/*! * \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) 2010-2012 (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 . * * ------------------------------------------------------------------------- */ #include "gnss_synchro.h" #include "galileo_e1_tcp_connector_tracking_cc.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 #include #include #include #include "math.h" #include #include #include #include #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, gr_msg_queue_sptr 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) { 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, gr_msg_queue_sptr 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): gr_block ("Galileo_E1_Tcp_Connector_Tracking_cc", gr_make_io_signature (1, 1, sizeof(gr_complex)), gr_make_io_signature(1, 1, sizeof(Gnss_Synchro))) { 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; d_code_loop_filter=Tracking_2nd_DLL_filter(0.004); d_carrier_loop_filter=Tracking_2nd_PLL_filter(0.004); // Initialize tracking ========================================== d_code_loop_filter.set_DLL_BW(dll_bw_hz); d_carrier_loop_filter.set_PLL_BW(pll_bw_hz); //--- 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 // int d_ca_code_size = (int)(2*Galileo_E1_B_CODE_LENGTH_CHIPS + 4); d_ca_code = new gr_complex[(int)(2*Galileo_E1_B_CODE_LENGTH_CHIPS + 4)]; // std::cout << "d_ca_code_size = " << d_ca_code_size << std::endl; /* If an array is partitioned for more than one thread to operate on, * having the sub-array boundaries unaligned to cache lines could lead * to performance degradation. Here we allocate memory * (gr_comlex array of size 2*d_vector_length) aligned to cache of 16 bytes */ // todo: do something if posix_memalign fails // Get space for the resampled early / prompt / late local replicas if (posix_memalign((void**)&d_very_early_code, 16, d_vector_length * sizeof(gr_complex) * 2) == 0){}; if (posix_memalign((void**)&d_early_code, 16, d_vector_length * sizeof(gr_complex) * 2) == 0){}; if (posix_memalign((void**)&d_prompt_code, 16, d_vector_length * sizeof(gr_complex) * 2) == 0){}; if (posix_memalign((void**)&d_late_code, 16, d_vector_length * sizeof(gr_complex) * 2) == 0){}; if (posix_memalign((void**)&d_very_late_code, 16, d_vector_length * sizeof(gr_complex) * 2) == 0){}; // space for carrier wipeoff and signal baseband vectors if (posix_memalign((void**)&d_carr_sign, 16, d_vector_length * sizeof(gr_complex) * 2) == 0){}; // correlator outputs (scalar) if (posix_memalign((void**)&d_Very_Early, 16, sizeof(gr_complex)) == 0){}; if (posix_memalign((void**)&d_Early, 16, sizeof(gr_complex)) == 0){}; if (posix_memalign((void**)&d_Prompt, 16, sizeof(gr_complex)) == 0){}; if (posix_memalign((void**)&d_Late, 16, sizeof(gr_complex)) == 0){}; if (posix_memalign((void**)&d_Very_Late, 16, sizeof(gr_complex)) == 0){}; //--- Perform initializations ------------------------------ // define initial code frequency basis of NCO d_code_freq_hz = 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; // define phase step d_code_phase_step_chips = d_code_freq_hz / (float)d_fs_in; //[chips] // sample synchronization d_sample_counter = 0; //d_sample_counter_seconds = 0; d_acq_sample_stamp = 0; d_enable_tracking = false; d_pull_in = false; d_last_seg = 0; 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["G"] = std::string("GPS"); systemName["R"] = std::string("GLONASS"); systemName["S"] = std::string("SBAS"); systemName["E"] = std::string("Galileo"); systemName["C"] = std::string("Compass"); } 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; // DLL/PLL filter initialization d_carrier_loop_filter.initialize(); //initialize the carrier filter d_code_loop_filter.initialize(); //initialize the code filter // generate local reference ALWAYS starting at chip 2 (2 samples per chip) galileo_e1_code_gen_complex_sampled(&d_ca_code[2],d_acquisition_gnss_synchro->Signal, false, d_acquisition_gnss_synchro->PRN, 2*Galileo_E1_CODE_CHIP_RATE_HZ, 0); d_ca_code[0] = d_ca_code[(int)(2*Galileo_E1_B_CODE_LENGTH_CHIPS)]; d_ca_code[1] = d_ca_code[(int)(2*Galileo_E1_B_CODE_LENGTH_CHIPS+1)]; d_ca_code[(int)(2*Galileo_E1_B_CODE_LENGTH_CHIPS+2)] = d_ca_code[2]; d_ca_code[(int)(2*Galileo_E1_B_CODE_LENGTH_CHIPS+3)] = d_ca_code[3]; d_carrier_lock_fail_counter = 0; d_rem_code_phase_samples = 0.0; d_rem_carr_phase_rad = 0; d_next_rem_code_phase_samples = 0; d_acc_carrier_phase_rad = 0; d_code_phase_samples = d_acq_code_phase_samples; d_carrier_doppler_hz = d_acq_carrier_doppler_hz; d_next_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; DLOG(INFO) << "Start tracking for satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << " received" << std::endl; // enable tracking d_pull_in = true; d_enable_tracking = true; std::cout << "PULL-IN Doppler [Hz]=" << d_carrier_doppler_hz << " PULL-IN Code Phase [samples]=" << d_acq_code_phase_samples << std::endl; } void Galileo_E1_Tcp_Connector_Tracking_cc::update_local_code() { double tcode_half_chips; float rem_code_phase_half_chips; int associated_chip_index; int code_length_half_chips = (int)(2*Galileo_E1_B_CODE_LENGTH_CHIPS); double code_phase_step_chips; double code_phase_step_half_chips; int early_late_spc_samples; int very_early_late_spc_samples; int epl_loop_length_samples; // unified loop for E, P, L code vectors code_phase_step_chips = ((double)d_code_freq_hz) / ((double)d_fs_in); code_phase_step_half_chips = (2.0*(double)d_code_freq_hz) / ((double)d_fs_in); rem_code_phase_half_chips = d_rem_code_phase_samples * (2*d_code_freq_hz / d_fs_in); tcode_half_chips = -(double)rem_code_phase_half_chips; early_late_spc_samples=round(d_early_late_spc_chips/code_phase_step_chips); very_early_late_spc_samples=round(d_very_early_late_spc_chips/code_phase_step_chips); epl_loop_length_samples=d_current_prn_length_samples+very_early_late_spc_samples*2; for (int i=0; itelemetry_decoder Gnss_Synchro current_synchro_data; // Fill the acquisition data current_synchro_data = *d_acquisition_gnss_synchro; const gr_complex* in = (gr_complex*) input_items[0]; //PRN start block alignement Gnss_Synchro **out = (Gnss_Synchro **) &output_items[0]; // Update the prn length based on code freq (variable) and // sampling frequency (fixed) // variable code PRN sample block size d_current_prn_length_samples = d_next_prn_length_samples; update_local_code(); update_local_carrier(); // perform Early, Prompt and Late correlation d_correlator.Carrier_wipeoff_and_VEPL_volk(d_current_prn_length_samples, in, d_carr_sign, d_very_early_code, d_early_code, d_prompt_code, d_late_code, d_very_late_code, d_Very_Early, d_Early, d_Prompt, d_Late, d_Very_Late, is_unaligned()); //! Variable used for control d_control_id++; //! Send and receive a TCP packet boost::array 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 discriminator, carrier loop filter implementation and NCO command generation (TCP_connector) carr_nco_hz = tcp_data.proc_pack_carr_error; // Modify carrier freq based on NCO command (TCP_connector) d_carrier_doppler_hz = tcp_data.proc_pack_carrier_doppler_hz; // DLL discriminator, carrier loop filter implementation and NCO command generation (TCP_connector) code_nco_chips = tcp_data.proc_pack_code_error; // Modify code freq based on NCO command d_code_freq_hz = Galileo_E1_CODE_CHIP_RATE_HZ + (d_carrier_doppler_hz * Galileo_E1_CODE_CHIP_RATE_HZ) / Galileo_E1_FREQ_HZ - code_nco_chips; // Update the phase step based on code freq (variable) and sampling frequency (fixed) d_code_phase_step_chips = d_code_freq_hz / (float)d_fs_in; //[chips] // keep alignment parameters for the next input buffer float T_chip_seconds; float T_prn_seconds; float T_prn_samples; float K_blk_samples; T_chip_seconds = 1 / d_code_freq_hz; T_prn_seconds = T_chip_seconds * Galileo_E1_B_CODE_LENGTH_CHIPS; T_prn_samples = T_prn_seconds * d_fs_in; d_rem_code_phase_samples = d_next_rem_code_phase_samples; K_blk_samples = T_prn_samples + d_rem_code_phase_samples; d_next_prn_length_samples = round(K_blk_samples); //round to a discrete samples d_next_rem_code_phase_samples = K_blk_samples - d_next_prn_length_samples; //rounding error /*! * \todo Improve the lock detection algorithm! */ // ####### 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; d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, d_fs_in, Galileo_E1_B_CODE_LENGTH_CHIPS); d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES); // ###### TRACKING UNLOCK NOTIFICATION ##### 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 << "Channel " << d_channel << " loss of lock!" << std::endl ; //tracking_message = 3; //loss of lock //d_channel_internal_queue->push(tracking_message); ControlMessageFactory* cmf = new ControlMessageFactory(); if (d_queue != gr_msg_queue_sptr()) { d_queue->handle(cmf->GetQueueMessage(d_channel, 2)); } delete cmf; 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; // 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.CN0_dB_hz = (double)d_CN0_SNV_dB_Hz; *out[0] = current_synchro_data; // ########## DEBUG OUTPUT /*! * \todo The stop timer has to be moved to the signal source! */ // debug: Second counter in channel 0 if (d_channel == 0) { if (floor(d_sample_counter / d_fs_in) != d_last_seg) { d_last_seg = floor(d_sample_counter / d_fs_in); std::cout << "Current input signal time = " << d_last_seg << " [s]" << std::endl; std::cout << "Tracking CH " << d_channel << ": Satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << ", CN0 = " << d_CN0_SNV_dB_Hz << " [dB-Hz]" << std::endl; } } else { if (floor(d_sample_counter / d_fs_in) != d_last_seg) { d_last_seg = floor(d_sample_counter / d_fs_in); std::cout << "Tracking CH " << d_channel << ": Satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << ", CN0 = " << d_CN0_SNV_dB_Hz << " [dB-Hz]" << std::endl; } } } else { *d_Early = gr_complex(0,0); *d_Prompt = gr_complex(0,0); *d_Late = gr_complex(0,0); Gnss_Synchro **out = (Gnss_Synchro **) &output_items[0]; //block output streams pointer // GNSS_SYNCHRO OBJECT to interchange data between tracking->telemetry_decoder Gnss_Synchro current_synchro_data; *out[0] = current_synchro_data; //! When tracking is disabled an array of 1's is sent to maintain the TCP connection boost::array 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); } 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(*d_Very_Early); tmp_E = std::abs(*d_Early); tmp_P = std::abs(*d_Prompt); tmp_L = std::abs(*d_Late); tmp_VL = std::abs(*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_hz, sizeof(float)); //PLL commands d_dump_file.write((char*)&tmp_float, sizeof(float)); d_dump_file.write((char*)&carr_nco_hz, sizeof(float)); //DLL commands d_dump_file.write((char*)&tmp_float, sizeof(float)); d_dump_file.write((char*)&code_nco_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 (std::ifstream::failure e) { std::cout << "Exception writing trk dump file " << e.what() << std::endl; } } // if(d_current_prn_length_samples!=d_vector_length) // std::cout << "d_current_prn_length_samples = " << d_current_prn_length_samples << std::endl; consume_each(d_current_prn_length_samples); // this is necesary 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_AT_LEVEL(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(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); std::cout << "Tracking dump enabled on channel " << d_channel << " Log file: " << d_dump_filename.c_str() << std::endl; } catch (std::ifstream::failure e) { std::cout << "channel " << d_channel << " Exception opening trk dump file " << e.what() << std::endl; } } } //! 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_channel_queue(concurrent_queue *channel_internal_queue) { d_channel_internal_queue = channel_internal_queue; } void Galileo_E1_Tcp_Connector_Tracking_cc::set_gnss_synchro(Gnss_Synchro* p_gnss_synchro) { d_acquisition_gnss_synchro = p_gnss_synchro; // Gnss_Satellite(satellite.get_system(), satellite.get_PRN()); //DLOG(INFO) << "Tracking code phase set to " << d_acq_code_phase_samples; //DLOG(INFO) << "Tracking carrier doppler set to " << d_acq_carrier_doppler_hz; //DLOG(INFO) << "Tracking Satellite set to " << d_satellite; }