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gnss-sdr/src/algorithms/telemetry_decoder/gnuradio_blocks/beidou_b1i_telemetry_decode...

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/*!
* \file beidou_b1i_telemetry_decoder_gs.cc
* \brief Implementation of a BEIDOU BI1 DNAV data decoder block
* \note Code added as part of GSoC 2018 program
* \author Damian Miralles, 2018. dmiralles2009(at)gmail.com
* \author Sergi Segura, 2018. sergi.segura.munoz(at)gmail.es
*
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2019 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
*
* This file is part of GNSS-SDR.
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
* -------------------------------------------------------------------------
*/
#include "beidou_b1i_telemetry_decoder_gs.h"
#include "Beidou_B1I.h"
#include "Beidou_DNAV.h"
#include "beidou_dnav_almanac.h"
#include "beidou_dnav_ephemeris.h"
#include "beidou_dnav_iono.h"
#include "beidou_dnav_utc_model.h"
#include "display.h"
#include "gnss_synchro.h"
#include <glog/logging.h>
#include <gnuradio/io_signature.h>
#include <pmt/pmt.h> // for make_any
#include <pmt/pmt_sugar.h> // for mp
#include <cstdlib> // for abs
#include <exception> // for exception
#include <iostream> // for cout
#include <memory> // for shared_ptr, make_shared
#define CRC_ERROR_LIMIT 8
beidou_b1i_telemetry_decoder_gs_sptr
beidou_b1i_make_telemetry_decoder_gs(const Gnss_Satellite &satellite, bool dump)
{
return beidou_b1i_telemetry_decoder_gs_sptr(new beidou_b1i_telemetry_decoder_gs(satellite, dump));
}
beidou_b1i_telemetry_decoder_gs::beidou_b1i_telemetry_decoder_gs(
const Gnss_Satellite &satellite,
bool dump) : gr::block("beidou_b1i_telemetry_decoder_gs",
gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)),
gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)))
{
// prevent telemetry symbols accumulation in output buffers
this->set_max_noutput_items(1);
// Ephemeris data port out
this->message_port_register_out(pmt::mp("telemetry"));
// Control messages to tracking block
this->message_port_register_out(pmt::mp("telemetry_to_trk"));
// initialize internal vars
d_dump = dump;
d_satellite = Gnss_Satellite(satellite.get_system(), satellite.get_PRN());
LOG(INFO) << "Initializing BeiDou B1I Telemetry Decoding for satellite " << this->d_satellite;
d_symbol_duration_ms = BEIDOU_B1I_TELEMETRY_SYMBOLS_PER_BIT * BEIDOU_B1I_CODE_PERIOD_MS;
d_symbols_per_preamble = BEIDOU_DNAV_PREAMBLE_LENGTH_SYMBOLS;
d_samples_per_preamble = BEIDOU_DNAV_PREAMBLE_LENGTH_SYMBOLS;
d_preamble_period_samples = BEIDOU_DNAV_PREAMBLE_PERIOD_SYMBOLS;
// Setting samples of preamble code
for (int32_t i = 0; i < d_symbols_per_preamble; i++)
{
if (BEIDOU_DNAV_PREAMBLE[i] == '1')
{
d_preamble_samples[i] = 1;
}
else
{
d_preamble_samples[i] = -1;
}
}
d_required_symbols = BEIDOU_DNAV_SUBFRAME_SYMBOLS + d_samples_per_preamble;
d_symbol_history.set_capacity(d_required_symbols);
d_last_valid_preamble = 0;
d_sent_tlm_failed_msg = false;
d_flag_valid_word = false;
// Generic settings
d_sample_counter = 0;
d_stat = 0;
d_preamble_index = 0;
d_flag_frame_sync = false;
d_TOW_at_current_symbol_ms = 0U;
d_TOW_at_Preamble_ms = 0U;
Flag_valid_word = false;
d_CRC_error_counter = 0;
d_flag_preamble = false;
d_channel = 0;
flag_SOW_set = false;
}
beidou_b1i_telemetry_decoder_gs::~beidou_b1i_telemetry_decoder_gs()
{
DLOG(INFO) << "BeiDou B1I Telemetry decoder block (channel " << d_channel << ") destructor called.";
if (d_dump_file.is_open() == true)
{
try
{
d_dump_file.close();
}
catch (const std::exception &ex)
{
LOG(WARNING) << "Exception in destructor closing the dump file " << ex.what();
}
}
}
void beidou_b1i_telemetry_decoder_gs::decode_bch15_11_01(const int32_t *bits, std::array<int32_t, 15> &decbits)
{
int32_t bit;
int32_t err;
std::array<int32_t, 4> reg{-1, -1, -1, -1};
const std::array<int32_t, 15> errind{14, 13, 10, 12, 6, 9, 4, 11, 0, 5, 7, 8, 1, 3, 2};
for (uint32_t i = 0; i < 15; i++)
{
decbits[i] = bits[i];
}
for (uint32_t i = 0; i < 15; i++)
{
bit = reg[3];
reg[3] = reg[2];
reg[2] = reg[1];
reg[1] = reg[0];
reg[0] = bits[i] * bit;
reg[1] *= bit;
}
for (uint32_t i = 0; i < 4; ++i)
{
reg[i] = (reg[i] + 1) / 2;
}
err = reg[0] + reg[1] * 2 + reg[2] * 4 + reg[3] * 8;
if (err > 0 and err < 16)
{
decbits[errind[err - 1]] *= -1;
}
}
void beidou_b1i_telemetry_decoder_gs::decode_word(
int32_t word_counter,
const float *enc_word_symbols,
int32_t *dec_word_symbols)
{
std::array<int32_t, 30> bitsbch{};
std::array<int32_t, 15> first_branch{};
std::array<int32_t, 15> second_branch{};
if (word_counter == 1)
{
for (uint32_t j = 0; j < 30; j++)
{
dec_word_symbols[j] = static_cast<int32_t>(enc_word_symbols[j] > 0) ? (1) : (-1);
}
}
else
{
for (uint32_t r = 0; r < 2; r++)
{
for (uint32_t c = 0; c < 15; c++)
{
bitsbch[r * 15 + c] = static_cast<int32_t>(enc_word_symbols[c * 2 + r] > 0) ? (1) : (-1);
}
}
decode_bch15_11_01(&bitsbch[0], first_branch);
decode_bch15_11_01(&bitsbch[15], second_branch);
for (uint32_t j = 0; j < 11; j++)
{
dec_word_symbols[j] = first_branch[j];
dec_word_symbols[j + 11] = second_branch[j];
}
for (uint32_t j = 0; j < 4; j++)
{
dec_word_symbols[j + 22] = first_branch[11 + j];
dec_word_symbols[j + 26] = second_branch[11 + j];
}
}
}
void beidou_b1i_telemetry_decoder_gs::decode_subframe(float *frame_symbols)
{
// 1. Transform from symbols to bits
std::string data_bits;
std::array<int32_t, 30> dec_word_bits{};
// Decode each word in subframe
for (uint32_t ii = 0; ii < BEIDOU_DNAV_WORDS_SUBFRAME; ii++)
{
// decode the word
decode_word((ii + 1), &frame_symbols[ii * 30], dec_word_bits.data());
// Save word to string format
for (uint32_t jj = 0; jj < (BEIDOU_DNAV_WORD_LENGTH_BITS); jj++)
{
data_bits.push_back((dec_word_bits[jj] > 0) ? ('1') : ('0'));
}
}
if (d_satellite.get_PRN() > 0 and d_satellite.get_PRN() < 6)
{
d_nav.d2_subframe_decoder(data_bits);
}
else
{
d_nav.d1_subframe_decoder(data_bits);
}
// 3. Check operation executed correctly
if (d_nav.get_flag_CRC_test() == true)
{
DLOG(INFO) << "BeiDou DNAV CRC correct in channel " << d_channel
<< " from satellite " << d_satellite;
}
else
{
DLOG(INFO) << "BeiDou DNAV CRC error in channel " << d_channel
<< " from satellite " << d_satellite;
}
// 4. Push the new navigation data to the queues
if (d_nav.have_new_ephemeris() == true)
{
// get object for this SV (mandatory)
std::shared_ptr<Beidou_Dnav_Ephemeris> tmp_obj = std::make_shared<Beidou_Dnav_Ephemeris>(d_nav.get_ephemeris());
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
LOG(INFO) << "BEIDOU DNAV Ephemeris have been received in channel" << d_channel << " from satellite " << d_satellite;
std::cout << TEXT_YELLOW << "New BEIDOU B1I DNAV message received in channel " << d_channel << ": ephemeris from satellite " << d_satellite << TEXT_RESET << std::endl;
}
if (d_nav.have_new_utc_model() == true)
{
// get object for this SV (mandatory)
std::shared_ptr<Beidou_Dnav_Utc_Model> tmp_obj = std::make_shared<Beidou_Dnav_Utc_Model>(d_nav.get_utc_model());
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
LOG(INFO) << "BEIDOU DNAV UTC Model have been received in channel" << d_channel << " from satellite " << d_satellite;
std::cout << TEXT_YELLOW << "New BEIDOU B1I DNAV utc model message received in channel " << d_channel << ": UTC model parameters from satellite " << d_satellite << TEXT_RESET << std::endl;
}
if (d_nav.have_new_iono() == true)
{
// get object for this SV (mandatory)
std::shared_ptr<Beidou_Dnav_Iono> tmp_obj = std::make_shared<Beidou_Dnav_Iono>(d_nav.get_iono());
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
LOG(INFO) << "BEIDOU DNAV Iono have been received in channel" << d_channel << " from satellite " << d_satellite;
std::cout << TEXT_YELLOW << "New BEIDOU B1I DNAV Iono message received in channel " << d_channel << ": Iono model parameters from satellite " << d_satellite << TEXT_RESET << std::endl;
}
if (d_nav.have_new_almanac() == true)
{
// uint32_t slot_nbr = d_nav.i_alm_satellite_PRN;
// std::shared_ptr<Beidou_Dnav_Almanac> tmp_obj = std::make_shared<Beidou_Dnav_Almanac>(d_nav.get_almanac(slot_nbr));
// this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
LOG(INFO) << "BEIDOU DNAV Almanac have been received in channel" << d_channel << " from satellite " << d_satellite << std::endl;
std::cout << TEXT_YELLOW << "New BEIDOU B1I DNAV almanac received in channel " << d_channel << " from satellite " << d_satellite << TEXT_RESET << std::endl;
}
}
void beidou_b1i_telemetry_decoder_gs::set_satellite(const Gnss_Satellite &satellite)
{
uint32_t sat_prn = 0;
d_satellite = Gnss_Satellite(satellite.get_system(), satellite.get_PRN());
DLOG(INFO) << "Setting decoder Finite State Machine to satellite " << d_satellite;
DLOG(INFO) << "Navigation Satellite set to " << d_satellite;
// Update satellite information for DNAV decoder
sat_prn = d_satellite.get_PRN();
d_nav.set_satellite_PRN(sat_prn);
d_nav.set_signal_type(1); // BDS: data source (0:unknown,1:B1I,2:B1Q,3:B2I,4:B2Q,5:B3I,6:B3Q)
// Update tel dec parameters for D2 NAV Messages
if (sat_prn > 0 and sat_prn < 6)
{
d_symbols_per_preamble = BEIDOU_DNAV_PREAMBLE_LENGTH_SYMBOLS;
d_samples_per_preamble = BEIDOU_DNAV_PREAMBLE_LENGTH_SYMBOLS;
d_preamble_period_samples = BEIDOU_DNAV_PREAMBLE_PERIOD_SYMBOLS;
// Setting samples of preamble code
for (int32_t i = 0; i < d_symbols_per_preamble; i++)
{
if (BEIDOU_DNAV_PREAMBLE[i] == '1')
{
d_preamble_samples[i] = 1;
}
else
{
d_preamble_samples[i] = -1;
}
}
d_symbol_duration_ms = BEIDOU_B1I_GEO_TELEMETRY_SYMBOLS_PER_BIT * BEIDOU_B1I_CODE_PERIOD_MS;
d_required_symbols = BEIDOU_DNAV_SUBFRAME_SYMBOLS + d_samples_per_preamble;
d_symbol_history.set_capacity(d_required_symbols);
}
else
{
// back to normal satellites
d_symbol_duration_ms = BEIDOU_B1I_TELEMETRY_SYMBOLS_PER_BIT * BEIDOU_B1I_CODE_PERIOD_MS;
d_symbols_per_preamble = BEIDOU_DNAV_PREAMBLE_LENGTH_SYMBOLS;
d_samples_per_preamble = BEIDOU_DNAV_PREAMBLE_LENGTH_SYMBOLS;
d_preamble_period_samples = BEIDOU_DNAV_PREAMBLE_PERIOD_SYMBOLS;
// Setting samples of preamble code
for (int32_t i = 0; i < d_symbols_per_preamble; i++)
{
if (BEIDOU_DNAV_PREAMBLE[i] == '1')
{
d_preamble_samples[i] = 1;
}
else
{
d_preamble_samples[i] = -1;
}
}
d_required_symbols = BEIDOU_DNAV_SUBFRAME_SYMBOLS + d_samples_per_preamble;
d_symbol_history.set_capacity(d_required_symbols);
}
}
void beidou_b1i_telemetry_decoder_gs::set_channel(int32_t channel)
{
d_channel = channel;
LOG(INFO) << "Navigation channel set to " << channel;
// ############# ENABLE DATA FILE LOG #################
if (d_dump == true)
{
if (d_dump_file.is_open() == false)
{
try
{
d_dump_filename = "telemetry";
d_dump_filename.append(std::to_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) << "Telemetry decoder 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 Beidou TLM dump file. " << e.what();
}
}
}
}
void beidou_b1i_telemetry_decoder_gs::reset()
{
d_last_valid_preamble = d_sample_counter;
d_TOW_at_current_symbol_ms = 0;
d_sent_tlm_failed_msg = false;
d_flag_valid_word = false;
DLOG(INFO) << "Beidou B1I Telemetry decoder reset for satellite " << d_satellite;
}
int beidou_b1i_telemetry_decoder_gs::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)
{
int32_t corr_value = 0;
int32_t preamble_diff = 0;
auto **out = reinterpret_cast<Gnss_Synchro **>(&output_items[0]); // Get the output buffer pointer
const auto **in = reinterpret_cast<const Gnss_Synchro **>(&input_items[0]); // Get the input buffer pointer
Gnss_Synchro current_symbol{}; // structure to save the synchronization information and send the output object to the next block
// 1. Copy the current tracking output
current_symbol = in[0][0];
d_symbol_history.push_back(current_symbol.Prompt_I); // add new symbol to the symbol queue
d_sample_counter++; // count for the processed samples
consume_each(1);
d_flag_preamble = false;
if (d_symbol_history.size() >= d_required_symbols)
{
// ******* preamble correlation ********
for (int32_t i = 0; i < d_samples_per_preamble; i++)
{
if (d_symbol_history[i] < 0) // symbols clipping
{
corr_value -= d_preamble_samples[i];
}
else
{
corr_value += d_preamble_samples[i];
}
}
}
// ******* frame sync ******************
if (d_stat == 0) // no preamble information
{
if (abs(corr_value) >= d_samples_per_preamble)
{
// Record the preamble sample stamp
d_preamble_index = d_sample_counter;
DLOG(INFO) << "Preamble detection for BEIDOU B1I SAT " << this->d_satellite;
// Enter into frame pre-detection status
d_stat = 1;
}
}
else if (d_stat == 1) // possible preamble lock
{
if (abs(corr_value) >= d_samples_per_preamble)
{
// check preamble separation
preamble_diff = static_cast<int32_t>(d_sample_counter - d_preamble_index);
if (abs(preamble_diff - d_preamble_period_samples) == 0)
{
// try to decode frame
DLOG(INFO) << "Starting BeiDou DNAV frame decoding for BeiDou B1I SAT " << this->d_satellite;
d_preamble_index = d_sample_counter; // record the preamble sample stamp
d_stat = 2;
// ******* SAMPLES TO SYMBOLS *******
if (corr_value > 0) // normal PLL lock
{
for (uint32_t i = 0; i < BEIDOU_DNAV_PREAMBLE_PERIOD_SYMBOLS; i++)
{
d_subframe_symbols[i] = d_symbol_history[i];
}
}
else // 180 deg. inverted carrier phase PLL lock
{
for (uint32_t i = 0; i < BEIDOU_DNAV_PREAMBLE_PERIOD_SYMBOLS; i++)
{
d_subframe_symbols[i] = -d_symbol_history[i];
}
}
// call the decoder
decode_subframe(d_subframe_symbols.data());
if (d_nav.get_flag_CRC_test() == true)
{
d_CRC_error_counter = 0;
d_flag_preamble = true; // valid preamble indicator (initialized to false every work())
d_preamble_index = d_sample_counter; // record the preamble sample stamp (t_P)
if (!d_flag_frame_sync)
{
d_flag_frame_sync = true;
DLOG(INFO) << "BeiDou DNAV frame sync found for SAT " << this->d_satellite;
}
}
else
{
d_CRC_error_counter++;
d_preamble_index = d_sample_counter; // record the preamble sample stamp
if (d_CRC_error_counter > CRC_ERROR_LIMIT)
{
DLOG(INFO) << "BeiDou DNAV frame sync lost for SAT " << this->d_satellite;
d_flag_frame_sync = false;
d_stat = 0;
flag_SOW_set = false;
}
}
}
else
{
if (preamble_diff > d_preamble_period_samples)
{
d_stat = 0; // start again
}
DLOG(INFO) << "Failed BeiDou DNAV frame decoding for BeiDou B1I SAT " << this->d_satellite;
}
}
}
else if (d_stat == 2) // preamble acquired
{
if (d_sample_counter == d_preamble_index + static_cast<uint64_t>(d_preamble_period_samples))
{
// ******* SAMPLES TO SYMBOLS *******
if (corr_value > 0) // normal PLL lock
{
for (uint32_t i = 0; i < BEIDOU_DNAV_PREAMBLE_PERIOD_SYMBOLS; i++)
{
d_subframe_symbols[i] = d_symbol_history[i];
}
}
else // 180 deg. inverted carrier phase PLL lock
{
for (uint32_t i = 0; i < BEIDOU_DNAV_PREAMBLE_PERIOD_SYMBOLS; i++)
{
d_subframe_symbols[i] = -d_symbol_history[i];
}
}
// call the decoder
decode_subframe(d_subframe_symbols.data());
if (d_nav.get_flag_CRC_test() == true)
{
d_CRC_error_counter = 0;
d_flag_preamble = true; // valid preamble indicator (initialized to false every work())
d_preamble_index = d_sample_counter; // record the preamble sample stamp (t_P)
if (!d_flag_frame_sync)
{
d_flag_frame_sync = true;
DLOG(INFO) << "BeiDou DNAV frame sync found for SAT " << this->d_satellite;
}
}
else
{
d_CRC_error_counter++;
d_preamble_index = d_sample_counter; // record the preamble sample stamp
if (d_CRC_error_counter > CRC_ERROR_LIMIT)
{
DLOG(INFO) << "BeiDou DNAV frame sync lost for SAT " << this->d_satellite;
d_flag_frame_sync = false;
d_stat = 0;
flag_SOW_set = false;
}
}
}
}
// UPDATE GNSS SYNCHRO DATA
// 2. Add the telemetry decoder information
if (this->d_flag_preamble == true and d_nav.get_flag_new_SOW_available() == true)
// update TOW at the preamble instant
{
// Reporting sow as gps time of week
d_TOW_at_Preamble_ms = static_cast<uint32_t>((d_nav.get_SOW() + BEIDOU_DNAV_BDT2GPST_LEAP_SEC_OFFSET) * 1000.0);
// check TOW update consistency
uint32_t last_d_TOW_at_current_symbol_ms = d_TOW_at_current_symbol_ms;
// compute new TOW
d_TOW_at_current_symbol_ms = d_TOW_at_Preamble_ms + d_required_symbols * d_symbol_duration_ms;
flag_SOW_set = true;
d_nav.set_flag_new_SOW_available(false);
if (last_d_TOW_at_current_symbol_ms != 0 and abs(static_cast<int64_t>(d_TOW_at_current_symbol_ms) - int64_t(last_d_TOW_at_current_symbol_ms)) > static_cast<int64_t>(d_symbol_duration_ms))
{
LOG(INFO) << "Warning: BEIDOU B1I TOW update in ch " << d_channel
<< " does not match the TLM TOW counter " << static_cast<int64_t>(d_TOW_at_current_symbol_ms) - int64_t(last_d_TOW_at_current_symbol_ms) << " ms \n";
d_TOW_at_current_symbol_ms = 0;
d_flag_valid_word = false;
}
else
{
d_last_valid_preamble = d_sample_counter;
d_flag_valid_word = true;
}
}
else
{
if (d_flag_valid_word)
{
d_TOW_at_current_symbol_ms += d_symbol_duration_ms;
if (current_symbol.Flag_valid_symbol_output == false)
{
d_flag_valid_word = false;
}
}
}
if (d_flag_valid_word == true)
{
current_symbol.TOW_at_current_symbol_ms = d_TOW_at_current_symbol_ms;
current_symbol.Flag_valid_word = d_flag_valid_word;
if (d_dump == true)
{
// MULTIPLEXED FILE RECORDING - Record results to file
try
{
double tmp_double;
uint64_t 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(uint64_t));
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 Telemetry GPS L5 dump file " << e.what();
}
}
// 3. Make the output (copy the object contents to the GNURadio reserved memory)
*out[0] = current_symbol;
return 1;
}
return 0;
}
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