_hz;
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d_acq_sample_stamp = d_acquisition_gnss_synchro->Acq_samplestamp_samples;
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long int acq_trk_diff_samples;
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double acq_trk_diff_seconds;
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acq_trk_diff_samples = static_cast<long int>(d_sample_counter) - static_cast<long int>(d_acq_sample_stamp);//-d_vector_length;
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DLOG(INFO) << "Number of samples between Acquisition and Tracking =" << acq_trk_diff_samples;
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acq_trk_diff_seconds = static_cast<double>(acq_trk_diff_samples) / static_cast<double>(d_fs_in);
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// Doppler effect
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// Fd=(C/(C+Vr))*F
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d_glonass_freq_ch = GLONASS_L1_FREQ_HZ + (GLONASS_L1_FREQ_HZ * GLONASS_PRN.at(d_acquisition_gnss_synchro->PRN));
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double radial_velocity = (d_glonass_freq_ch + d_acq_carrier_doppler_hz) / d_glonass_freq_ch;
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// new chip and prn sequence periods based on acq Doppler
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double T_chip_mod_seconds;
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double T_prn_mod_seconds;
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double T_prn_mod_samples;
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d_code_freq_chips = radial_velocity * GLONASS_L1_CA_CODE_RATE_HZ;
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d_code_phase_step_chips = static_cast<double>(d_code_freq_chips) / static_cast<double>(d_fs_in);
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T_chip_mod_seconds = 1.0 / d_code_freq_chips;
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T_prn_mod_seconds = T_chip_mod_seconds * GLONASS_L1_CA_CODE_LENGTH_CHIPS;
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T_prn_mod_samples = T_prn_mod_seconds * static_cast<double>(d_fs_in);
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d_correlation_length_samples = round(T_prn_mod_samples);
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double T_prn_true_seconds = GLONASS_L1_CA_CODE_LENGTH_CHIPS / GLONASS_L1_CA_CODE_RATE_HZ;
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double T_prn_true_samples = T_prn_true_seconds * static_cast<double>(d_fs_in);
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double T_prn_diff_seconds = T_prn_true_seconds - T_prn_mod_seconds;
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double N_prn_diff = acq_trk_diff_seconds / T_prn_true_seconds;
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double corrected_acq_phase_samples, delay_correction_samples;
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corrected_acq_phase_samples = fmod((d_acq_code_phase_samples + T_prn_diff_seconds * N_prn_diff * static_cast<double>(d_fs_in)), T_prn_true_samples);
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if (corrected_acq_phase_samples < 0)
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{
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corrected_acq_phase_samples = T_prn_mod_samples + corrected_acq_phase_samples;
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}
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delay_correction_samples = d_acq_code_phase_samples - corrected_acq_phase_samples;
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d_acq_code_phase_samples = corrected_acq_phase_samples;
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d_carrier_doppler_hz = d_acq_carrier_doppler_hz;
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d_carrier_phase_step_rad = GLONASS_TWO_PI * d_carrier_doppler_hz / static_cast<double>(d_fs_in);
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// DLL/PLL filter initialization
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d_carrier_loop_filter.initialize(d_acq_carrier_doppler_hz); // The carrier loop filter implements the Doppler accumulator
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d_code_loop_filter.initialize(); // initialize the code filter
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// generate local reference ALWAYS starting at chip 1 (1 sample per chip)
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glonass_l1_ca_code_gen_complex(d_ca_code, 0);
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multicorrelator_cpu.set_local_code_and_taps(static_cast<int>(GLONASS_L1_CA_CODE_LENGTH_CHIPS), d_ca_code, d_local_code_shift_chips);
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for (int n = 0; n < d_n_correlator_taps; n++)
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{
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d_correlator_outs[n] = gr_complex(0,0);
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}
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d_carrier_lock_fail_counter = 0;
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d_rem_code_phase_samples = 0.0;
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d_rem_carrier_phase_rad = 0.0;
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d_rem_code_phase_chips = 0.0;
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d_acc_carrier_phase_cycles = 0.0;
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d_pll_to_dll_assist_secs_Ti = 0.0;
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d_code_phase_samples = d_acq_code_phase_samples;
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std::string sys_ = &d_acquisition_gnss_synchro->System;
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sys = sys_.substr(0,1);
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// DEBUG OUTPUT
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std::cout << "Tracking start on channel " << d_channel << " for satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << std::endl;
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LOG(INFO) << "Starting tracking of satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << " on channel " << d_channel;
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// enable tracking
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d_pull_in = true;
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d_enable_tracking = true;
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d_enable_extended_integration = true;
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d_preamble_synchronized = true;
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LOG(INFO) << "PULL-IN Doppler [Hz]=" << d_carrier_doppler_hz
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<< " Code Phase correction [samples]=" << delay_correction_samples
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<< " PULL-IN Code Phase [samples]=" << d_acq_code_phase_samples;
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}
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glonass_l1_ca_dll_pll_c_aid_tracking_cc::~glonass_l1_ca_dll_pll_c_aid_tracking_cc()
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{
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d_dump_file.close();
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volk_gnsssdr_free(d_local_code_shift_chips);
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volk_gnsssdr_free(d_correlator_outs);
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volk_gnsssdr_free(d_ca_code);
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delete[] d_Prompt_buffer;
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multicorrelator_cpu.free();
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}
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int glonass_l1_ca_dll_pll_c_aid_tracking_cc::general_work (int noutput_items __attribute__((unused)), gr_vector_int &ninput_items __attribute__((unused)),
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gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)
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{
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// Block input data and block output stream pointers
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const gr_complex* in = (gr_complex*) input_items[0]; //PRN start block alignment
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Gnss_Synchro **out = (Gnss_Synchro **) &output_items[0];
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// GNSS_SYNCHRO OBJECT to interchange data between tracking->telemetry_decoder
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Gnss_Synchro current_synchro_data = Gnss_Synchro();
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// process vars
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double code_error_filt_secs_Ti = 0.0;
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double CURRENT_INTEGRATION_TIME_S = 0.0;
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double CORRECTED_INTEGRATION_TIME_S = 0.0;
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if (d_enable_tracking == true)
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{
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// Fill the acquisition data
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current_synchro_data = *d_acquisition_gnss_synchro;
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// Receiver signal alignment
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if (d_pull_in == true)
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{
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int samples_offset;
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double acq_trk_shif_correction_samples;
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int acq_to_trk_delay_samples;
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acq_to_trk_delay_samples = d_sample_counter - d_acq_sample_stamp;
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acq_trk_shif_correction_samples = d_correlation_length_samples - fmod(static_cast<double>(acq_to_trk_delay_samples), static_cast<double>(d_correlation_length_samples));
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samples_offset = round(d_acq_code_phase_samples + acq_trk_shif_correction_samples);
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current_synchro_data.Tracking_sample_counter = d_sample_counter + samples_offset;
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d_sample_counter += samples_offset; // count for the processed samples
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d_pull_in = false;
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d_acc_carrier_phase_cycles -= d_carrier_phase_step_rad * samples_offset / GLONASS_TWO_PI;
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current_synchro_data.Carrier_phase_rads = d_acc_carrier_phase_cycles * GLONASS_TWO_PI;
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current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;
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current_synchro_data.fs=d_fs_in;
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*out[0] = current_synchro_data;
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consume_each(samples_offset); // shift input to perform alignment with local replica
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return 1;
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}
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// ################# CARRIER WIPEOFF AND CORRELATORS ##############################
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// perform carrier wipe-off and compute Early, Prompt and Late correlation
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multicorrelator_cpu.set_input_output_vectors(d_correlator_outs,in);
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multicorrelator_cpu.Carrier_wipeoff_multicorrelator_resampler(d_rem_carrier_phase_rad,
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d_carrier_phase_step_rad,
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d_rem_code_phase_chips,
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d_code_phase_step_chips,
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d_correlation_length_samples);
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// ####### coherent intergration extension
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// keep the last symbols
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d_E_history.push_back(d_correlator_outs[0]); // save early output
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d_P_history.push_back(d_correlator_outs[1]); // save prompt output
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d_L_history.push_back(d_correlator_outs[2]); // save late output
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if (static_cast<int>(d_P_history.size()) > d_extend_correlation_ms)
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{
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d_E_history.pop_front();
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d_P_history.pop_front();
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d_L_history.pop_front();
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}
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bool enable_dll_pll;
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if (d_enable_extended_integration == true)
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{
|
||||
long int symbol_diff = round(1000.0 * ((static_cast<double>(d_sample_counter) + d_rem_code_phase_samples) / static_cast<double>(d_fs_in) - d_preamble_timestamp_s));
|
||||
if (symbol_diff > 0 and symbol_diff % d_extend_correlation_ms == 0)
|
||||
{
|
||||
// compute coherent integration and enable tracking loop
|
||||
// perform coherent integration using correlator output history
|
||||
// std::cout<<"##### RESET COHERENT INTEGRATION ####"<<std::endl;
|
||||
d_correlator_outs[0] = gr_complex(0.0,0.0);
|
||||
d_correlator_outs[1] = gr_complex(0.0,0.0);
|
||||
d_correlator_outs[2] = gr_complex(0.0,0.0);
|
||||
for (int n = 0; n < d_extend_correlation_ms; n++)
|
||||
{
|
||||
d_correlator_outs[0] += d_E_history.at(n);
|
||||
d_correlator_outs[1] += d_P_history.at(n);
|
||||
d_correlator_outs[2] += d_L_history.at(n);
|
||||
}
|
||||
|
||||
if (d_preamble_synchronized == false)
|
||||
{
|
||||
d_code_loop_filter.set_DLL_BW(d_dll_bw_narrow_hz);
|
||||
d_carrier_loop_filter.set_params(10.0, d_pll_bw_narrow_hz,2);
|
||||
d_preamble_synchronized = true;
|
||||
std::cout << "Enabled " << d_extend_correlation_ms << " [ms] extended correlator for CH "<< d_channel << " : Satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN)
|
||||
<< " pll_bw = " << d_pll_bw_hz << " [Hz], pll_narrow_bw = " << d_pll_bw_narrow_hz << " [Hz]" << std::endl
|
||||
<< " dll_bw = " << d_dll_bw_hz << " [Hz], dll_narrow_bw = " << d_dll_bw_narrow_hz << " [Hz]" << std::endl;
|
||||
}
|
||||
// UPDATE INTEGRATION TIME
|
||||
CURRENT_INTEGRATION_TIME_S = static_cast<double>(d_extend_correlation_ms) * GLONASS_L1_CA_CODE_PERIOD;
|
||||
d_code_loop_filter.set_pdi(CURRENT_INTEGRATION_TIME_S);
|
||||
enable_dll_pll = true;
|
||||
}
|
||||
else
|
||||
{
|
||||
if(d_preamble_synchronized == true)
|
||||
{
|
||||
// continue extended coherent correlation
|
||||
// Compute the next buffer length based on the period of the PRN sequence and the code phase error estimation
|
||||
double T_chip_seconds = 1.0 / d_code_freq_chips;
|
||||
double T_prn_seconds = T_chip_seconds * GLONASS_L1_CA_CODE_LENGTH_CHIPS;
|
||||
double T_prn_samples = T_prn_seconds * static_cast<double>(d_fs_in);
|
||||
int K_prn_samples = round(T_prn_samples);
|
||||
double K_T_prn_error_samples = K_prn_samples - T_prn_samples;
|
||||
|
||||
d_rem_code_phase_samples = d_rem_code_phase_samples - K_T_prn_error_samples;
|
||||
d_rem_code_phase_integer_samples = round(d_rem_code_phase_samples); // round to a discrete number of samples
|
||||
d_correlation_length_samples = K_prn_samples + d_rem_code_phase_integer_samples;
|
||||
d_rem_code_phase_samples = d_rem_code_phase_samples - d_rem_code_phase_integer_samples;
|
||||
// code phase step (Code resampler phase increment per sample) [chips/sample]
|
||||
d_code_phase_step_chips = d_code_freq_chips / static_cast<double>(d_fs_in);
|
||||
// remnant code phase [chips]
|
||||
d_rem_code_phase_chips = d_rem_code_phase_samples * (d_code_freq_chips / static_cast<double>(d_fs_in));
|
||||
d_rem_carrier_phase_rad = fmod(d_rem_carrier_phase_rad + d_carrier_phase_step_rad * static_cast<double>(d_correlation_length_samples), GLONASS_TWO_PI);
|
||||
|
||||
// UPDATE ACCUMULATED CARRIER PHASE
|
||||
CORRECTED_INTEGRATION_TIME_S = (static_cast<double>(d_correlation_length_samples) / static_cast<double>(d_fs_in));
|
||||
d_acc_carrier_phase_cycles -= d_carrier_phase_step_rad * d_correlation_length_samples / GLONASS_TWO_PI;
|
||||
|
||||
// disable tracking loop and inform telemetry decoder
|
||||
enable_dll_pll = false;
|
||||
}
|
||||
else
|
||||
{
|
||||
// perform basic (1ms) correlation
|
||||
// UPDATE INTEGRATION TIME
|
||||
CURRENT_INTEGRATION_TIME_S = static_cast<double>(d_correlation_length_samples) / static_cast<double>(d_fs_in);
|
||||
d_code_loop_filter.set_pdi(CURRENT_INTEGRATION_TIME_S);
|
||||
enable_dll_pll = true;
|
||||
}
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
// UPDATE INTEGRATION TIME
|
||||
CURRENT_INTEGRATION_TIME_S = static_cast<double>(d_correlation_length_samples) / static_cast<double>(d_fs_in);
|
||||
enable_dll_pll = true;
|
||||
}
|
||||
|
||||
if (enable_dll_pll == true)
|
||||
{
|
||||
// ################## PLL ##########################################################
|
||||
// Update PLL discriminator [rads/Ti -> Secs/Ti]
|
||||
d_carr_phase_error_secs_Ti = pll_cloop_two_quadrant_atan(d_correlator_outs[1]) / GLONASS_TWO_PI; // prompt output
|
||||
// Carrier discriminator filter
|
||||
// NOTICE: The carrier loop filter includes the Carrier Doppler accumulator, as described in Kaplan
|
||||
// Input [s/Ti] -> output [Hz]
|
||||
d_carrier_doppler_hz = d_carrier_loop_filter.get_carrier_error(0.0, d_carr_phase_error_secs_Ti, CURRENT_INTEGRATION_TIME_S);
|
||||
// PLL to DLL assistance [Secs/Ti]
|
||||
d_pll_to_dll_assist_secs_Ti = (d_carrier_doppler_hz * CURRENT_INTEGRATION_TIME_S) / d_glonass_freq_ch;
|
||||
// code Doppler frequency update
|
||||
d_code_freq_chips = GLONASS_L1_CA_CODE_RATE_HZ + ((d_carrier_doppler_hz * GLONASS_L1_CA_CODE_RATE_HZ) / d_glonass_freq_ch);
|
||||
|
||||
// ################## DLL ##########################################################
|
||||
// DLL discriminator
|
||||
d_code_error_chips_Ti = dll_nc_e_minus_l_normalized(d_correlator_outs[0], d_correlator_outs[2]); // [chips/Ti] //early and late
|
||||
// Code discriminator filter
|
||||
d_code_error_filt_chips_s = d_code_loop_filter.get_code_nco(d_code_error_chips_Ti); // input [chips/Ti] -> output [chips/second]
|
||||
d_code_error_filt_chips_Ti = d_code_error_filt_chips_s * CURRENT_INTEGRATION_TIME_S;
|
||||
code_error_filt_secs_Ti = d_code_error_filt_chips_Ti / d_code_freq_chips; // [s/Ti]
|
||||
|
||||
// ################## CARRIER AND CODE NCO BUFFER ALIGNEMENT #######################
|
||||
// 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
|
||||
double T_chip_seconds = 1.0 / d_code_freq_chips;
|
||||
double T_prn_seconds = T_chip_seconds * GLONASS_L1_CA_CODE_LENGTH_CHIPS;
|
||||
double T_prn_samples = T_prn_seconds * static_cast<double>(d_fs_in);
|
||||
double K_prn_samples = round(T_prn_samples);
|
||||
double K_T_prn_error_samples = K_prn_samples - T_prn_samples;
|
||||
|
||||
d_rem_code_phase_samples = d_rem_code_phase_samples - K_T_prn_error_samples + code_error_filt_secs_Ti * static_cast<double>(d_fs_in); //(code_error_filt_secs_Ti + d_pll_to_dll_assist_secs_Ti) * static_cast<double>(d_fs_in);
|
||||
d_rem_code_phase_integer_samples = round(d_rem_code_phase_samples); // round to a discrete number of samples
|
||||
d_correlation_length_samples = K_prn_samples + d_rem_code_phase_integer_samples;
|
||||
d_rem_code_phase_samples = d_rem_code_phase_samples - d_rem_code_phase_integer_samples;
|
||||
|
||||
//################### PLL COMMANDS #################################################
|
||||
//carrier phase step (NCO phase increment per sample) [rads/sample]
|
||||
d_carrier_phase_step_rad = GLONASS_TWO_PI * d_carrier_doppler_hz / static_cast<double>(d_fs_in);
|
||||
d_acc_carrier_phase_cycles -= d_carrier_phase_step_rad * d_correlation_length_samples / GLONASS_TWO_PI;
|
||||
// UPDATE ACCUMULATED CARRIER PHASE
|
||||
CORRECTED_INTEGRATION_TIME_S = (static_cast<double>(d_correlation_length_samples) / static_cast<double>(d_fs_in));
|
||||
//remnant carrier phase [rad]
|
||||
d_rem_carrier_phase_rad = fmod(d_rem_carrier_phase_rad + GLONASS_TWO_PI * d_carrier_doppler_hz * CORRECTED_INTEGRATION_TIME_S, GLONASS_TWO_PI);
|
||||
|
||||
//################### DLL COMMANDS #################################################
|
||||
//code phase step (Code resampler phase increment per sample) [chips/sample]
|
||||
d_code_phase_step_chips = d_code_freq_chips / static_cast<double>(d_fs_in);
|
||||
//remnant code phase [chips]
|
||||
d_rem_code_phase_chips = d_rem_code_phase_samples * (d_code_freq_chips / static_cast<double>(d_fs_in));
|
||||
|
||||
// ####### CN0 ESTIMATION AND LOCK DETECTORS #######################################
|
||||
if (d_cn0_estimation_counter < CN0_ESTIMATION_SAMPLES)
|
||||
{
|
||||
// fill buffer with prompt correlator output values
|
||||
d_Prompt_buffer[d_cn0_estimation_counter] = d_correlator_outs[1]; // prompt
|
||||
d_cn0_estimation_counter++;
|
||||
}
|
||||
else
|
||||
{
|
||||
d_cn0_estimation_counter = 0;
|
||||
// Code lock indicator
|
||||
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, d_fs_in, GLONASS_L1_CA_CODE_LENGTH_CHIPS);
|
||||
// Carrier lock indicator
|
||||
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES);
|
||||
// Loss of lock detection
|
||||
if (d_carrier_lock_test < d_carrier_lock_threshold or d_CN0_SNV_dB_Hz < MINIMUM_VALID_CN0)
|
||||
{
|
||||
d_carrier_lock_fail_counter++;
|
||||
}
|
||||
else
|
||||
{
|
||||
if (d_carrier_lock_fail_counter > 0) d_carrier_lock_fail_counter--;
|
||||
}
|
||||
if (d_carrier_lock_fail_counter > MAXIMUM_LOCK_FAIL_COUNTER)
|
||||
{
|
||||
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;
|
||||
d_enable_tracking = false; // TODO: check if disabling tracking is consistent with the channel state machine
|
||||
}
|
||||
}
|
||||
// ########### Output the tracking data to navigation and PVT ##########
|
||||
current_synchro_data.Prompt_I = static_cast<double>((d_correlator_outs[1]).real());
|
||||
current_synchro_data.Prompt_Q = static_cast<double>((d_correlator_outs[1]).imag());
|
||||
current_synchro_data.Tracking_sample_counter = d_sample_counter + d_correlation_length_samples;
|
||||
current_synchro_data.Code_phase_samples = d_rem_code_phase_samples;
|
||||
current_synchro_data.Carrier_phase_rads = GLONASS_TWO_PI * d_acc_carrier_phase_cycles;
|
||||
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;
|
||||
if (d_preamble_synchronized == true)
|
||||
{
|
||||
current_synchro_data.correlation_length_ms = d_extend_correlation_ms;
|
||||
}
|
||||
else
|
||||
{
|
||||
current_synchro_data.correlation_length_ms = 1;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
current_synchro_data.Prompt_I = static_cast<double>((d_correlator_outs[1]).real());
|
||||
current_synchro_data.Prompt_Q = static_cast<double>((d_correlator_outs[1]).imag());
|
||||
current_synchro_data.Tracking_sample_counter = d_sample_counter + d_correlation_length_samples;
|
||||
current_synchro_data.Code_phase_samples = d_rem_code_phase_samples;
|
||||
current_synchro_data.Carrier_phase_rads = GLONASS_TWO_PI * d_acc_carrier_phase_cycles;
|
||||
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;// todo: project the carrier doppler
|
||||
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
for (int n = 0; n < d_n_correlator_taps; n++)
|
||||
{
|
||||
d_correlator_outs[n] = gr_complex(0,0);
|
||||
}
|
||||
|
||||
current_synchro_data.System = {'R'};
|
||||
current_synchro_data.Tracking_sample_counter = d_sample_counter + d_correlation_length_samples;
|
||||
}
|
||||
//assign the GNURadio block output data
|
||||
current_synchro_data.fs=d_fs_in;
|
||||
*out[0] = current_synchro_data;
|
||||
if(d_dump)
|
||||
{
|
||||
// MULTIPLEXED FILE RECORDING - Record results to file
|
||||
float prompt_I;
|
||||
float prompt_Q;
|
||||
float tmp_E, tmp_P, tmp_L;
|
||||
double tmp_double;
|
||||
prompt_I = d_correlator_outs[1].real();
|
||||
prompt_Q = d_correlator_outs[1].imag();
|
||||
tmp_E = std::abs<float>(d_correlator_outs[0]);
|
||||
tmp_P = std::abs<float>(d_correlator_outs[1]);
|
||||
tmp_L = std::abs<float>(d_correlator_outs[2]);
|
||||
try
|
||||
{
|
||||
// EPR
|
||||
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));
|
||||
// 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_float=(float)d_sample_counter;
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_sample_counter), sizeof(unsigned long int));
|
||||
// accumulated carrier phase
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_acc_carrier_phase_cycles), sizeof(double));
|
||||
|
||||
// carrier and code frequency
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_carrier_doppler_hz), sizeof(double));
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_code_freq_chips), sizeof(double));
|
||||
|
||||
//PLL commands
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_carr_phase_error_secs_Ti), sizeof(double));
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_carrier_doppler_hz), sizeof(double));
|
||||
|
||||
//DLL commands
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_code_error_chips_Ti), sizeof(double));
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_code_error_filt_chips_Ti), sizeof(double));
|
||||
|
||||
// CN0 and carrier lock test
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_CN0_SNV_dB_Hz), sizeof(double));
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_carrier_lock_test), sizeof(double));
|
||||
|
||||
// AUX vars (for debug purposes)
|
||||
tmp_double = d_code_error_chips_Ti * CURRENT_INTEGRATION_TIME_S;
|
||||
d_dump_file.write(reinterpret_cast<char*>(&tmp_double), sizeof(double));
|
||||
tmp_double = static_cast<double>(d_sample_counter + d_correlation_length_samples);
|
||||
d_dump_file.write(reinterpret_cast<char*>(&tmp_double), sizeof(double));
|
||||
|
||||
// PRN
|
||||
unsigned int prn_ = d_acquisition_gnss_synchro->PRN;
|
||||
d_dump_file.write(reinterpret_cast<char*>(&prn_), sizeof(unsigned int));
|
||||
}
|
||||
catch (const std::ifstream::failure* e)
|
||||
{
|
||||
LOG(WARNING) << "Exception writing trk dump file " << e->what();
|
||||
}
|
||||
}
|
||||
|
||||
consume_each(d_correlation_length_samples); // this is necessary in gr::block derivates
|
||||
d_sample_counter += d_correlation_length_samples; //count for the processed samples
|
||||
|
||||
return 1; //output tracking result ALWAYS even in the case of d_enable_tracking==false
|
||||
}
|
||||
|
||||
|
||||
void glonass_l1_ca_dll_pll_c_aid_tracking_cc::set_channel(unsigned int channel)
|
||||
{
|
||||
d_channel = channel;
|
||||
LOG(INFO) << "Tracking Channel set to " << d_channel;
|
||||
// ############# ENABLE DATA FILE LOG #################
|
||||
if (d_dump == true)
|
||||
{
|
||||
if (d_dump_file.is_open() == false)
|
||||
{
|
||||
try
|
||||
{
|
||||
d_dump_filename.append(boost::lexical_cast<std::string>(d_channel));
|
||||
d_dump_filename.append(".dat");
|
||||
d_dump_file.exceptions (std::ifstream::failbit | std::ifstream::badbit);
|
||||
d_dump_file.open(d_dump_filename.c_str(), std::ios::out | std::ios::binary);
|
||||
LOG(INFO) << "Tracking dump enabled on channel " << d_channel << " Log file: " << d_dump_filename.c_str() << std::endl;
|
||||
}
|
||||
catch (const std::ifstream::failure* e)
|
||||
{
|
||||
LOG(WARNING) << "channel " << d_channel << " Exception opening trk dump file " << e->what() << std::endl;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
|
||||
void glonass_l1_ca_dll_pll_c_aid_tracking_cc::set_gnss_synchro(Gnss_Synchro* p_gnss_synchro)
|
||||
{
|
||||
d_acquisition_gnss_synchro = p_gnss_synchro;
|
||||
}
|
||||
@ -0,0 +1,167 @@
|
||||
#ifndef GNSS_SDR_GLONASS_L1_CA_DLL_PLL_C_AID_TRACKING_CC_H
|
||||
#define GNSS_SDR_GLONASS_L1_CA_DLL_PLL_C_AID_TRACKING_CC_H
|
||||
|
||||
#include <fstream>
|
||||
#include <map>
|
||||
#include <deque>
|
||||
#include <string>
|
||||
#include <gnuradio/block.h>
|
||||
#include <pmt/pmt.h>
|
||||
#include "gnss_synchro.h"
|
||||
#include "tracking_2nd_DLL_filter.h"
|
||||
#include "tracking_FLL_PLL_filter.h"
|
||||
//#include "tracking_loop_filter.h"
|
||||
#include "cpu_multicorrelator.h"
|
||||
|
||||
class glonass_l1_ca_dll_pll_c_aid_tracking_cc;
|
||||
|
||||
typedef boost::shared_ptr<glonass_l1_ca_dll_pll_c_aid_tracking_cc>
|
||||
glonass_l1_ca_dll_pll_c_aid_tracking_cc_sptr;
|
||||
|
||||
glonass_l1_ca_dll_pll_c_aid_tracking_cc_sptr
|
||||
glonass_l1_ca_dll_pll_c_aid_make_tracking_cc(long if_freq,
|
||||
long fs_in, unsigned
|
||||
int vector_length,
|
||||
bool dump,
|
||||
std::string dump_filename,
|
||||
float pll_bw_hz,
|
||||
float dll_bw_hz,
|
||||
float pll_bw_narrow_hz,
|
||||
float dll_bw_narrow_hz,
|
||||
int extend_correlation_ms,
|
||||
float early_late_space_chips);
|
||||
|
||||
|
||||
|
||||
/*!
|
||||
* \brief This class implements a DLL + PLL tracking loop block
|
||||
*/
|
||||
class glonass_l1_ca_dll_pll_c_aid_tracking_cc: public gr::block
|
||||
{
|
||||
public:
|
||||
~glonass_l1_ca_dll_pll_c_aid_tracking_cc();
|
||||
|
||||
void set_channel(unsigned int channel);
|
||||
void set_gnss_synchro(Gnss_Synchro* p_gnss_synchro);
|
||||
void start_tracking();
|
||||
|
||||
int general_work (int noutput_items, gr_vector_int &ninput_items,
|
||||
gr_vector_const_void_star &input_items, gr_vector_void_star &output_items);
|
||||
|
||||
void forecast (int noutput_items, gr_vector_int &ninput_items_required);
|
||||
|
||||
private:
|
||||
friend glonass_l1_ca_dll_pll_c_aid_tracking_cc_sptr
|
||||
glonass_l1_ca_dll_pll_c_aid_make_tracking_cc(long if_freq,
|
||||
long fs_in, unsigned
|
||||
int vector_length,
|
||||
bool dump,
|
||||
std::string dump_filename,
|
||||
float pll_bw_hz,
|
||||
float dll_bw_hz,
|
||||
float pll_bw_narrow_hz,
|
||||
float dll_bw_narrow_hz,
|
||||
int extend_correlation_ms,
|
||||
float early_late_space_chips);
|
||||
|
||||
glonass_l1_ca_dll_pll_c_aid_tracking_cc(long if_freq,
|
||||
long fs_in, unsigned
|
||||
int vector_length,
|
||||
bool dump,
|
||||
std::string dump_filename,
|
||||
float pll_bw_hz,
|
||||
float dll_bw_hz,
|
||||
float pll_bw_narrow_hz,
|
||||
float dll_bw_narrow_hz,
|
||||
int extend_correlation_ms,
|
||||
float early_late_space_chips);
|
||||
|
||||
// tracking configuration vars
|
||||
unsigned int d_vector_length;
|
||||
bool d_dump;
|
||||
|
||||
Gnss_Synchro* d_acquisition_gnss_synchro;
|
||||
unsigned int d_channel;
|
||||
|
||||
long d_if_freq;
|
||||
long d_fs_in;
|
||||
long d_glonass_freq_ch;
|
||||
|
||||
double d_early_late_spc_chips;
|
||||
int d_n_correlator_taps;
|
||||
|
||||
gr_complex* d_ca_code;
|
||||
float* d_local_code_shift_chips;
|
||||
gr_complex* d_correlator_outs;
|
||||
cpu_multicorrelator multicorrelator_cpu;
|
||||
|
||||
// remaining code phase and carrier phase between tracking loops
|
||||
double d_rem_code_phase_samples;
|
||||
double d_rem_code_phase_chips;
|
||||
double d_rem_carrier_phase_rad;
|
||||
int d_rem_code_phase_integer_samples;
|
||||
|
||||
// PLL and DLL filter library
|
||||
//Tracking_2nd_DLL_filter d_code_loop_filter;
|
||||
Tracking_2nd_DLL_filter d_code_loop_filter;
|
||||
Tracking_FLL_PLL_filter d_carrier_loop_filter;
|
||||
|
||||
// acquisition
|
||||
double d_acq_code_phase_samples;
|
||||
double d_acq_carrier_doppler_hz;
|
||||
|
||||
// tracking vars
|
||||
float d_dll_bw_hz;
|
||||
float d_pll_bw_hz;
|
||||
float d_dll_bw_narrow_hz;
|
||||
float d_pll_bw_narrow_hz;
|
||||
double d_code_freq_chips;
|
||||
double d_code_phase_step_chips;
|
||||
double d_carrier_doppler_hz;
|
||||
double d_carrier_phase_step_rad;
|
||||
double d_acc_carrier_phase_cycles;
|
||||
double d_code_phase_samples;
|
||||
double d_pll_to_dll_assist_secs_Ti;
|
||||
double d_code_error_chips_Ti;
|
||||
double d_code_error_filt_chips_s;
|
||||
double d_code_error_filt_chips_Ti;
|
||||
double d_carr_phase_error_secs_Ti;
|
||||
|
||||
// symbol history to detect bit transition
|
||||
std::deque<gr_complex> d_E_history;
|
||||
std::deque<gr_complex> d_P_history;
|
||||
std::deque<gr_complex> d_L_history;
|
||||
double d_preamble_timestamp_s;
|
||||
int d_extend_correlation_ms;
|
||||
bool d_enable_extended_integration;
|
||||
bool d_preamble_synchronized;
|
||||
void msg_handler_preamble_index(pmt::pmt_t msg);
|
||||
|
||||
//Integration period in samples
|
||||
int d_correlation_length_samples;
|
||||
|
||||
//processing samples counters
|
||||
unsigned long int d_sample_counter;
|
||||
unsigned long int d_acq_sample_stamp;
|
||||
|
||||
// CN0 estimation and lock detector
|
||||
int d_cn0_estimation_counter;
|
||||
gr_complex* d_Prompt_buffer;
|
||||
double d_carrier_lock_test;
|
||||
double d_CN0_SNV_dB_Hz;
|
||||
double d_carrier_lock_threshold;
|
||||
int d_carrier_lock_fail_counter;
|
||||
|
||||
// control vars
|
||||
bool d_enable_tracking;
|
||||
bool d_pull_in;
|
||||
|
||||
// file dump
|
||||
std::string d_dump_filename;
|
||||
std::ofstream d_dump_file;
|
||||
|
||||
std::map<std::string, std::string> systemName;
|
||||
std::string sys;
|
||||
};
|
||||
|
||||
#endif //GNSS_SDR_GLONASS_L1_CA_DLL_PLL_C_AID_TRACKING_CC_H
|
||||
@ -0,0 +1,648 @@
|
||||
#include "glonass_l1_ca_dll_pll_c_aid_tracking_sc.h"
|
||||
#include <cmath>
|
||||
#include <iostream>
|
||||
#include <memory>
|
||||
#include <sstream>
|
||||
#include <boost/bind.hpp>
|
||||
#include <boost/lexical_cast.hpp>
|
||||
#include <gnuradio/io_signature.h>
|
||||
#include <pmt/pmt.h>
|
||||
#include <volk_gnsssdr/volk_gnsssdr.h>
|
||||
#include <glog/logging.h>
|
||||
#include "gnss_synchro.h"
|
||||
#include "glonass_l1_signal_processing.h"
|
||||
#include "tracking_discriminators.h"
|
||||
#include "lock_detectors.h"
|
||||
#include "Glonass_L1_CA.h"
|
||||
#include "control_message_factory.h"
|
||||
|
||||
|
||||
/*!
|
||||
* \todo Include in definition header file
|
||||
*/
|
||||
#define CN0_ESTIMATION_SAMPLES 20
|
||||
#define MINIMUM_VALID_CN0 25
|
||||
#define MAXIMUM_LOCK_FAIL_COUNTER 50
|
||||
#define CARRIER_LOCK_THRESHOLD 0.85
|
||||
|
||||
|
||||
using google::LogMessage;
|
||||
|
||||
glonass_l1_ca_dll_pll_c_aid_tracking_sc_sptr
|
||||
glonass_l1_ca_dll_pll_c_aid_make_tracking_sc(
|
||||
long if_freq,
|
||||
long fs_in,
|
||||
unsigned int vector_length,
|
||||
bool dump,
|
||||
std::string dump_filename,
|
||||
float pll_bw_hz,
|
||||
float dll_bw_hz,
|
||||
float pll_bw_narrow_hz,
|
||||
float dll_bw_narrow_hz,
|
||||
int extend_correlation_ms,
|
||||
float early_late_space_chips)
|
||||
{
|
||||
return glonass_l1_ca_dll_pll_c_aid_tracking_sc_sptr(new glonass_l1_ca_dll_pll_c_aid_tracking_sc(if_freq,
|
||||
fs_in, vector_length, dump, dump_filename, pll_bw_hz, dll_bw_hz, pll_bw_narrow_hz, dll_bw_narrow_hz, extend_correlation_ms, early_late_space_chips));
|
||||
}
|
||||
|
||||
|
||||
|
||||
void glonass_l1_ca_dll_pll_c_aid_tracking_sc::forecast (int noutput_items,
|
||||
gr_vector_int &ninput_items_required)
|
||||
{
|
||||
if (noutput_items != 0)
|
||||
{
|
||||
ninput_items_required[0] = static_cast<int>(d_vector_length) * 2; //set the required available samples in each call
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
void glonass_l1_ca_dll_pll_c_aid_tracking_sc::msg_handler_preamble_index(pmt::pmt_t msg)
|
||||
{
|
||||
//pmt::print(msg);
|
||||
DLOG(INFO) << "Extended correlation enabled for Tracking CH " << d_channel << ": Satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN);
|
||||
if (d_enable_extended_integration == false) //avoid re-setting preamble indicator
|
||||
{
|
||||
d_preamble_timestamp_s = pmt::to_double(msg);
|
||||
d_enable_extended_integration = true;
|
||||
d_preamble_synchronized = false;
|
||||
}
|
||||
}
|
||||
|
||||
glonass_l1_ca_dll_pll_c_aid_tracking_sc::glonass_l1_ca_dll_pll_c_aid_tracking_sc(
|
||||
long if_freq,
|
||||
long fs_in,
|
||||
unsigned int vector_length,
|
||||
bool dump,
|
||||
std::string dump_filename,
|
||||
float pll_bw_hz,
|
||||
float dll_bw_hz,
|
||||
float pll_bw_narrow_hz,
|
||||
float dll_bw_narrow_hz,
|
||||
int extend_correlation_ms,
|
||||
float early_late_space_chips) :
|
||||
gr::block("glonass_l1_ca_dll_pll_c_aid_tracking_sc", gr::io_signature::make(1, 1, sizeof(lv_16sc_t)),
|
||||
gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)))
|
||||
{
|
||||
// Telemetry bit synchronization message port input
|
||||
this->message_port_register_in(pmt::mp("preamble_timestamp_s"));
|
||||
this->set_msg_handler(pmt::mp("preamble_timestamp_s"),
|
||||
boost::bind(&glonass_l1_ca_dll_pll_c_aid_tracking_sc::msg_handler_preamble_index, this, _1));
|
||||
this->message_port_register_out(pmt::mp("events"));
|
||||
// initialize internal vars
|
||||
d_dump = dump;
|
||||
d_if_freq = if_freq;
|
||||
d_fs_in = fs_in;
|
||||
d_vector_length = vector_length;
|
||||
d_dump_filename = dump_filename;
|
||||
d_correlation_length_samples = static_cast<int>(d_vector_length);
|
||||
|
||||
// Initialize tracking ==========================================
|
||||
d_pll_bw_hz = pll_bw_hz;
|
||||
d_dll_bw_hz = dll_bw_hz;
|
||||
d_pll_bw_narrow_hz = pll_bw_narrow_hz;
|
||||
d_dll_bw_narrow_hz = dll_bw_narrow_hz;
|
||||
d_code_loop_filter.set_DLL_BW(d_dll_bw_hz);
|
||||
d_carrier_loop_filter.set_params(10.0, d_pll_bw_hz, 2);
|
||||
d_extend_correlation_ms = extend_correlation_ms;
|
||||
|
||||
// --- DLL variables --------------------------------------------------------
|
||||
d_early_late_spc_chips = early_late_space_chips; // Define early-late offset (in chips)
|
||||
|
||||
// Initialization of local code replica
|
||||
// Get space for a vector with the C/A code replica sampled 1x/chip
|
||||
d_ca_code = static_cast<gr_complex*>(volk_gnsssdr_malloc(static_cast<int>(GLONASS_L1_CA_CODE_LENGTH_CHIPS) * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
|
||||
d_ca_code_16sc = static_cast<lv_16sc_t*>(volk_gnsssdr_malloc(static_cast<int>(GLONASS_L1_CA_CODE_LENGTH_CHIPS) * sizeof(lv_16sc_t), volk_gnsssdr_get_alignment()));
|
||||
|
||||
// correlator outputs (scalar)
|
||||
d_n_correlator_taps = 3; // Early, Prompt, and Late
|
||||
|
||||
d_correlator_outs_16sc = static_cast<lv_16sc_t*>(volk_gnsssdr_malloc(d_n_correlator_taps*sizeof(lv_16sc_t), volk_gnsssdr_get_alignment()));
|
||||
for (int n = 0; n < d_n_correlator_taps; n++)
|
||||
{
|
||||
d_correlator_outs_16sc[n] = lv_cmake(0,0);
|
||||
}
|
||||
|
||||
d_local_code_shift_chips = static_cast<float*>(volk_gnsssdr_malloc(d_n_correlator_taps*sizeof(float), volk_gnsssdr_get_alignment()));
|
||||
// Set TAPs delay values [chips]
|
||||
d_local_code_shift_chips[0] = - d_early_late_spc_chips;
|
||||
d_local_code_shift_chips[1] = 0.0;
|
||||
d_local_code_shift_chips[2] = d_early_late_spc_chips;
|
||||
|
||||
multicorrelator_cpu_16sc.init(2 * d_correlation_length_samples, d_n_correlator_taps);
|
||||
|
||||
//--- Perform initializations ------------------------------
|
||||
// define initial code frequency basis of NCO
|
||||
d_code_freq_chips = GLONASS_L1_CA_CODE_RATE_HZ;
|
||||
// define residual code phase (in chips)
|
||||
d_rem_code_phase_samples = 0.0;
|
||||
// define residual carrier phase
|
||||
d_rem_carrier_phase_rad = 0.0;
|
||||
|
||||
// sample synchronization
|
||||
d_sample_counter = 0; //(from trk to tlm)
|
||||
d_acq_sample_stamp = 0;
|
||||
d_enable_tracking = false;
|
||||
d_pull_in = false;
|
||||
|
||||
// CN0 estimation and lock detector buffers
|
||||
d_cn0_estimation_counter = 0;
|
||||
d_Prompt_buffer = new gr_complex[CN0_ESTIMATION_SAMPLES];
|
||||
d_carrier_lock_test = 1;
|
||||
d_CN0_SNV_dB_Hz = 0;
|
||||
d_carrier_lock_fail_counter = 0;
|
||||
d_carrier_lock_threshold = CARRIER_LOCK_THRESHOLD;
|
||||
|
||||
systemName["R"] = std::string("Glonass");
|
||||
|
||||
set_relative_rate(1.0 / static_cast<double>(d_vector_length));
|
||||
|
||||
d_acquisition_gnss_synchro = 0;
|
||||
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_cycles = 0.0;
|
||||
d_code_phase_samples = 0.0;
|
||||
d_enable_extended_integration = false;
|
||||
d_preamble_synchronized = false;
|
||||
d_rem_code_phase_integer_samples = 0;
|
||||
d_code_error_chips_Ti = 0.0;
|
||||
d_pll_to_dll_assist_secs_Ti = 0.0;
|
||||
d_rem_code_phase_chips = 0.0;
|
||||
d_code_phase_step_chips = 0.0;
|
||||
d_carrier_phase_step_rad = 0.0;
|
||||
d_code_error_filt_chips_s = 0.0;
|
||||
d_code_error_filt_chips_Ti = 0.0;
|
||||
d_preamble_timestamp_s = 0.0;
|
||||
d_carr_phase_error_secs_Ti = 0.0;
|
||||
//set_min_output_buffer((long int)300);
|
||||
}
|
||||
|
||||
|
||||
void glonass_l1_ca_dll_pll_c_aid_tracking_sc::start_tracking()
|
||||
{
|
||||
/*
|
||||
* 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;
|
||||
|
||||
long int acq_trk_diff_samples;
|
||||
double acq_trk_diff_seconds;
|
||||
acq_trk_diff_samples = static_cast<long int>(d_sample_counter) - static_cast<long int>(d_acq_sample_stamp);//-d_vector_length;
|
||||
DLOG(INFO) << "Number of samples between Acquisition and Tracking =" << acq_trk_diff_samples;
|
||||
acq_trk_diff_seconds = static_cast<double>(acq_trk_diff_samples) / static_cast<double>(d_fs_in);
|
||||
// Doppler effect
|
||||
// Fd=(C/(C+Vr))*F
|
||||
d_glonass_freq_ch = GLONASS_L1_FREQ_HZ + (GLONASS_L1_FREQ_HZ * GLONASS_PRN.at(d_acquisition_gnss_synchro->PRN));
|
||||
double radial_velocity = (d_glonass_freq_ch + d_acq_carrier_doppler_hz) / d_glonass_freq_ch;
|
||||
// new chip and prn sequence periods based on acq Doppler
|
||||
double T_chip_mod_seconds;
|
||||
double T_prn_mod_seconds;
|
||||
double T_prn_mod_samples;
|
||||
d_code_freq_chips = radial_velocity * GLONASS_L1_CA_CODE_RATE_HZ;
|
||||
d_code_phase_step_chips = static_cast<double>(d_code_freq_chips) / static_cast<double>(d_fs_in);
|
||||
T_chip_mod_seconds = 1.0 / d_code_freq_chips;
|
||||
T_prn_mod_seconds = T_chip_mod_seconds * GLONASS_L1_CA_CODE_LENGTH_CHIPS;
|
||||
T_prn_mod_samples = T_prn_mod_seconds * static_cast<double>(d_fs_in);
|
||||
|
||||
d_correlation_length_samples = round(T_prn_mod_samples);
|
||||
|
||||
double T_prn_true_seconds = GLONASS_L1_CA_CODE_LENGTH_CHIPS / GLONASS_L1_CA_CODE_RATE_HZ;
|
||||
double T_prn_true_samples = T_prn_true_seconds * static_cast<double>(d_fs_in);
|
||||
double T_prn_diff_seconds = T_prn_true_seconds - T_prn_mod_seconds;
|
||||
double N_prn_diff = acq_trk_diff_seconds / T_prn_true_seconds;
|
||||
double corrected_acq_phase_samples, delay_correction_samples;
|
||||
corrected_acq_phase_samples = fmod((d_acq_code_phase_samples + T_prn_diff_seconds * N_prn_diff * static_cast<double>(d_fs_in)), T_prn_true_samples);
|
||||
if (corrected_acq_phase_samples < 0)
|
||||
{
|
||||
corrected_acq_phase_samples = T_prn_mod_samples + corrected_acq_phase_samples;
|
||||
}
|
||||
delay_correction_samples = d_acq_code_phase_samples - corrected_acq_phase_samples;
|
||||
|
||||
d_acq_code_phase_samples = corrected_acq_phase_samples;
|
||||
|
||||
d_carrier_doppler_hz = d_acq_carrier_doppler_hz;
|
||||
|
||||
d_carrier_phase_step_rad = GLONASS_TWO_PI * d_carrier_doppler_hz / static_cast<double>(d_fs_in);
|
||||
|
||||
// DLL/PLL filter initialization
|
||||
d_carrier_loop_filter.initialize(d_acq_carrier_doppler_hz); // The carrier loop filter implements the Doppler accumulator
|
||||
d_code_loop_filter.initialize(); // initialize the code filter
|
||||
|
||||
// generate local reference ALWAYS starting at chip 1 (1 sample per chip)
|
||||
glonass_l1_ca_code_gen_complex(d_ca_code, 0);
|
||||
volk_gnsssdr_32fc_convert_16ic(d_ca_code_16sc, d_ca_code, static_cast<int>(GLONASS_L1_CA_CODE_LENGTH_CHIPS));
|
||||
|
||||
multicorrelator_cpu_16sc.set_local_code_and_taps(static_cast<int>(GLONASS_L1_CA_CODE_LENGTH_CHIPS), d_ca_code_16sc, d_local_code_shift_chips);
|
||||
for (int n = 0; n < d_n_correlator_taps; n++)
|
||||
{
|
||||
d_correlator_outs_16sc[n] = lv_16sc_t(0,0);
|
||||
}
|
||||
|
||||
d_carrier_lock_fail_counter = 0;
|
||||
d_rem_code_phase_samples = 0.0;
|
||||
d_rem_carrier_phase_rad = 0.0;
|
||||
d_rem_code_phase_chips = 0.0;
|
||||
d_acc_carrier_phase_cycles = 0.0;
|
||||
d_pll_to_dll_assist_secs_Ti = 0.0;
|
||||
d_code_phase_samples = d_acq_code_phase_samples;
|
||||
|
||||
std::string sys_ = &d_acquisition_gnss_synchro->System;
|
||||
sys = sys_.substr(0,1);
|
||||
|
||||
// DEBUG OUTPUT
|
||||
std::cout << "Tracking start on channel " << d_channel << " for satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << std::endl;
|
||||
LOG(INFO) << "Starting tracking of satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << " on channel " << d_channel;
|
||||
|
||||
// enable tracking
|
||||
d_pull_in = true;
|
||||
d_enable_tracking = true;
|
||||
d_enable_extended_integration = true;
|
||||
d_preamble_synchronized = true;
|
||||
|
||||
LOG(INFO) << "PULL-IN Doppler [Hz]=" << d_carrier_doppler_hz
|
||||
<< " Code Phase correction [samples]=" << delay_correction_samples
|
||||
<< " PULL-IN Code Phase [samples]=" << d_acq_code_phase_samples;
|
||||
}
|
||||
|
||||
|
||||
glonass_l1_ca_dll_pll_c_aid_tracking_sc::~glonass_l1_ca_dll_pll_c_aid_tracking_sc()
|
||||
{
|
||||
d_dump_file.close();
|
||||
|
||||
volk_gnsssdr_free(d_local_code_shift_chips);
|
||||
volk_gnsssdr_free(d_ca_code);
|
||||
volk_gnsssdr_free(d_ca_code_16sc);
|
||||
volk_gnsssdr_free(d_correlator_outs_16sc);
|
||||
|
||||
delete[] d_Prompt_buffer;
|
||||
multicorrelator_cpu_16sc.free();
|
||||
}
|
||||
|
||||
|
||||
|
||||
int glonass_l1_ca_dll_pll_c_aid_tracking_sc::general_work (int noutput_items __attribute__((unused)), gr_vector_int &ninput_items __attribute__((unused)),
|
||||
gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)
|
||||
{
|
||||
// Block input data and block output stream pointers
|
||||
const lv_16sc_t* in = (lv_16sc_t*) input_items[0]; //PRN start block alignment
|
||||
Gnss_Synchro **out = (Gnss_Synchro **) &output_items[0];
|
||||
|
||||
// GNSS_SYNCHRO OBJECT to interchange data between tracking->telemetry_decoder
|
||||
Gnss_Synchro current_synchro_data = Gnss_Synchro();
|
||||
|
||||
// process vars
|
||||
double code_error_filt_secs_Ti = 0.0;
|
||||
double CURRENT_INTEGRATION_TIME_S = 0.0;
|
||||
double CORRECTED_INTEGRATION_TIME_S = 0.0;
|
||||
|
||||
if (d_enable_tracking == true)
|
||||
{
|
||||
// Fill the acquisition data
|
||||
current_synchro_data = *d_acquisition_gnss_synchro;
|
||||
// Receiver signal alignment
|
||||
if (d_pull_in == true)
|
||||
{
|
||||
int samples_offset;
|
||||
double acq_trk_shif_correction_samples;
|
||||
int acq_to_trk_delay_samples;
|
||||
acq_to_trk_delay_samples = d_sample_counter - d_acq_sample_stamp;
|
||||
acq_trk_shif_correction_samples = d_correlation_length_samples - fmod(static_cast<double>(acq_to_trk_delay_samples), static_cast<double>(d_correlation_length_samples));
|
||||
samples_offset = round(d_acq_code_phase_samples + acq_trk_shif_correction_samples);
|
||||
current_synchro_data.Tracking_sample_counter = d_sample_counter + samples_offset;
|
||||
d_sample_counter += samples_offset; // count for the processed samples
|
||||
d_pull_in = false;
|
||||
d_acc_carrier_phase_cycles -= d_carrier_phase_step_rad * samples_offset / GLONASS_TWO_PI;
|
||||
current_synchro_data.Carrier_phase_rads = d_acc_carrier_phase_cycles * GLONASS_TWO_PI;
|
||||
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;
|
||||
current_synchro_data.fs=d_fs_in;
|
||||
*out[0] = current_synchro_data;
|
||||
consume_each(samples_offset); // shift input to perform alignment with local replica
|
||||
return 1;
|
||||
}
|
||||
|
||||
// ################# CARRIER WIPEOFF AND CORRELATORS ##############################
|
||||
// perform carrier wipe-off and compute Early, Prompt and Late correlation
|
||||
multicorrelator_cpu_16sc.set_input_output_vectors(d_correlator_outs_16sc, in);
|
||||
multicorrelator_cpu_16sc.Carrier_wipeoff_multicorrelator_resampler(d_rem_carrier_phase_rad,
|
||||
d_carrier_phase_step_rad,
|
||||
d_rem_code_phase_chips,
|
||||
d_code_phase_step_chips,
|
||||
d_correlation_length_samples);
|
||||
|
||||
// ####### coherent intergration extension
|
||||
// keep the last symbols
|
||||
d_E_history.push_back(d_correlator_outs_16sc[0]); // save early output
|
||||
d_P_history.push_back(d_correlator_outs_16sc[1]); // save prompt output
|
||||
d_L_history.push_back(d_correlator_outs_16sc[2]); // save late output
|
||||
|
||||
if (static_cast<int>(d_P_history.size()) > d_extend_correlation_ms)
|
||||
{
|
||||
d_E_history.pop_front();
|
||||
d_P_history.pop_front();
|
||||
d_L_history.pop_front();
|
||||
}
|
||||
|
||||
bool enable_dll_pll;
|
||||
if (d_enable_extended_integration == true)
|
||||
{
|
||||
long int symbol_diff = round(1000.0 * ((static_cast<double>(d_sample_counter) + d_rem_code_phase_samples) / static_cast<double>(d_fs_in) - d_preamble_timestamp_s));
|
||||
if (symbol_diff > 0 and symbol_diff % d_extend_correlation_ms == 0)
|
||||
{
|
||||
// compute coherent integration and enable tracking loop
|
||||
// perform coherent integration using correlator output history
|
||||
// std::cout<<"##### RESET COHERENT INTEGRATION ####"<<std::endl;
|
||||
d_correlator_outs_16sc[0] = lv_cmake(0,0);
|
||||
d_correlator_outs_16sc[1] = lv_cmake(0,0);
|
||||
d_correlator_outs_16sc[2] = lv_cmake(0,0);
|
||||
for (int n = 0; n < d_extend_correlation_ms; n++)
|
||||
{
|
||||
d_correlator_outs_16sc[0] += d_E_history.at(n);
|
||||
d_correlator_outs_16sc[1] += d_P_history.at(n);
|
||||
d_correlator_outs_16sc[2] += d_L_history.at(n);
|
||||
}
|
||||
|
||||
if (d_preamble_synchronized == false)
|
||||
{
|
||||
d_code_loop_filter.set_DLL_BW(d_dll_bw_narrow_hz);
|
||||
d_carrier_loop_filter.set_params(10.0, d_pll_bw_narrow_hz,2);
|
||||
d_preamble_synchronized = true;
|
||||
std::cout << "Enabled " << d_extend_correlation_ms << " [ms] extended correlator for CH "<< d_channel << " : Satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN)
|
||||
<< " pll_bw = " << d_pll_bw_hz << " [Hz], pll_narrow_bw = " << d_pll_bw_narrow_hz << " [Hz]" << std::endl
|
||||
<< " dll_bw = " << d_dll_bw_hz << " [Hz], dll_narrow_bw = " << d_dll_bw_narrow_hz << " [Hz]" << std::endl;
|
||||
}
|
||||
// UPDATE INTEGRATION TIME
|
||||
CURRENT_INTEGRATION_TIME_S = static_cast<double>(d_extend_correlation_ms) * GLONASS_L1_CA_CODE_PERIOD;
|
||||
enable_dll_pll = true;
|
||||
}
|
||||
else
|
||||
{
|
||||
if(d_preamble_synchronized == true)
|
||||
{
|
||||
// continue extended coherent correlation
|
||||
// Compute the next buffer length based on the period of the PRN sequence and the code phase error estimation
|
||||
double T_chip_seconds = 1.0 / d_code_freq_chips;
|
||||
double T_prn_seconds = T_chip_seconds * GLONASS_L1_CA_CODE_LENGTH_CHIPS;
|
||||
double T_prn_samples = T_prn_seconds * static_cast<double>(d_fs_in);
|
||||
int K_prn_samples = round(T_prn_samples);
|
||||
double K_T_prn_error_samples = K_prn_samples - T_prn_samples;
|
||||
|
||||
d_rem_code_phase_samples = d_rem_code_phase_samples - K_T_prn_error_samples;
|
||||
d_rem_code_phase_integer_samples = round(d_rem_code_phase_samples); // round to a discrete number of samples
|
||||
d_correlation_length_samples = K_prn_samples + d_rem_code_phase_integer_samples;
|
||||
d_rem_code_phase_samples = d_rem_code_phase_samples - d_rem_code_phase_integer_samples;
|
||||
// code phase step (Code resampler phase increment per sample) [chips/sample]
|
||||
d_code_phase_step_chips = d_code_freq_chips / static_cast<double>(d_fs_in);
|
||||
// remnant code phase [chips]
|
||||
d_rem_code_phase_chips = d_rem_code_phase_samples * (d_code_freq_chips / static_cast<double>(d_fs_in));
|
||||
d_rem_carrier_phase_rad = fmod(d_rem_carrier_phase_rad + d_carrier_phase_step_rad * static_cast<double>(d_correlation_length_samples), GLONASS_TWO_PI);
|
||||
|
||||
// UPDATE ACCUMULATED CARRIER PHASE
|
||||
CORRECTED_INTEGRATION_TIME_S = (static_cast<double>(d_correlation_length_samples) / static_cast<double>(d_fs_in));
|
||||
d_acc_carrier_phase_cycles -= d_carrier_phase_step_rad * d_correlation_length_samples / GLONASS_TWO_PI;
|
||||
|
||||
// disable tracking loop and inform telemetry decoder
|
||||
enable_dll_pll = false;
|
||||
}
|
||||
else
|
||||
{
|
||||
// perform basic (1ms) correlation
|
||||
// UPDATE INTEGRATION TIME
|
||||
CURRENT_INTEGRATION_TIME_S = static_cast<double>(d_correlation_length_samples) / static_cast<double>(d_fs_in);
|
||||
enable_dll_pll = true;
|
||||
}
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
// UPDATE INTEGRATION TIME
|
||||
CURRENT_INTEGRATION_TIME_S = static_cast<double>(d_correlation_length_samples) / static_cast<double>(d_fs_in);
|
||||
enable_dll_pll = true;
|
||||
}
|
||||
|
||||
if (enable_dll_pll == true)
|
||||
{
|
||||
// ################## PLL ##########################################################
|
||||
// Update PLL discriminator [rads/Ti -> Secs/Ti]
|
||||
d_carr_phase_error_secs_Ti = pll_cloop_two_quadrant_atan(std::complex<float>(d_correlator_outs_16sc[1].real(),d_correlator_outs_16sc[1].imag())) / GLONASS_TWO_PI; //prompt output
|
||||
|
||||
// Carrier discriminator filter
|
||||
// NOTICE: The carrier loop filter includes the Carrier Doppler accumulator, as described in Kaplan
|
||||
// Input [s/Ti] -> output [Hz]
|
||||
d_carrier_doppler_hz = d_carrier_loop_filter.get_carrier_error(0.0, d_carr_phase_error_secs_Ti, CURRENT_INTEGRATION_TIME_S);
|
||||
// PLL to DLL assistance [Secs/Ti]
|
||||
d_pll_to_dll_assist_secs_Ti = (d_carrier_doppler_hz * CURRENT_INTEGRATION_TIME_S) / d_glonass_freq_ch;
|
||||
// code Doppler frequency update
|
||||
d_code_freq_chips = GLONASS_L1_CA_CODE_RATE_HZ + ((d_carrier_doppler_hz * GLONASS_L1_CA_CODE_RATE_HZ) / d_glonass_freq_ch);
|
||||
|
||||
// ################## DLL ##########################################################
|
||||
// DLL discriminator
|
||||
d_code_error_chips_Ti = dll_nc_e_minus_l_normalized(std::complex<float>(d_correlator_outs_16sc[0].real(),d_correlator_outs_16sc[0].imag()), std::complex<float>(d_correlator_outs_16sc[2].real(),d_correlator_outs_16sc[2].imag())); // [chips/Ti] //early and late
|
||||
// Code discriminator filter
|
||||
d_code_error_filt_chips_s = d_code_loop_filter.get_code_nco(d_code_error_chips_Ti); // input [chips/Ti] -> output [chips/second]
|
||||
d_code_error_filt_chips_Ti = d_code_error_filt_chips_s * CURRENT_INTEGRATION_TIME_S;
|
||||
code_error_filt_secs_Ti = d_code_error_filt_chips_Ti / d_code_freq_chips; // [s/Ti]
|
||||
|
||||
// ################## CARRIER AND CODE NCO BUFFER ALIGNEMENT #######################
|
||||
// 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
|
||||
double T_chip_seconds = 1.0 / d_code_freq_chips;
|
||||
double T_prn_seconds = T_chip_seconds * GLONASS_L1_CA_CODE_LENGTH_CHIPS;
|
||||
double T_prn_samples = T_prn_seconds * static_cast<double>(d_fs_in);
|
||||
double K_prn_samples = round(T_prn_samples);
|
||||
double K_T_prn_error_samples = K_prn_samples - T_prn_samples;
|
||||
|
||||
d_rem_code_phase_samples = d_rem_code_phase_samples - K_T_prn_error_samples + code_error_filt_secs_Ti * static_cast<double>(d_fs_in); //(code_error_filt_secs_Ti + d_pll_to_dll_assist_secs_Ti) * static_cast<double>(d_fs_in);
|
||||
d_rem_code_phase_integer_samples = round(d_rem_code_phase_samples); // round to a discrete number of samples
|
||||
d_correlation_length_samples = K_prn_samples + d_rem_code_phase_integer_samples;
|
||||
d_rem_code_phase_samples = d_rem_code_phase_samples - d_rem_code_phase_integer_samples;
|
||||
|
||||
//################### PLL COMMANDS #################################################
|
||||
//carrier phase step (NCO phase increment per sample) [rads/sample]
|
||||
d_carrier_phase_step_rad = GLONASS_TWO_PI * d_carrier_doppler_hz / static_cast<double>(d_fs_in);
|
||||
d_acc_carrier_phase_cycles -= d_carrier_phase_step_rad * d_correlation_length_samples / GLONASS_TWO_PI;
|
||||
// UPDATE ACCUMULATED CARRIER PHASE
|
||||
CORRECTED_INTEGRATION_TIME_S = (static_cast<double>(d_correlation_length_samples) / static_cast<double>(d_fs_in));
|
||||
//remnant carrier phase [rad]
|
||||
d_rem_carrier_phase_rad = fmod(d_rem_carrier_phase_rad + GLONASS_TWO_PI * d_carrier_doppler_hz * CORRECTED_INTEGRATION_TIME_S, GLONASS_TWO_PI);
|
||||
|
||||
//################### DLL COMMANDS #################################################
|
||||
//code phase step (Code resampler phase increment per sample) [chips/sample]
|
||||
d_code_phase_step_chips = d_code_freq_chips / static_cast<double>(d_fs_in);
|
||||
//remnant code phase [chips]
|
||||
d_rem_code_phase_chips = d_rem_code_phase_samples * (d_code_freq_chips / static_cast<double>(d_fs_in));
|
||||
|
||||
// ####### CN0 ESTIMATION AND LOCK DETECTORS #######################################
|
||||
if (d_cn0_estimation_counter < CN0_ESTIMATION_SAMPLES)
|
||||
{
|
||||
// fill buffer with prompt correlator output values
|
||||
d_Prompt_buffer[d_cn0_estimation_counter] = lv_cmake(static_cast<float>(d_correlator_outs_16sc[1].real()), static_cast<float>(d_correlator_outs_16sc[1].imag()) ); // prompt
|
||||
d_cn0_estimation_counter++;
|
||||
}
|
||||
else
|
||||
{
|
||||
d_cn0_estimation_counter = 0;
|
||||
// Code lock indicator
|
||||
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, d_fs_in, GLONASS_L1_CA_CODE_LENGTH_CHIPS);
|
||||
// Carrier lock indicator
|
||||
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES);
|
||||
// Loss of lock detection
|
||||
if (d_carrier_lock_test < d_carrier_lock_threshold or d_CN0_SNV_dB_Hz < MINIMUM_VALID_CN0)
|
||||
{
|
||||
d_carrier_lock_fail_counter++;
|
||||
}
|
||||
else
|
||||
{
|
||||
if (d_carrier_lock_fail_counter > 0) d_carrier_lock_fail_counter--;
|
||||
}
|
||||
if (d_carrier_lock_fail_counter > MAXIMUM_LOCK_FAIL_COUNTER)
|
||||
{
|
||||
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;
|
||||
d_enable_tracking = false; // TODO: check if disabling tracking is consistent with the channel state machine
|
||||
}
|
||||
}
|
||||
// ########### Output the tracking data to navigation and PVT ##########
|
||||
current_synchro_data.Prompt_I = static_cast<double>((d_correlator_outs_16sc[1]).real());
|
||||
current_synchro_data.Prompt_Q = static_cast<double>((d_correlator_outs_16sc[1]).imag());
|
||||
// Tracking_timestamp_secs is aligned with the CURRENT PRN start sample (Hybridization OK!)
|
||||
current_synchro_data.Tracking_sample_counter = d_sample_counter + d_correlation_length_samples;
|
||||
current_synchro_data.Code_phase_samples = d_rem_code_phase_samples;
|
||||
current_synchro_data.Carrier_phase_rads = GLONASS_TWO_PI * d_acc_carrier_phase_cycles;
|
||||
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;
|
||||
if (d_preamble_synchronized == true)
|
||||
{
|
||||
current_synchro_data.correlation_length_ms = d_extend_correlation_ms;
|
||||
}
|
||||
else
|
||||
{
|
||||
current_synchro_data.correlation_length_ms = 1;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
current_synchro_data.Prompt_I = static_cast<double>((d_correlator_outs_16sc[1]).real());
|
||||
current_synchro_data.Prompt_Q = static_cast<double>((d_correlator_outs_16sc[1]).imag());
|
||||
current_synchro_data.Tracking_sample_counter = d_sample_counter + d_correlation_length_samples;
|
||||
current_synchro_data.Code_phase_samples = d_rem_code_phase_samples;
|
||||
current_synchro_data.Carrier_phase_rads = GLONASS_TWO_PI * d_acc_carrier_phase_cycles;
|
||||
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;// todo: project the carrier doppler
|
||||
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
for (int n = 0; n < d_n_correlator_taps; n++)
|
||||
{
|
||||
d_correlator_outs_16sc[n] = lv_cmake(0,0);
|
||||
}
|
||||
|
||||
current_synchro_data.System = {'R'};
|
||||
current_synchro_data.Tracking_sample_counter = d_sample_counter + d_correlation_length_samples;
|
||||
}
|
||||
current_synchro_data.fs=d_fs_in;
|
||||
*out[0] = current_synchro_data;
|
||||
if(d_dump)
|
||||
{
|
||||
// MULTIPLEXED FILE RECORDING - Record results to file
|
||||
float prompt_I;
|
||||
float prompt_Q;
|
||||
float tmp_E, tmp_P, tmp_L;
|
||||
double tmp_double;
|
||||
prompt_I = d_correlator_outs_16sc[1].real();
|
||||
prompt_Q = d_correlator_outs_16sc[1].imag();
|
||||
tmp_E = std::abs<float>(std::complex<float>(d_correlator_outs_16sc[0].real(),d_correlator_outs_16sc[0].imag()));
|
||||
tmp_P = std::abs<float>(std::complex<float>(d_correlator_outs_16sc[1].real(),d_correlator_outs_16sc[1].imag()));
|
||||
tmp_L = std::abs<float>(std::complex<float>(d_correlator_outs_16sc[2].real(),d_correlator_outs_16sc[2].imag()));
|
||||
try
|
||||
{
|
||||
// EPR
|
||||
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));
|
||||
// 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_float=(float)d_sample_counter;
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_sample_counter), sizeof(unsigned long int));
|
||||
// accumulated carrier phase
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_acc_carrier_phase_cycles), sizeof(double));
|
||||
|
||||
// carrier and code frequency
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_carrier_doppler_hz), sizeof(double));
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_code_freq_chips), sizeof(double));
|
||||
|
||||
//PLL commands
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_carr_phase_error_secs_Ti), sizeof(double));
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_carrier_doppler_hz), sizeof(double));
|
||||
|
||||
//DLL commands
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_code_error_chips_Ti), sizeof(double));
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_code_error_filt_chips_Ti), sizeof(double));
|
||||
|
||||
// CN0 and carrier lock test
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_CN0_SNV_dB_Hz), sizeof(double));
|
||||
d_dump_file.write(reinterpret_cast<char*>(&d_carrier_lock_test), sizeof(double));
|
||||
|
||||
// AUX vars (for debug purposes)
|
||||
tmp_double = d_code_error_chips_Ti * CURRENT_INTEGRATION_TIME_S;
|
||||
d_dump_file.write(reinterpret_cast<char*>(&tmp_double), sizeof(double));
|
||||
tmp_double = static_cast<double>(d_sample_counter + d_correlation_length_samples);
|
||||
d_dump_file.write(reinterpret_cast<char*>(&tmp_double), sizeof(double));
|
||||
|
||||
// PRN
|
||||
unsigned int prn_ = d_acquisition_gnss_synchro->PRN;
|
||||
d_dump_file.write(reinterpret_cast<char*>(&prn_), sizeof(unsigned int));
|
||||
}
|
||||
catch (const std::ifstream::failure* e)
|
||||
{
|
||||
LOG(WARNING) << "Exception writing trk dump file " << e->what();
|
||||
}
|
||||
}
|
||||
|
||||
consume_each(d_correlation_length_samples); // this is necessary in gr::block derivates
|
||||
d_sample_counter += d_correlation_length_samples; //count for the processed samples
|
||||
|
||||
return 1; //output tracking result ALWAYS even in the case of d_enable_tracking==false
|
||||
}
|
||||
|
||||
|
||||
void glonass_l1_ca_dll_pll_c_aid_tracking_sc::set_channel(unsigned int channel)
|
||||
{
|
||||
d_channel = channel;
|
||||
LOG(INFO) << "Tracking Channel set to " << d_channel;
|
||||
// ############# ENABLE DATA FILE LOG #################
|
||||
if (d_dump == true)
|
||||
{
|
||||
if (d_dump_file.is_open() == false)
|
||||
{
|
||||
try
|
||||
{
|
||||
d_dump_filename.append(boost::lexical_cast<std::string>(d_channel));
|
||||
d_dump_filename.append(".dat");
|
||||
d_dump_file.exceptions (std::ifstream::failbit | std::ifstream::badbit);
|
||||
d_dump_file.open(d_dump_filename.c_str(), std::ios::out | std::ios::binary);
|
||||
LOG(INFO) << "Tracking dump enabled on channel " << d_channel << " Log file: " << d_dump_filename.c_str() << std::endl;
|
||||
}
|
||||
catch (const std::ifstream::failure* e)
|
||||
{
|
||||
LOG(WARNING) << "channel " << d_channel << " Exception opening trk dump file " << e->what() << std::endl;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
void glonass_l1_ca_dll_pll_c_aid_tracking_sc::set_gnss_synchro(Gnss_Synchro* p_gnss_synchro)
|
||||
{
|
||||
d_acquisition_gnss_synchro = p_gnss_synchro;
|
||||
}
|
||||
@ -0,0 +1,170 @@
|
||||
#ifndef GNSS_SDR_GLONASS_L1_CA_DLL_PLL_C_AID_TRACKING_SC_H
|
||||
#define GNSS_SDR_GLONASS_L1_CA_DLL_PLL_C_AID_TRACKING_SC_H
|
||||
|
||||
#include <fstream>
|
||||
#include <map>
|
||||
#include <string>
|
||||
#include <boost/thread/mutex.hpp>
|
||||
#include <boost/thread/thread.hpp>
|
||||
#include <gnuradio/block.h>
|
||||
#include <volk/volk.h>
|
||||
#include "glonass_l1_signal_processing.h"
|
||||
#include "gnss_synchro.h"
|
||||
#include "tracking_2nd_DLL_filter.h"
|
||||
#include "tracking_FLL_PLL_filter.h"
|
||||
#include "cpu_multicorrelator_16sc.h"
|
||||
|
||||
class glonass_l1_ca_dll_pll_c_aid_tracking_sc;
|
||||
|
||||
typedef boost::shared_ptr<glonass_l1_ca_dll_pll_c_aid_tracking_sc>
|
||||
glonass_l1_ca_dll_pll_c_aid_tracking_sc_sptr;
|
||||
|
||||
glonass_l1_ca_dll_pll_c_aid_tracking_sc_sptr
|
||||
glonass_l1_ca_dll_pll_c_aid_make_tracking_sc(long if_freq,
|
||||
long fs_in, unsigned
|
||||
int vector_length,
|
||||
bool dump,
|
||||
std::string dump_filename,
|
||||
float pll_bw_hz,
|
||||
float dll_bw_hz,
|
||||
float pll_bw_narrow_hz,
|
||||
float dll_bw_narrow_hz,
|
||||
int extend_correlation_ms,
|
||||
float early_late_space_chips);
|
||||
|
||||
|
||||
|
||||
/*!
|
||||
* \brief This class implements a DLL + PLL tracking loop block
|
||||
*/
|
||||
class glonass_l1_ca_dll_pll_c_aid_tracking_sc: public gr::block
|
||||
{
|
||||
public:
|
||||
~glonass_l1_ca_dll_pll_c_aid_tracking_sc();
|
||||
|
||||
void set_channel(unsigned int channel);
|
||||
void set_gnss_synchro(Gnss_Synchro* p_gnss_synchro);
|
||||
void start_tracking();
|
||||
|
||||
int general_work (int noutput_items, gr_vector_int &ninput_items,
|
||||
gr_vector_const_void_star &input_items, gr_vector_void_star &output_items);
|
||||
|
||||
void forecast (int noutput_items, gr_vector_int &ninput_items_required);
|
||||
|
||||
private:
|
||||
friend glonass_l1_ca_dll_pll_c_aid_tracking_sc_sptr
|
||||
glonass_l1_ca_dll_pll_c_aid_make_tracking_sc(long if_freq,
|
||||
long fs_in, unsigned
|
||||
int vector_length,
|
||||
bool dump,
|
||||
std::string dump_filename,
|
||||
float pll_bw_hz,
|
||||
float dll_bw_hz,
|
||||
float pll_bw_narrow_hz,
|
||||
float dll_bw_narrow_hz,
|
||||
int extend_correlation_ms,
|
||||
float early_late_space_chips);
|
||||
|
||||
glonass_l1_ca_dll_pll_c_aid_tracking_sc(long if_freq,
|
||||
long fs_in, unsigned
|
||||
int vector_length,
|
||||
bool dump,
|
||||
std::string dump_filename,
|
||||
float pll_bw_hz,
|
||||
float dll_bw_hz,
|
||||
float pll_bw_narrow_hz,
|
||||
float dll_bw_narrow_hz,
|
||||
int extend_correlation_ms,
|
||||
float early_late_space_chips);
|
||||
|
||||
// tracking configuration vars
|
||||
unsigned int d_vector_length;
|
||||
bool d_dump;
|
||||
|
||||
Gnss_Synchro* d_acquisition_gnss_synchro;
|
||||
unsigned int d_channel;
|
||||
|
||||
long d_if_freq;
|
||||
long d_fs_in;
|
||||
long d_glonass_freq_ch;
|
||||
|
||||
double d_early_late_spc_chips;
|
||||
int d_n_correlator_taps;
|
||||
|
||||
gr_complex* d_ca_code;
|
||||
lv_16sc_t* d_ca_code_16sc;
|
||||
float* d_local_code_shift_chips;
|
||||
//gr_complex* d_correlator_outs;
|
||||
lv_16sc_t* d_correlator_outs_16sc;
|
||||
//cpu_multicorrelator multicorrelator_cpu;
|
||||
cpu_multicorrelator_16sc multicorrelator_cpu_16sc;
|
||||
|
||||
// remaining code phase and carrier phase between tracking loops
|
||||
double d_rem_code_phase_samples;
|
||||
double d_rem_code_phase_chips;
|
||||
double d_rem_carrier_phase_rad;
|
||||
int d_rem_code_phase_integer_samples;
|
||||
|
||||
// PLL and DLL filter library
|
||||
Tracking_2nd_DLL_filter d_code_loop_filter;
|
||||
Tracking_FLL_PLL_filter d_carrier_loop_filter;
|
||||
|
||||
// acquisition
|
||||
double d_acq_code_phase_samples;
|
||||
double d_acq_carrier_doppler_hz;
|
||||
|
||||
// tracking vars
|
||||
float d_dll_bw_hz;
|
||||
float d_pll_bw_hz;
|
||||
float d_dll_bw_narrow_hz;
|
||||
float d_pll_bw_narrow_hz;
|
||||
double d_code_freq_chips;
|
||||
double d_code_phase_step_chips;
|
||||
double d_carrier_doppler_hz;
|
||||
double d_carrier_phase_step_rad;
|
||||
double d_acc_carrier_phase_cycles;
|
||||
double d_code_phase_samples;
|
||||
double d_pll_to_dll_assist_secs_Ti;
|
||||
double d_carr_phase_error_secs_Ti;
|
||||
double d_code_error_chips_Ti;
|
||||
double d_preamble_timestamp_s;
|
||||
int d_extend_correlation_ms;
|
||||
bool d_enable_extended_integration;
|
||||
bool d_preamble_synchronized;
|
||||
double d_code_error_filt_chips_s;
|
||||
double d_code_error_filt_chips_Ti;
|
||||
void msg_handler_preamble_index(pmt::pmt_t msg);
|
||||
|
||||
// symbol history to detect bit transition
|
||||
std::deque<lv_16sc_t> d_E_history;
|
||||
std::deque<lv_16sc_t> d_P_history;
|
||||
std::deque<lv_16sc_t> d_L_history;
|
||||
|
||||
//Integration period in samples
|
||||
int d_correlation_length_samples;
|
||||
|
||||
//processing samples counters
|
||||
unsigned long int d_sample_counter;
|
||||
unsigned long int d_acq_sample_stamp;
|
||||
|
||||
// CN0 estimation and lock detector
|
||||
int d_cn0_estimation_counter;
|
||||
gr_complex* d_Prompt_buffer;
|
||||
double d_carrier_lock_test;
|
||||
double d_CN0_SNV_dB_Hz;
|
||||
double d_carrier_lock_threshold;
|
||||
int d_carrier_lock_fail_counter;
|
||||
|
||||
// control vars
|
||||
bool d_enable_tracking;
|
||||
bool d_pull_in;
|
||||
|
||||
// file dump
|
||||
std::string d_dump_filename;
|
||||
std::ofstream d_dump_file;
|
||||
|
||||
std::map<std::string, std::string> systemName;
|
||||
std::string sys;
|
||||
};
|
||||
|
||||
#endif //GNSS_SDR_GLONASS_L1_CA_DLL_PLL_C_AID_TRACKING_SC_H
|
||||
Loading…
Reference in New Issue
Block a user