mirror of https://github.com/gnss-sdr/gnss-sdr
544 lines
22 KiB
C++
544 lines
22 KiB
C++
/*!
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* \file beidou_b1i_telemetry_decoder_cc.cc
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* \brief Implementation of a NAV message demodulator block based on
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* Kay Borre book MATLAB-based GPS receiver
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* \author Sergi Segura, 2018. sergi.segura.munoz(at)gmail.es
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*
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* -------------------------------------------------------------------------
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*
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* Copyright (C) 2010-2018 (see AUTHORS file for a list of contributors)
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*
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* GNSS-SDR is a software defined Global Navigation
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* Satellite Systems receiver
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*
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* This file is part of GNSS-SDR.
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*
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* GNSS-SDR is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GNSS-SDR is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNSS-SDR. If not, see <https://www.gnu.org/licenses/>.
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*
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* -------------------------------------------------------------------------
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*/
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#include "beidou_b1i_telemetry_decoder_cc.h"
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#include "control_message_factory.h"
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#include <boost/lexical_cast.hpp>
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#include <glog/logging.h>
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#include <gnuradio/io_signature.h>
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#include <volk_gnsssdr/volk_gnsssdr.h>
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using google::LogMessage;
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beidou_b1i_telemetry_decoder_cc_sptr
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beidou_b1i_make_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump)
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{
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return beidou_b1i_telemetry_decoder_cc_sptr(new beidou_b1i_telemetry_decoder_cc(satellite, dump));
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}
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beidou_b1i_telemetry_decoder_cc::beidou_b1i_telemetry_decoder_cc(
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const Gnss_Satellite &satellite,
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bool dump) : gr::block("beidou_navigation_cc", gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)),
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gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)))
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{
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// Ephemeris data port out
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this->message_port_register_out(pmt::mp("telemetry"));
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// initialize internal vars
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d_dump = dump;
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d_satellite = Gnss_Satellite(satellite.get_system(), satellite.get_PRN());
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// set the preamble
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unsigned short int preambles_bits[BEIDOU_B1I_PREAMBLE_LENGTH_BITS] = BEIDOU_PREAMBLE;
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// preamble bits to sampled symbols
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d_preambles_symbols = static_cast<int *>(volk_gnsssdr_malloc(BEIDOU_B1I_PREAMBLE_LENGTH_SYMBOLS * sizeof(int), volk_gnsssdr_get_alignment()));
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int n = 0;
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for (int i = 0; i < BEIDOU_B1I_PREAMBLE_LENGTH_BITS; i++)
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{
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if (preambles_bits[i] == 1)
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{
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d_preambles_symbols[n] = 1;
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}
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else
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{
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d_preambles_symbols[n] = -1;
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}
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n++;
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}
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d_stat = 0;
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d_symbol_accumulator = 0;
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d_symbol_accumulator_counter = 0;
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d_frame_bit_index = 0;
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d_flag_frame_sync = false;
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d_BEIDOU_frame_4bytes = 0;
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d_prev_BEIDOU_frame_4bytes = 0;
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d_flag_parity = false;
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d_TOW_at_Preamble_ms = 0;
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flag_TOW_set = false;
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d_flag_preamble = false;
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d_flag_new_tow_available = false;
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word_number = 0;
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d_channel = 0;
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flag_PLL_180_deg_phase_locked = false;
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d_preamble_time_samples = 0;
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d_TOW_at_current_symbol_ms = 0;
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d_symbol_history.resize(BEIDOU_B1I_PREAMBLE_LENGTH_BITS); // Change fixed buffer size
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d_symbol_nh_history.resize(BEIDOU_B1I_NH_CODE_LENGTH); // Change fixed buffer size
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d_bit_buffer.resize(30); // Change fixed buffer size
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d_symbol_history.clear(); // Clear all the elements in the buffer
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d_symbol_nh_history.clear();
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d_bit_buffer.clear();
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d_make_correlation = true;
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d_symbol_counter_corr = 0;
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for (int aux = 0; aux < BEIDOU_B1I_NH_CODE_LENGTH; aux++)
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{
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if (BEIDOU_B1I_NH_CODE[aux] == 0)
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{
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bits_NH[aux] = -1.0;
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}
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else
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{
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bits_NH[aux] = 1.0;
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}
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}
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sync_NH = false;
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new_sym = false;
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}
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beidou_b1i_telemetry_decoder_cc::~beidou_b1i_telemetry_decoder_cc()
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{
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volk_gnsssdr_free(d_preambles_symbols);
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if (d_dump_file.is_open() == true)
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{
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try
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{
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d_dump_file.close();
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}
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catch (const std::exception &ex)
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{
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LOG(WARNING) << "Exception in destructor closing the dump file " << ex.what();
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}
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}
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}
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void beidou_b1i_telemetry_decoder_cc::set_satellite(const Gnss_Satellite &satellite)
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{
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d_satellite = Gnss_Satellite(satellite.get_system(), satellite.get_PRN());
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DLOG(INFO) << "Setting decoder Finite State Machine to satellite " << d_satellite;
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d_BEIDOU_FSM.i_satellite_PRN = d_satellite.get_PRN();
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DLOG(INFO) << "Navigation Satellite set to " << d_satellite;
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}
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void beidou_b1i_telemetry_decoder_cc::set_channel(int channel)
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{
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d_channel = channel;
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d_BEIDOU_FSM.i_channel_ID = channel;
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DLOG(INFO) << "Navigation channel set to " << channel;
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// ############# ENABLE DATA FILE LOG #################
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if (d_dump == true)
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{
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if (d_dump_file.is_open() == false)
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{
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try
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{
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d_dump_filename = "telemetry";
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d_dump_filename.append(boost::lexical_cast<std::string>(d_channel));
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d_dump_filename.append(".dat");
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d_dump_file.exceptions(std::ifstream::failbit | std::ifstream::badbit);
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d_dump_file.open(d_dump_filename.c_str(), std::ios::out | std::ios::binary);
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LOG(INFO) << "Telemetry decoder dump enabled on channel " << d_channel
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<< " Log file: " << d_dump_filename.c_str();
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}
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catch (const std::ifstream::failure &e)
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{
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LOG(WARNING) << "channel " << d_channel << " Exception opening trk dump file " << e.what();
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}
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}
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}
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}
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void beidou_b1i_telemetry_decoder_cc::decodebch_bi1(int *bits, int *decbits)
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{
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int bit, err, reg[4] = {1, 1, 1, 1};
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int errind[15] = {14, 13, 10, 12, 6, 9, 4, 11, 0, 5, 7, 8, 1, 3, 2};
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for (unsigned int i = 0; i < 15; i++)
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{
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decbits[i] = bits[i];
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}
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for (unsigned int i = 0; i < 15; i++)
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{
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bit = reg[3];
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reg[3] = reg[2];
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reg[2] = reg[1];
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reg[1] = reg[0];
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reg[0] = bits[i] * bit;
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reg[1] *= bit;
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}
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err = errind[reg[0] + reg[1]*2 + reg[2]*4 + reg[3]*8];
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if (err > 0)
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{
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decbits[err - 1] *= -1;
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}
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}
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void beidou_b1i_telemetry_decoder_cc::decode_word(int word_counter, boost::circular_buffer<signed int> *d_bit_buffer, unsigned int& d_BEIDOU_frame_4bytes)
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{
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d_BEIDOU_frame_4bytes = 0;
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int bitsdec[30], bitsbch[30], first_branch[15], second_branch[15];
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if (word_counter == 1)
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{
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for (unsigned int j = 0; j < 30; j++)
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{
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bitsdec[j] = d_bit_buffer->at(j);
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}
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}
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else
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{
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for (unsigned int r = 0; r < 2; r++)
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{
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for (unsigned int c = 0; c < 15; c++)
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{
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bitsbch[r*15 + c] = d_bit_buffer->at(c*2 + r);
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}
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}
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decodebch_bi1(&bitsbch[0], first_branch);
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decodebch_bi1(&bitsbch[15], second_branch);
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for (unsigned int j = 0; j < 11; j++)
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{
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bitsdec[j] = first_branch[j];
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bitsdec[j + 11] = second_branch[j];
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}
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for (unsigned int j = 0; j < 4; j++)
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{
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bitsdec[j + 22] = first_branch[11 + j];
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bitsdec[j + 26] = second_branch[11 + j];
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}
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}
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for (unsigned int k = 0; k < 30 ; k++)
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{
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if (bitsdec[k] == 1)
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{
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d_BEIDOU_frame_4bytes++;
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}
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d_BEIDOU_frame_4bytes <<= 1;
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}
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d_BEIDOU_frame_4bytes >>= 1;
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}
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int beidou_b1i_telemetry_decoder_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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int corr_value = 0;
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int preamble_diff_ms = 0;
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int corr_NH = 0;
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Gnss_Synchro **out = reinterpret_cast<Gnss_Synchro **>(&output_items[0]); // Get the output buffer pointer
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const Gnss_Synchro **in = reinterpret_cast<const Gnss_Synchro **>(&input_items[0]); // Get the input buffer pointer
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new_sym = false;
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Gnss_Synchro current_symbol; //structure to save the synchronization information and send the output object to the next block
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//1. Copy the current tracking output
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current_symbol = in[0][0];
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double current_time_samples = current_symbol.Tracking_sample_counter;
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double current_samples_fs = current_symbol.fs;
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int symbol_value = 0;
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d_symbol_nh_history.push_back(current_symbol.Prompt_I); //add new symbol to the symbol queue
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consume_each(1);
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if (d_symbol_nh_history.size() == BEIDOU_B1I_NH_CODE_LENGTH)
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{
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for (int i = 0; i < BEIDOU_B1I_NH_CODE_LENGTH; i++)
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{
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if ((bits_NH[i] * d_symbol_nh_history.at(i)) > 0.0)
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{
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corr_NH += 1;
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}
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else
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{
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corr_NH -= 1;
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}
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}
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if (abs(corr_NH) == BEIDOU_B1I_NH_CODE_LENGTH)
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{
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sync_NH = true;
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if (corr_NH > 0)
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{
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symbol_value = 1;
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}
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else
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{
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symbol_value = -1;
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}
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//std::cout << symbol_value << std::endl;
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d_symbol_history.push_back(symbol_value);
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new_sym = true;
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d_symbol_nh_history.clear();
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}
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else
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{
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d_symbol_nh_history.pop_front();
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sync_NH = false;
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new_sym = false;
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}
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}
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if ((d_symbol_history.size() >= BEIDOU_B1I_PREAMBLE_LENGTH_BITS) and (d_make_correlation or !d_flag_frame_sync))
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{
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//******* preamble correlation ********
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for (unsigned int i = 0; i < BEIDOU_B1I_PREAMBLE_LENGTH_BITS; i++)
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{
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if (d_symbol_history.at(i) < 0) // symbols clipping
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{
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corr_value -= d_preambles_symbols[i];
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}
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else
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{
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corr_value += d_preambles_symbols[i];
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}
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}
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//std::cout << corr_value << std::endl;
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if (std::abs(corr_value) >= BEIDOU_B1I_PREAMBLE_LENGTH_BITS)
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{
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/* for (unsigned int i = 0; i < d_symbol_history.size() ; i++)
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{
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std::cout << d_symbol_history.at(i);
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}
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std::cout << std::endl;
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*/
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// std::cout << "SUCCESSFUL PREAMBLE CORRELATION" << std::endl;
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d_symbol_history.clear();
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d_symbol_counter_corr++;
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}
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}
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/*if (new_sym and )
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{
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flag_new_cnav_frame = beidou_nav_msg_decoder_add_symbol(&d_cnav_decoder, symbol_clip, &msg, &delay);
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new_sym = false;
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}*/
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d_flag_preamble = false;
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//******* frame sync ******************
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if (std::abs(corr_value) == BEIDOU_B1I_PREAMBLE_LENGTH_BITS)
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{
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// std::cout << "FRAME SYNC" << std::endl;
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//TODO: Rewrite with state machine
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if (d_stat == 0)
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{
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// std::cout << "STATE MACHINE" << std::endl;
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d_BEIDOU_FSM.Event_beidou_word_preamble();
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//record the preamble sample stamp
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d_preamble_time_samples = current_time_samples; // record the preamble sample stamp
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DLOG(INFO) << "Preamble detection for SAT " << this->d_satellite << "current_time_samples=" << current_time_samples;
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//sync the symbol to bits integrator
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d_symbol_accumulator = 0;
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d_symbol_accumulator_counter = 0;
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d_stat = 1; // enter into frame pre-detection status
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}
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else if (d_stat == 1) //check 6 seconds of preamble separation
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{
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// std::cout << "6 SECONDS" << std::endl;
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preamble_diff_ms = std::round(((static_cast<double>(current_time_samples) - d_preamble_time_samples) / static_cast<double>(current_samples_fs)) * 1000.0);
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if (std::abs(preamble_diff_ms - BEIDOU_SUBFRAME_MS) < 1)
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{
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std::cout << "Preamble confirmation for SAT" << std::endl;
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DLOG(INFO) << "Preamble confirmation for SAT " << this->d_satellite;
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d_BEIDOU_FSM.Event_beidou_word_preamble();
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d_flag_preamble = true;
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d_make_correlation = false;
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d_symbol_counter_corr = 0;
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d_preamble_time_samples = current_time_samples; // record the PRN start sample index associated to the preamble
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if (!d_flag_frame_sync)
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{
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d_flag_frame_sync = true;
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if (corr_value < 0)
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{
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flag_PLL_180_deg_phase_locked = true; // PLL is locked to opposite phase!
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DLOG(INFO) << " PLL in opposite phase for Sat " << this->d_satellite.get_PRN();
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}
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else
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{
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flag_PLL_180_deg_phase_locked = false;
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}
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DLOG(INFO) << " Frame sync SAT " << this->d_satellite << " with preamble start at "
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<< static_cast<double>(d_preamble_time_samples) / static_cast<double>(current_samples_fs) << " [s]";
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}
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}
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d_frame_bit_index = 10;
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d_symbol_history.clear();
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for (int i = 0; i < BEIDOU_B1I_PREAMBLE_LENGTH_BITS; i++)
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{
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d_bit_buffer.push_back(d_preambles_symbols[i]);
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}
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word_number = 0;
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}
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}
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else
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{
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d_symbol_counter_corr++;
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if (d_symbol_counter_corr > (BEIDOU_SUBFRAME_MS - BEIDOU_B1I_TELEMETRY_SYMBOLS_PER_BIT))
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{
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d_make_correlation = true;
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}
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if (d_stat == 1)
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{
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preamble_diff_ms = round(((static_cast<double>(current_time_samples) - static_cast<double>(d_preamble_time_samples)) / static_cast<double>(current_samples_fs)) * 1000.0);
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if (preamble_diff_ms > BEIDOU_SUBFRAME_MS + 1)
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{
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DLOG(INFO) << "Lost of frame sync SAT " << this->d_satellite << " preamble_diff= " << preamble_diff_ms;
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d_stat = 0; //lost of frame sync
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d_flag_frame_sync = false;
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flag_TOW_set = false;
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d_make_correlation = true;
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d_symbol_counter_corr = 0;
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}
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}
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}
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if (d_flag_frame_sync and new_sym)
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{
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// std::cout << symbol_value << std::endl;
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if (flag_PLL_180_deg_phase_locked)
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{
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d_bit_buffer.push_back(-symbol_value);
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}
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else
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{
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d_bit_buffer.push_back(symbol_value);
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}
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//******* bits to words ******
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d_frame_bit_index++;
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if (d_frame_bit_index == 30)
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{
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word_number++;
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beidou_b1i_telemetry_decoder_cc::decode_word(word_number, &d_bit_buffer, d_BEIDOU_frame_4bytes);
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// std::cout << d_BEIDOU_frame_4bytes << std::endl;
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d_bit_buffer.clear();
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d_frame_bit_index = 0;
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memcpy(&d_BEIDOU_FSM.d_BEIDOU_frame_4bytes, &d_BEIDOU_frame_4bytes, sizeof(char) * 4);
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//d_BEIDOU_FSM.d_preamble_time_ms = d_preamble_time_seconds * 1000.0;
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d_BEIDOU_FSM.Event_beidou_word_valid();
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// send TLM data to PVT using asynchronous message queues
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if (d_BEIDOU_FSM.d_flag_new_subframe == true)
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{
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/* switch (d_BEIDOU_FSM.d_subframe_ID)
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{
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case 3: //we have a new set of ephemeris data for the current SV
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*/ if (d_BEIDOU_FSM.d_nav.satellite_validation() == true)
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{
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// get ephemeris object for this SV (mandatory)
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std::shared_ptr<Beidou_Ephemeris> tmp_obj = std::make_shared<Beidou_Ephemeris>(d_BEIDOU_FSM.d_nav.get_ephemeris());
|
|
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
|
|
}
|
|
/* break;
|
|
case 4: // Possible IONOSPHERE and UTC model update (page 18)
|
|
*/ if (d_BEIDOU_FSM.d_nav.flag_iono_valid == true)
|
|
{
|
|
|
|
std::shared_ptr<Beidou_Iono> tmp_obj = std::make_shared<Beidou_Iono>(d_BEIDOU_FSM.d_nav.get_iono());
|
|
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
|
|
}
|
|
if (d_BEIDOU_FSM.d_nav.flag_utc_model_valid == true)
|
|
{
|
|
std::cout << " we have a new set of utc data for the current SV "<< std::endl;
|
|
|
|
std::shared_ptr<Beidou_Utc_Model> tmp_obj = std::make_shared<Beidou_Utc_Model>(d_BEIDOU_FSM.d_nav.get_utc_model());
|
|
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
|
|
}
|
|
/* break;
|
|
case 5:
|
|
// get almanac (if available)
|
|
//TODO: implement almanac reader in navigation_message
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
*/ d_BEIDOU_FSM.clear_flag_new_subframe();
|
|
d_flag_new_tow_available = true;
|
|
}
|
|
}
|
|
}
|
|
//2. Add the telemetry decoder information
|
|
if (this->d_flag_preamble == true and d_flag_new_tow_available == true)
|
|
{
|
|
d_TOW_at_current_symbol_ms = static_cast<unsigned int>(d_BEIDOU_FSM.d_nav.d_SOW) * 1000 + 599;
|
|
d_TOW_at_Preamble_ms = d_TOW_at_current_symbol_ms;
|
|
flag_TOW_set = true;
|
|
d_flag_new_tow_available = false;
|
|
}
|
|
else
|
|
{
|
|
d_TOW_at_current_symbol_ms += BEIDOU_B1I_CODE_PERIOD_MS;
|
|
}
|
|
|
|
current_symbol.TOW_at_current_symbol_ms = d_TOW_at_current_symbol_ms;
|
|
current_symbol.Flag_valid_word = flag_TOW_set;
|
|
|
|
if (flag_PLL_180_deg_phase_locked == true)
|
|
{
|
|
//correct the accumulated phase for the Costas loop phase shift, if required
|
|
current_symbol.Carrier_phase_rads += BEIDOU_PI;
|
|
}
|
|
|
|
if (d_dump == true)
|
|
{
|
|
// MULTIPLEXED FILE RECORDING - Record results to file
|
|
try
|
|
{
|
|
double tmp_double;
|
|
unsigned long int tmp_ulong_int;
|
|
tmp_double = static_cast<double>(d_TOW_at_current_symbol_ms) / 1000.0;
|
|
d_dump_file.write(reinterpret_cast<char *>(&tmp_double), sizeof(double));
|
|
tmp_ulong_int = current_symbol.Tracking_sample_counter;
|
|
d_dump_file.write(reinterpret_cast<char *>(&tmp_ulong_int), sizeof(unsigned long int));
|
|
tmp_double = static_cast<double>(d_TOW_at_Preamble_ms) * 1000.0;
|
|
d_dump_file.write(reinterpret_cast<char *>(&tmp_double), sizeof(double));
|
|
}
|
|
catch (const std::ifstream::failure &e)
|
|
{
|
|
LOG(WARNING) << "Exception writing observables dump file " << e.what();
|
|
}
|
|
}
|
|
|
|
//3. Make the output (copy the object contents to the GNURadio reserved memory)
|
|
*out[0] = current_symbol;
|
|
|
|
return 1;
|
|
}
|