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/*!
* \file galileo_e1b_telemetry_decoder_cc.cc
* \brief Implementation of a Galileo INAV message demodulator block
* \author Mara Branzanti 2013. mara.branzanti(at)gmail.com
* \author Javier Arribas 2013. jarribas(at)cttc.es
*
* -------------------------------------------------------------------------
*
* 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_e1b_telemetry_decoder_cc.h"
#include <iostream>
#include <boost/lexical_cast.hpp>
#include <gnuradio/io_signature.h>
#include <glog/logging.h>
#include "control_message_factory.h"
#include "gnss_synchro.h"
#include "convolutional.h"
#define CRC_ERROR_LIMIT 6
using google::LogMessage;
galileo_e1b_telemetry_decoder_cc_sptr
galileo_e1b_make_telemetry_decoder_cc(const Gnss_Satellite & satellite, bool dump)
{
return galileo_e1b_telemetry_decoder_cc_sptr(new galileo_e1b_telemetry_decoder_cc(satellite, dump));
}
void galileo_e1b_telemetry_decoder_cc::viterbi_decoder(double *page_part_symbols, int *page_part_bits)
{
int CodeLength = 240;
int DataLength;
int nn, KK, mm, max_states;
int g_encoder[2];
nn = 2; // Coding rate 1/n
KK = 7; // Constraint Length
g_encoder[0] = 121; // Polynomial G1
g_encoder[1] = 91; // Polynomial G2
mm = KK - 1;
max_states = 1 << mm; /* 2^mm */
DataLength = (CodeLength/nn) - mm;
/* create appropriate transition matrices */
int *out0, *out1, *state0, *state1;
out0 = static_cast<int*>(calloc( max_states, sizeof(int) ));
out1 = static_cast<int*>(calloc( max_states, sizeof(int) ));
state0 = static_cast<int*>(calloc( max_states, sizeof(int) ));
state1 = static_cast<int*>(calloc( max_states, sizeof(int) ));
nsc_transit( out0, state0, 0, g_encoder, KK, nn );
nsc_transit( out1, state1, 1, g_encoder, KK, nn );
Viterbi(page_part_bits, out0, state0, out1, state1,
page_part_symbols, KK, nn, DataLength );
/* Clean up memory */
free( out0 );
free( out1 );
free( state0 );
free( state1 );
}
void galileo_e1b_telemetry_decoder_cc::deinterleaver(int rows, int cols, double *in, double *out)
{
for (int r = 0; r < rows; r++)
{
for(int c = 0; c < cols; c++)
{
out[c*rows + r] = in[r*cols + c];
}
}
}
galileo_e1b_telemetry_decoder_cc::galileo_e1b_telemetry_decoder_cc(
const Gnss_Satellite & satellite,
bool dump) :
gr::block("galileo_e1b_telemetry_decoder_cc", gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)),
gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)))
{
// Telemetry Bit transition synchronization port out
this->message_port_register_out(pmt::mp("preamble_timestamp_s"));
// 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());
LOG(INFO) << "Initializing GALILEO E1B TELEMETRY PROCESSING";
d_samples_per_symbol = ( Galileo_E1_CODE_CHIP_RATE_HZ / Galileo_E1_B_CODE_LENGTH_CHIPS ) / Galileo_E1_B_SYMBOL_RATE_BPS;
// set the preamble
unsigned short int preambles_bits[GALILEO_INAV_PREAMBLE_LENGTH_BITS] = GALILEO_INAV_PREAMBLE;
d_symbols_per_preamble = GALILEO_INAV_PREAMBLE_LENGTH_BITS * d_samples_per_symbol;
memcpy(static_cast<unsigned short int*>(this->d_preambles_bits), static_cast<unsigned short int*>(preambles_bits), GALILEO_INAV_PREAMBLE_LENGTH_BITS * sizeof(unsigned short int));
// preamble bits to sampled symbols
d_preambles_symbols = static_cast<signed int*>(malloc(sizeof(signed int) * d_symbols_per_preamble));
int n = 0;
for (int i = 0; i < GALILEO_INAV_PREAMBLE_LENGTH_BITS; i++)
{
for (unsigned int j = 0; j < d_samples_per_symbol; j++)
{
if (d_preambles_bits[i] == 1)
{
d_preambles_symbols[n] = 1;
}
else
{
d_preambles_symbols[n] = -1;
}
n++;
}
}
d_sample_counter = 0;
d_stat = 0;
d_preamble_index = 0;
d_flag_frame_sync = false;
d_flag_parity = false;
d_TOW_at_current_symbol = 0;
delta_t = 0;
d_CRC_error_counter = 0;
flag_even_word_arrived = 0;
d_flag_preamble = false;
d_channel = 0;
flag_TOW_set = false;
}
galileo_e1b_telemetry_decoder_cc::~galileo_e1b_telemetry_decoder_cc()
{
delete d_preambles_symbols;
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 galileo_e1b_telemetry_decoder_cc::decode_word(double *page_part_symbols,int frame_length)
{
double page_part_symbols_deint[frame_length];
// 1. De-interleave
deinterleaver(GALILEO_INAV_INTERLEAVER_ROWS, GALILEO_INAV_INTERLEAVER_COLS, page_part_symbols, page_part_symbols_deint);
// 2. Viterbi decoder
// 2.1 Take into account the NOT gate in G2 polynomial (Galileo ICD Figure 13, FEC encoder)
// 2.2 Take into account the possible inversion of the polarity due to PLL lock at 180<38>
for (int i = 0; i < frame_length; i++)
{
if ((i + 1) % 2 == 0)
{
page_part_symbols_deint[i] = -page_part_symbols_deint[i];
}
}
int page_part_bits[frame_length/2];
viterbi_decoder(page_part_symbols_deint, page_part_bits);
// 3. Call the Galileo page decoder
std::string page_String;
for(int i = 0; i < (frame_length/2); i++)
{
if (page_part_bits[i] > 0)
{
page_String.push_back('1');
}
else
{
page_String.push_back('0');
}
}
if (page_part_bits[0] == 1)
{
// DECODE COMPLETE WORD (even + odd) and TEST CRC
d_nav.split_page(page_String, flag_even_word_arrived);
if(d_nav.flag_CRC_test == true)
{
LOG(INFO) << "Galileo E1 CRC correct on channel " << d_channel << " from satellite " << d_satellite;
//std::cout << "Galileo E1 CRC correct on channel " << d_channel << " from satellite " << d_satellite << std::endl;
}
else
{
std::cout << "Galileo E1 CRC error on channel " << d_channel << " from satellite " << d_satellite << std::endl;
LOG(INFO) << "Galileo E1 CRC error on channel " << d_channel << " from satellite " << d_satellite;
}
flag_even_word_arrived = 0;
}
else
{
// STORE HALF WORD (even page)
d_nav.split_page(page_String.c_str(), flag_even_word_arrived);
flag_even_word_arrived = 1;
}
// 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<Galileo_Ephemeris> tmp_obj = std::make_shared<Galileo_Ephemeris>(d_nav.get_ephemeris());
std::cout << "New Galileo E1 I/NAV message received: ephemeris from satellite " << d_satellite << std::endl;
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
}
if (d_nav.have_new_iono_and_GST() == true)
{
// get object for this SV (mandatory)
std::shared_ptr<Galileo_Iono> tmp_obj = std::make_shared<Galileo_Iono>(d_nav.get_iono());
std::cout << "New Galileo E1 I/NAV message received: iono/GST model parameters from satellite " << d_satellite << std::endl;
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
}
if (d_nav.have_new_utc_model() == true)
{
// get object for this SV (mandatory)
std::shared_ptr<Galileo_Utc_Model> tmp_obj = std::make_shared<Galileo_Utc_Model>(d_nav.get_utc_model());
std::cout << "New Galileo E1 I/NAV message received: UTC model parameters from satellite " << d_satellite << std::endl;
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
}
if (d_nav.have_new_almanac() == true)
{
std::shared_ptr<Galileo_Almanac> tmp_obj= std::make_shared<Galileo_Almanac>(d_nav.get_almanac());
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
//debug
std::cout << "Galileo E1 I/NAV almanac received!" << std::endl;
DLOG(INFO) << "GPS_to_Galileo time conversion:";
DLOG(INFO) << "A0G=" << tmp_obj->A_0G_10;
DLOG(INFO) << "A1G=" << tmp_obj->A_1G_10;
DLOG(INFO) << "T0G=" << tmp_obj->t_0G_10;
DLOG(INFO) << "WN_0G_10=" << tmp_obj->WN_0G_10;
DLOG(INFO) << "Current parameters:";
DLOG(INFO) << "d_TOW_at_current_symbol=" << d_TOW_at_current_symbol;
DLOG(INFO) << "d_nav.WN_0=" << d_nav.WN_0;
delta_t = tmp_obj->A_0G_10 + tmp_obj->A_1G_10 * (d_TOW_at_current_symbol - tmp_obj->t_0G_10 + 604800 * (fmod((d_nav.WN_0 - tmp_obj->WN_0G_10), 64)));
DLOG(INFO) << "delta_t=" << delta_t << "[s]";
}
}
int galileo_e1b_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)
{
int corr_value = 0;
int preamble_diff = 0;
Gnss_Synchro **out = reinterpret_cast<Gnss_Synchro **>(&output_items[0]); // Get the output buffer pointer
const Gnss_Synchro **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); //add new symbol to the symbol queue
d_sample_counter++; //count for the processed samples
consume_each(1);
d_flag_preamble = false;
unsigned int required_symbols = GALILEO_INAV_PAGE_SYMBOLS + d_symbols_per_preamble;
if (d_symbol_history.size() > required_symbols)
{
// TODO Optimize me!
//******* preamble correlation ********
for (int i = 0; i < d_symbols_per_preamble; i++)
{
if (d_symbol_history.at(i).Prompt_I < 0) // symbols clipping
{
corr_value -= d_preambles_symbols[i];
}
else
{
corr_value += d_preambles_symbols[i];
}
}
}
//******* frame sync ******************
if (d_stat == 0) //no preamble information
{
if (abs(corr_value) >= d_symbols_per_preamble)
{
d_preamble_index = d_sample_counter;//record the preamble sample stamp
LOG(INFO) << "Preamble detection for Galileo satellite " << this->d_satellite;
d_stat = 1; // enter into frame pre-detection status
}
}
else if (d_stat == 1) // posible preamble lock
{
if (abs(corr_value) >= d_symbols_per_preamble)
{
//check preamble separation
preamble_diff = d_sample_counter - d_preamble_index;
if (abs(preamble_diff - GALILEO_INAV_PREAMBLE_PERIOD_SYMBOLS) == 0)
{
//try to decode frame
LOG(INFO) << "Starting page decoder for Galileo satellite " << this->d_satellite;
d_preamble_index = d_sample_counter; //record the preamble sample stamp
d_stat = 2;
}
else
{
if (preamble_diff > GALILEO_INAV_PREAMBLE_PERIOD_SYMBOLS)
{
d_stat = 0; // start again
}
}
}
}
else if (d_stat == 2)
{
if (d_sample_counter == d_preamble_index + GALILEO_INAV_PREAMBLE_PERIOD_SYMBOLS)
{
// NEW Galileo page part is received
// 0. fetch the symbols into an array
int frame_length = GALILEO_INAV_PAGE_PART_SYMBOLS - d_symbols_per_preamble;
double page_part_symbols[frame_length];
for (int i = 0; i < frame_length; i++)
{
if (corr_value > 0)
{
page_part_symbols[i] = d_symbol_history.at(i + d_symbols_per_preamble).Prompt_I; // because last symbol of the preamble is just received now!
}
else
{
page_part_symbols[i] = -d_symbol_history.at(i + d_symbols_per_preamble).Prompt_I; // because last symbol of the preamble is just received now!
}
}
//call the decoder
decode_word(page_part_symbols, frame_length);
if (d_nav.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) << " Frame sync SAT " << this->d_satellite << " with preamble start at "
<< d_symbol_history.at(0).Tracking_sample_counter << " [samples]";
}
}
else
{
d_CRC_error_counter++;
d_preamble_index = d_sample_counter; //record the preamble sample stamp
if (d_CRC_error_counter > CRC_ERROR_LIMIT)
{
LOG(INFO) << "Lost of frame sync SAT " << this->d_satellite;
d_flag_frame_sync = false;
d_stat = 0;
}
}
}
}
// UPDATE GNSS SYNCHRO DATA
//2. Add the telemetry decoder information
if (this->d_flag_preamble == true and d_nav.flag_TOW_set == true)
//update TOW at the preamble instant
{
if(d_nav.flag_TOW_5 == true) //page 5 arrived and decoded, so we are in the odd page (since Tow refers to the even page, we have to add 1 sec)
{
//TOW_5 refers to the even preamble, but when we decode it we are in the odd part, so 1 second later plus the decoding delay
d_TOW_at_current_symbol = d_nav.TOW_5 + GALILEO_INAV_PAGE_PART_SECONDS + (static_cast<double>(required_symbols)) * GALILEO_E1_CODE_PERIOD; //-GALILEO_E1_CODE_PERIOD;//+ (double)GALILEO_INAV_PREAMBLE_LENGTH_BITS/(double)GALILEO_TELEMETRY_RATE_BITS_SECOND;
d_nav.flag_TOW_5 = false;
}
else if(d_nav.flag_TOW_6 == true) //page 6 arrived and decoded, so we are in the odd page (since Tow refers to the even page, we have to add 1 sec)
{
//TOW_6 refers to the even preamble, but when we decode it we are in the odd part, so 1 second later plus the decoding delay
d_TOW_at_current_symbol = d_nav.TOW_6 + GALILEO_INAV_PAGE_PART_SECONDS + (static_cast<double>(required_symbols)) * GALILEO_E1_CODE_PERIOD;//-GALILEO_E1_CODE_PERIOD;//+ (double)GALILEO_INAV_PREAMBLE_LENGTH_BITS/(double)GALILEO_TELEMETRY_RATE_BITS_SECOND;
d_nav.flag_TOW_6 = false;
}
else
{
//this page has no timing information
d_TOW_at_current_symbol = d_TOW_at_current_symbol + GALILEO_E1_CODE_PERIOD;// + GALILEO_INAV_PAGE_PART_SYMBOLS*GALILEO_E1_CODE_PERIOD;
}
}
else //if there is not a new preamble, we define the TOW of the current symbol
{
d_TOW_at_current_symbol = d_TOW_at_current_symbol + GALILEO_E1_CODE_PERIOD;
}
//if (d_flag_frame_sync == true and d_nav.flag_TOW_set==true and d_nav.flag_CRC_test == true)
if(d_nav.flag_GGTO_1 == true and d_nav.flag_GGTO_2 == true and d_nav.flag_GGTO_3 == true and d_nav.flag_GGTO_4 == true) //all GGTO parameters arrived
{
delta_t = d_nav.A_0G_10 + d_nav.A_1G_10 * (d_TOW_at_current_symbol - d_nav.t_0G_10 + 604800.0 * (fmod((d_nav.WN_0 - d_nav.WN_0G_10), 64)));
}
if(d_flag_frame_sync == true and d_nav.flag_TOW_set == true)
{
current_symbol.Flag_valid_word = true;
}
else
{
current_symbol.Flag_valid_word = false;
}
current_symbol.TOW_at_current_symbol_s = floor(d_TOW_at_current_symbol*1000.0)/1000.0;
current_symbol.TOW_at_current_symbol_s -= delta_t; //Galileo to GPS TOW
if(d_dump == true)
{
// MULTIPLEXED FILE RECORDING - Record results to file
try
{
double tmp_double;
unsigned long int tmp_ulong_int;
tmp_double = d_TOW_at_current_symbol;
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 = 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();
}
}
// remove used symbols from history
if (d_symbol_history.size() > required_symbols)
{
d_symbol_history.pop_front();
}
//3. Make the output (copy the object contents to the GNURadio reserved memory)
*out[0] = current_symbol;
//std::cout<<"GPS L1 TLM output on CH="<<this->d_channel << " SAMPLE STAMP="<<d_sample_counter/d_decimation_output_factor<<std::endl;
return 1;
}
void galileo_e1b_telemetry_decoder_cc::set_satellite(const Gnss_Satellite & satellite)
{
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;
}
void galileo_e1b_telemetry_decoder_cc::set_channel(int 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(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) << "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 trk dump file " << e.what();
}
}
}
}
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