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gnss-sdr/src/algorithms/tracking/gnuradio_blocks/galileo_e1_tcp_connector_tr...

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/*!
* \file galileo_e1_tcp_connector_tracking_cc.cc
* \brief Implementation of a TCP connector block based on Code DLL + carrier PLL
* \author David Pubill, 2012. dpubill(at)cttc.es
* Luis Esteve, 2012. luis(at)epsilon-formacion.com
* Javier Arribas, 2011. jarribas(at)cttc.es
*
*
* Code DLL + carrier PLL according to the algorithms described in:
* [1] K.Borre, D.M.Akos, N.Bertelsen, P.Rinder, and S.H.Jensen,
* A Software-Defined GPS and Galileo Receiver. A Single-Frequency
* Approach, Birkha user, 2007
*
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2015 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
*
* This file is part of GNSS-SDR.
*
* GNSS-SDR is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GNSS-SDR is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#include "galileo_e1_tcp_connector_tracking_cc.h"
#include <cmath>
#include <iostream>
#include <memory>
#include <sstream>
#include <boost/asio.hpp>
#include <boost/lexical_cast.hpp>
#include <gnuradio/io_signature.h>
#include <glog/logging.h>
#include <volk/volk.h>
#include "galileo_e1_signal_processing.h"
#include "tracking_discriminators.h"
#include "lock_detectors.h"
#include "GPS_L1_CA.h"
#include "Galileo_E1.h"
#include "control_message_factory.h"
#include "tcp_communication.h"
#include "tcp_packet_data.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;
galileo_e1_tcp_connector_tracking_cc_sptr galileo_e1_tcp_connector_make_tracking_cc(
long if_freq,
long fs_in,
unsigned int vector_length,
boost::shared_ptr<gr::msg_queue> queue,
bool dump,
std::string dump_filename,
float pll_bw_hz,
float dll_bw_hz,
float early_late_space_chips,
float very_early_late_space_chips,
size_t port_ch0)
{
return galileo_e1_tcp_connector_tracking_cc_sptr(new Galileo_E1_Tcp_Connector_Tracking_cc(if_freq,
fs_in, vector_length, queue, dump, dump_filename, pll_bw_hz, dll_bw_hz, early_late_space_chips, very_early_late_space_chips, port_ch0));
}
void Galileo_E1_Tcp_Connector_Tracking_cc::forecast (int noutput_items,
gr_vector_int &ninput_items_required)
{
if (noutput_items != 0)
{
ninput_items_required[0] = (int)d_vector_length*2; // set the required available samples in each call
}
}
Galileo_E1_Tcp_Connector_Tracking_cc::Galileo_E1_Tcp_Connector_Tracking_cc(
long if_freq,
long fs_in,
unsigned int vector_length,
boost::shared_ptr<gr::msg_queue> queue,
bool dump,
std::string dump_filename,
float pll_bw_hz __attribute__((unused)),
float dll_bw_hz __attribute__((unused)),
float early_late_space_chips,
float very_early_late_space_chips,
size_t port_ch0):
gr::block("Galileo_E1_Tcp_Connector_Tracking_cc", gr::io_signature::make(1, 1, sizeof(gr_complex)),
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_relative_rate(1.0/vector_length);
// initialize internal vars
d_queue = queue;
d_dump = dump;
d_if_freq = if_freq;
d_fs_in = fs_in;
d_vector_length = vector_length;
d_dump_filename = dump_filename;
// Initialize tracking ==========================================
//--- DLL variables --------------------------------------------------------
d_early_late_spc_chips = early_late_space_chips; // Define early-late offset (in chips)
d_very_early_late_spc_chips = very_early_late_space_chips; // Define very-early-late offset (in chips)
//--- TCP CONNECTOR variables --------------------------------------------------------
d_port_ch0 = port_ch0;
d_port = 0;
d_listen_connection = true;
d_control_id = 0;
// Initialization of local code replica
// Get space for a vector with the sinboc(1,1) replica sampled 2x/chip
d_ca_code = static_cast<gr_complex*>(volk_malloc((2*Galileo_E1_B_CODE_LENGTH_CHIPS) * sizeof(gr_complex), volk_get_alignment()));
// correlator outputs (scalar)
d_n_correlator_taps = 5; // Very-Early, Early, Prompt, Late, Very-Late
d_correlator_outs = static_cast<gr_complex*>(volk_malloc(d_n_correlator_taps*sizeof(gr_complex), volk_get_alignment()));
for (int n = 0; n < d_n_correlator_taps; n++)
{
d_correlator_outs[n] = gr_complex(0,0);
}
// map memory pointers of correlator outputs
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 = static_cast<float*>(volk_malloc(d_n_correlator_taps * sizeof(float), volk_get_alignment()));
// Set TAPs delay values [chips]
d_local_code_shift_chips[0] = - d_very_early_late_spc_chips * 2.0;
d_local_code_shift_chips[1] = - d_very_early_late_spc_chips;
d_local_code_shift_chips[2] = 0.0;
d_local_code_shift_chips[3] = d_very_early_late_spc_chips;
d_local_code_shift_chips[4] = d_very_early_late_spc_chips * 2.0;
d_correlation_length_samples = d_vector_length;
multicorrelator_cpu.init(2 * d_correlation_length_samples, d_n_correlator_taps);
//--- Perform initializations ------------------------------
// define initial code frequency basis of NCO
d_code_freq_chips = Galileo_E1_CODE_CHIP_RATE_HZ;
// define residual code phase (in chips)
d_rem_code_phase_samples = 0.0;
// define residual carrier phase
d_rem_carr_phase_rad = 0.0;
// sample synchronization
d_sample_counter = 0;
d_acq_sample_stamp = 0;
d_enable_tracking = false;
d_pull_in = false;
d_current_prn_length_samples = (int)d_vector_length;
// 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["E"] = std::string("Galileo");
d_acquisition_gnss_synchro = 0;
d_channel = 0;
d_next_rem_code_phase_samples = 0;
d_acq_code_phase_samples = 0.0;
d_acq_carrier_doppler_hz = 0.0;
d_acc_carrier_phase_rad = 0.0;
d_acc_code_phase_secs = 0.0;
d_code_phase_samples = 0;
d_next_prn_length_samples = 0;
d_carrier_doppler_hz = 0.0;
}
void Galileo_E1_Tcp_Connector_Tracking_cc::start_tracking()
{
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;
// generate local reference ALWAYS starting at chip 1 (2 samples per chip)
galileo_e1_code_gen_complex_sampled(d_ca_code,
d_acquisition_gnss_synchro->Signal,
false,
d_acquisition_gnss_synchro->PRN,
2 * Galileo_E1_CODE_CHIP_RATE_HZ,
0);
multicorrelator_cpu.set_local_code_and_taps(static_cast<int>(2*Galileo_E1_B_CODE_LENGTH_CHIPS), d_ca_code, d_local_code_shift_chips);
for (int n = 0; n < d_n_correlator_taps; n++)
{
d_correlator_outs[n] = gr_complex(0,0);
}
d_carrier_lock_fail_counter = 0;
d_rem_code_phase_samples = 0.0;
d_rem_carr_phase_rad = 0;
d_acc_carrier_phase_rad = 0;
d_acc_code_phase_secs = 0;
d_carrier_doppler_hz = d_acq_carrier_doppler_hz;
d_current_prn_length_samples = d_vector_length;
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;
LOG(INFO) << "PULL-IN Doppler [Hz]=" << d_carrier_doppler_hz << " PULL-IN Code Phase [samples]=" << d_acq_code_phase_samples;
}
Galileo_E1_Tcp_Connector_Tracking_cc::~Galileo_E1_Tcp_Connector_Tracking_cc()
{
d_dump_file.close();
delete[] d_Prompt_buffer;
volk_free(d_ca_code);
volk_free(d_local_code_shift_chips);
volk_free(d_correlator_outs);
d_tcp_com.close_tcp_connection(d_port);
multicorrelator_cpu.free();
}
int Galileo_E1_Tcp_Connector_Tracking_cc::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)
{
// process vars
float carr_error_filt_hz;
float code_error_filt_chips;
tcp_packet_data tcp_data;
// GNSS_SYNCHRO OBJECT to interchange data between tracking->telemetry_decoder
Gnss_Synchro current_synchro_data = Gnss_Synchro();
// Block input data and block output stream pointers
const gr_complex* in = (gr_complex*) input_items[0];
Gnss_Synchro **out = (Gnss_Synchro **) &output_items[0];
if (d_enable_tracking == true)
{
// Fill the acquisition data
current_synchro_data = *d_acquisition_gnss_synchro;
if (d_pull_in == true)
{
/*
* Signal alignment (skip samples until the incoming signal is aligned with local replica)
*/
int samples_offset;
float 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_current_prn_length_samples - fmod((float)acq_to_trk_delay_samples, (float)d_current_prn_length_samples);
samples_offset = round(d_acq_code_phase_samples + acq_trk_shif_correction_samples);
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter) + static_cast<double>(d_rem_code_phase_samples)) / static_cast<double>(d_fs_in);
*out[0] = current_synchro_data;
d_sample_counter = d_sample_counter + samples_offset; //count for the processed samples
d_pull_in = false;
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.set_input_output_vectors(d_correlator_outs,in);
double carr_phase_step_rad = GALILEO_TWO_PI * d_carrier_doppler_hz / static_cast<double>(d_fs_in);
double code_phase_step_half_chips = (2.0 * d_code_freq_chips) / (static_cast<double>(d_fs_in));
double rem_code_phase_half_chips = d_rem_code_phase_samples * (2.0*d_code_freq_chips / d_fs_in);
multicorrelator_cpu.Carrier_wipeoff_multicorrelator_resampler(
d_rem_carr_phase_rad,
carr_phase_step_rad,
rem_code_phase_half_chips,
code_phase_step_half_chips,
d_correlation_length_samples);
// ################## TCP CONNECTOR ##########################################################
//! Variable used for control
d_control_id++;
//! Send and receive a TCP packet
boost::array<float, NUM_TX_VARIABLES_GALILEO_E1> tx_variables_array = {{d_control_id,
(*d_Very_Early).real(),
(*d_Very_Early).imag(),
(*d_Early).real(),
(*d_Early).imag(),
(*d_Late).real(),
(*d_Late).imag(),
(*d_Very_Late).real(),
(*d_Very_Late).imag(),
(*d_Prompt).real(),
(*d_Prompt).imag(),
d_acq_carrier_doppler_hz,
1}};
d_tcp_com.send_receive_tcp_packet_galileo_e1(tx_variables_array, &tcp_data);
// ################## PLL ##########################################################
// PLL discriminator, carrier loop filter implementation and NCO command generation (TCP_connector)
carr_error_filt_hz = tcp_data.proc_pack_carr_error;
// New carrier Doppler frequency estimation
d_carrier_doppler_hz = d_acq_carrier_doppler_hz + carr_error_filt_hz;
// New code Doppler frequency estimation
d_code_freq_chips = Galileo_E1_CODE_CHIP_RATE_HZ + ((d_carrier_doppler_hz * Galileo_E1_CODE_CHIP_RATE_HZ) / Galileo_E1_FREQ_HZ);
//carrier phase accumulator for (K) doppler estimation
d_acc_carrier_phase_rad -= GPS_TWO_PI*d_carrier_doppler_hz*Galileo_E1_CODE_PERIOD;
//remnant carrier phase to prevent overflow in the code NCO
d_rem_carr_phase_rad = d_rem_carr_phase_rad + GPS_TWO_PI*d_carrier_doppler_hz*Galileo_E1_CODE_PERIOD;
d_rem_carr_phase_rad = fmod(d_rem_carr_phase_rad, GPS_TWO_PI);
// ################## DLL ##########################################################
// DLL discriminator, carrier loop filter implementation and NCO command generation (TCP_connector)
code_error_filt_chips = tcp_data.proc_pack_code_error;
//Code phase accumulator
float code_error_filt_secs;
code_error_filt_secs = (Galileo_E1_CODE_PERIOD * code_error_filt_chips) / Galileo_E1_CODE_CHIP_RATE_HZ; //[seconds]
d_acc_code_phase_secs = d_acc_code_phase_secs + code_error_filt_secs;
// ################## CARRIER AND CODE NCO BUFFER ALIGNEMENT #######################
// keep alignment parameters for the next input buffer
double T_chip_seconds;
double T_prn_seconds;
double T_prn_samples;
double K_blk_samples;
// Compute the next buffer lenght based in the new period of the PRN sequence and the code phase error estimation
T_chip_seconds = 1 / (double)d_code_freq_chips;
T_prn_seconds = T_chip_seconds * Galileo_E1_B_CODE_LENGTH_CHIPS;
T_prn_samples = T_prn_seconds * (double)d_fs_in;
K_blk_samples = T_prn_samples + d_rem_code_phase_samples + code_error_filt_secs * (double)d_fs_in;
d_current_prn_length_samples = round(K_blk_samples); //round to a discrete samples
//d_rem_code_phase_samples = K_blk_samples - d_current_prn_length_samples; //rounding error < 1 sample
// ####### 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_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, Galileo_E1_B_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 << "!";
std::unique_ptr<ControlMessageFactory> cmf(new ControlMessageFactory());
if (d_queue != gr::msg_queue::sptr())
{
d_queue->handle(cmf->GetQueueMessage(d_channel, 2));
}
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 = (double)(*d_Prompt).real();
current_synchro_data.Prompt_Q = (double)(*d_Prompt).imag();
// Tracking_timestamp_secs is aligned with the PRN start sample
//current_synchro_data.Tracking_timestamp_secs = ((double)d_sample_counter + (double)d_next_prn_length_samples + (double)d_next_rem_code_phase_samples)/(double)d_fs_in;
current_synchro_data.Tracking_timestamp_secs = ((double)d_sample_counter + (double)d_rem_code_phase_samples)/(double)d_fs_in;
d_rem_code_phase_samples = K_blk_samples - d_current_prn_length_samples; //rounding error < 1 sample
// This tracking block aligns the Tracking_timestamp_secs with the start sample of the PRN, thus, Code_phase_secs=0
current_synchro_data.Code_phase_secs = 0;
current_synchro_data.Carrier_phase_rads = (double)d_acc_carrier_phase_rad;
current_synchro_data.Carrier_Doppler_hz = (double)d_carrier_doppler_hz;
current_synchro_data.CN0_dB_hz = (double)d_CN0_SNV_dB_Hz;
current_synchro_data.Flag_valid_symbol_output = true;
current_synchro_data.correlation_length_ms = 4;
}
else
{
*d_Early = gr_complex(0,0);
*d_Prompt = gr_complex(0,0);
*d_Late = gr_complex(0,0);
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter) + static_cast<double>(d_rem_code_phase_samples)) / static_cast<double>(d_fs_in);
//! When tracking is disabled an array of 1's is sent to maintain the TCP connection
boost::array<float, NUM_TX_VARIABLES_GALILEO_E1> tx_variables_array = {{1,1,1,1,1,1,1,1,1,1,1,1,0}};
d_tcp_com.send_receive_tcp_packet_galileo_e1(tx_variables_array, &tcp_data);
}
//assign the GNURadio block output data
current_synchro_data.System = {'E'};
std::string str_aux = "1B";
const char * str = str_aux.c_str(); // get a C style null terminated string
std::memcpy((void*)current_synchro_data.Signal, str, 3);
*out[0] = current_synchro_data;
if(d_dump)
{
// MULTIPLEXED FILE RECORDING - Record results to file
float prompt_I;
float prompt_Q;
float tmp_VE, tmp_E, tmp_P, tmp_L, tmp_VL;
float tmp_float;
tmp_float = 0;
double tmp_double;
prompt_I = (*d_Prompt).real();
prompt_Q = (*d_Prompt).imag();
tmp_VE = std::abs<float>(*d_Very_Early);
tmp_E = std::abs<float>(*d_Early);
tmp_P = std::abs<float>(*d_Prompt);
tmp_L = std::abs<float>(*d_Late);
tmp_VL = std::abs<float>(*d_Very_Late);
try
{
// EPR
d_dump_file.write((char*)&tmp_VE, sizeof(float));
d_dump_file.write((char*)&tmp_E, sizeof(float));
d_dump_file.write((char*)&tmp_P, sizeof(float));
d_dump_file.write((char*)&tmp_L, sizeof(float));
d_dump_file.write((char*)&tmp_VL, sizeof(float));
// PROMPT I and Q (to analyze navigation symbols)
d_dump_file.write((char*)&prompt_I, sizeof(float));
d_dump_file.write((char*)&prompt_Q, sizeof(float));
// PRN start sample stamp
d_dump_file.write((char*)&d_sample_counter, sizeof(unsigned long int));
// accumulated carrier phase
d_dump_file.write((char*)&d_acc_carrier_phase_rad, sizeof(float));
// carrier and code frequency
d_dump_file.write((char*)&d_carrier_doppler_hz, sizeof(float));
d_dump_file.write((char*)&d_code_freq_chips, sizeof(float));
//PLL commands
d_dump_file.write((char*)&tmp_float, sizeof(float));
d_dump_file.write((char*)&carr_error_filt_hz, sizeof(float));
//DLL commands
d_dump_file.write((char*)&tmp_float, sizeof(float));
d_dump_file.write((char*)&code_error_filt_chips, sizeof(float));
// CN0 and carrier lock test
d_dump_file.write((char*)&d_CN0_SNV_dB_Hz, sizeof(float));
d_dump_file.write((char*)&d_carrier_lock_test, sizeof(float));
// AUX vars (for debug purposes)
tmp_float = d_rem_code_phase_samples;
d_dump_file.write((char*)&tmp_float, sizeof(float));
tmp_double = (double)(d_sample_counter+d_current_prn_length_samples);
d_dump_file.write((char*)&tmp_double, sizeof(double));
}
catch (const std::ifstream::failure &e)
{
LOG(WARNING) << "Exception writing trk dump file " << e.what();
}
}
consume_each(d_current_prn_length_samples); // this is needed in gr::block derivates
d_sample_counter += d_current_prn_length_samples; //count for the processed samples
return 1; //output tracking result ALWAYS even in the case of d_enable_tracking==false
}
void Galileo_E1_Tcp_Connector_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();
}
catch (const std::ifstream::failure &e)
{
LOG(WARNING) << "channel " << d_channel << " Exception opening trk dump file " << e.what();
}
}
}
//! Listen for connections on a TCP port
if (d_listen_connection == true)
{
d_port = d_port_ch0 + d_channel;
d_listen_connection = d_tcp_com.listen_tcp_connection(d_port, d_port_ch0);
}
}
void Galileo_E1_Tcp_Connector_Tracking_cc::set_gnss_synchro(Gnss_Synchro* p_gnss_synchro)
{
d_acquisition_gnss_synchro = p_gnss_synchro;
}
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