gnss-sdr/src/algorithms/telemetry_decoder/gnuradio_blocks/gps_l5_telemetry_decoder_cc.cc

287 lines
12 KiB
C++

/*!
* \file gps_l5_telemetry_decoder_cc.cc
* \brief Implementation of a CNAV message demodulator block
* \author Antonio Ramos, 2017. antonio.ramos(at)cttc.es
*
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2018 (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 <https://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#include "gps_l5_telemetry_decoder_cc.h"
#include "display.h"
#include "gnss_synchro.h"
#include "gps_cnav_ephemeris.h"
#include "gps_cnav_iono.h"
#include <boost/lexical_cast.hpp>
#include <glog/logging.h>
#include <gnuradio/io_signature.h>
#include <bitset>
#include <iostream>
#include <sstream>
using google::LogMessage;
gps_l5_telemetry_decoder_cc_sptr
gps_l5_make_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump)
{
return gps_l5_telemetry_decoder_cc_sptr(new gps_l5_telemetry_decoder_cc(satellite, dump));
}
gps_l5_telemetry_decoder_cc::gps_l5_telemetry_decoder_cc(
const Gnss_Satellite &satellite, bool dump) : gr::block("gps_l5_telemetry_decoder_cc",
gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)),
gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)))
{
// Ephemeris data port out
this->message_port_register_out(pmt::mp("telemetry"));
// initialize internal vars
d_dump = dump;
d_satellite = Gnss_Satellite(satellite.get_system(), satellite.get_PRN());
DLOG(INFO) << "GPS L5 TELEMETRY PROCESSING: satellite " << d_satellite;
d_channel = 0;
d_flag_valid_word = false;
d_TOW_at_current_symbol_ms = 0U;
d_TOW_at_Preamble_ms = 0U;
// initialize the CNAV frame decoder (libswiftcnav)
cnav_msg_decoder_init(&d_cnav_decoder);
for (int32_t aux = 0; aux < GPS_L5I_NH_CODE_LENGTH; aux++)
{
if (GPS_L5I_NH_CODE[aux] == 0)
{
bits_NH[aux] = -1.0;
}
else
{
bits_NH[aux] = 1.0;
}
}
sync_NH = false;
new_sym = false;
}
gps_l5_telemetry_decoder_cc::~gps_l5_telemetry_decoder_cc()
{
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 gps_l5_telemetry_decoder_cc::set_satellite(const Gnss_Satellite &satellite)
{
d_satellite = Gnss_Satellite(satellite.get_system(), satellite.get_PRN());
LOG(INFO) << "GPS L5 CNAV telemetry decoder in channel " << this->d_channel << " set to satellite " << d_satellite;
d_CNAV_Message.reset();
}
void gps_l5_telemetry_decoder_cc::set_channel(int32_t channel)
{
d_channel = channel;
d_CNAV_Message.reset();
LOG(INFO) << "GPS L5 CNAV channel set to " << channel;
// ############# ENABLE DATA FILE LOG #################
if (d_dump == true)
{
if (d_dump_file.is_open() == false)
{
try
{
d_dump_filename = "telemetry_L5_";
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 Telemetry GPS L5 dump file " << e.what();
}
}
}
}
int gps_l5_telemetry_decoder_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)
{
// get pointers on in- and output gnss-synchro objects
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
// UPDATE GNSS SYNCHRO DATA
Gnss_Synchro current_synchro_data{}; //structure to save the synchronization information and send the output object to the next block
// 1. Copy the current tracking output
current_synchro_data = in[0];
consume_each(1); //one by one
sym_hist.push_back(in[0].Prompt_I);
int32_t corr_NH = 0;
int32_t symbol_value = 0;
// Search correlation with Neuman-Hofman Code (see IS-GPS-705D)
if (sym_hist.size() == GPS_L5I_NH_CODE_LENGTH)
{
for (int32_t i = 0; i < GPS_L5I_NH_CODE_LENGTH; i++)
{
if ((bits_NH[i] * sym_hist.at(i)) > 0.0)
{
corr_NH += 1;
}
else
{
corr_NH -= 1;
}
}
if (abs(corr_NH) == GPS_L5I_NH_CODE_LENGTH)
{
sync_NH = true;
if (corr_NH > 0)
{
symbol_value = 1;
}
else
{
symbol_value = -1;
}
new_sym = true;
sym_hist.clear();
}
else
{
sym_hist.pop_front();
sync_NH = false;
new_sym = false;
}
}
bool flag_new_cnav_frame = false;
cnav_msg_t msg;
uint32_t delay = 0;
// add the symbol to the decoder
if (new_sym)
{
uint8_t symbol_clip = static_cast<uint8_t>(symbol_value > 0) * 255;
flag_new_cnav_frame = cnav_msg_decoder_add_symbol(&d_cnav_decoder, symbol_clip, &msg, &delay);
new_sym = false;
}
// 2. Add the telemetry decoder information
// check if new CNAV frame is available
if (flag_new_cnav_frame == true)
{
std::bitset<GPS_L5_CNAV_DATA_PAGE_BITS> raw_bits;
// Expand packet bits to bitsets. Notice the reverse order of the bits sequence, required by the CNAV message decoder
for (uint32_t i = 0; i < GPS_L5_CNAV_DATA_PAGE_BITS; i++)
{
raw_bits[GPS_L5_CNAV_DATA_PAGE_BITS - 1 - i] = ((msg.raw_msg[i / 8] >> (7 - i % 8)) & 1u);
}
d_CNAV_Message.decode_page(raw_bits);
// Push the new navigation data to the queues
if (d_CNAV_Message.have_new_ephemeris() == true)
{
// get ephemeris object for this SV
std::shared_ptr<Gps_CNAV_Ephemeris> tmp_obj = std::make_shared<Gps_CNAV_Ephemeris>(d_CNAV_Message.get_ephemeris());
std::cout << TEXT_MAGENTA << "New GPS L5 CNAV message received in channel " << d_channel << ": ephemeris from satellite " << d_satellite << TEXT_RESET << std::endl;
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
}
if (d_CNAV_Message.have_new_iono() == true)
{
std::shared_ptr<Gps_CNAV_Iono> tmp_obj = std::make_shared<Gps_CNAV_Iono>(d_CNAV_Message.get_iono());
std::cout << TEXT_MAGENTA << "New GPS L5 CNAV message received in channel " << d_channel << ": iono model parameters from satellite " << d_satellite << TEXT_RESET << std::endl;
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
}
if (d_CNAV_Message.have_new_utc_model() == true)
{
std::shared_ptr<Gps_CNAV_Utc_Model> tmp_obj = std::make_shared<Gps_CNAV_Utc_Model>(d_CNAV_Message.get_utc_model());
std::cout << TEXT_MAGENTA << "New GPS L5 CNAV message received in channel " << d_channel << ": UTC model parameters from satellite " << d_satellite << TEXT_RESET << std::endl;
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
}
// update TOW at the preamble instant
d_TOW_at_Preamble_ms = msg.tow * 6000;
// The time of the last input symbol can be computed from the message ToW and
// delay by the formulae:
// \code
// symbolTime_ms = msg->tow * 6000 + *pdelay * 10 + (12 * 10); 12 symbols of the encoder's transitory
d_TOW_at_current_symbol_ms = msg.tow * 6000 + (delay + 12) * GPS_L5I_SYMBOL_PERIOD_MS;
d_flag_valid_word = true;
}
else
{
d_TOW_at_current_symbol_ms += GPS_L5I_PERIOD_MS;
if (current_synchro_data.Flag_valid_symbol_output == false)
{
d_flag_valid_word = false;
}
}
if (d_flag_valid_word == true)
{
current_synchro_data.TOW_at_current_symbol_ms = d_TOW_at_current_symbol_ms;
current_synchro_data.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_synchro_data.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_synchro_data;
return 1;
}
return 0;
}