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mirror of https://github.com/gnss-sdr/gnss-sdr synced 2024-12-14 20:20:35 +00:00

bds_b1i: trying a new way for code

This commit is contained in:
Damian Miralles 2018-12-19 10:20:12 -06:00
parent 42b506d0bb
commit 9e9b272fb2
8 changed files with 1034 additions and 449 deletions

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@ -33,9 +33,9 @@
#ifndef GNSS_SDR_BEIDOU_B1I_TELEMETRY_DECODER_H_
#define GNSS_SDR_BEIDOU_B1I_TELEMETRY_DECODER_H_
#include "beidou_b1i_telemetry_decoder_cc.h"
#include "telemetry_decoder_interface.h"
#include <string>
#include "../gnuradio_blocks/beidou_b1i_telemetry_decoder_cc_old.h"
class ConfigurationInterface;

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@ -1,12 +1,14 @@
/*!
* \file beidou_b1i_telemetry_decoder_cc.cc
* \brief Implementation of a NAV message demodulator block based on
* Kay Borre book MATLAB-based GPS receiver
* \brief Implementation of an adapter of a BEIDOU BI1 DNAV data decoder block
* to a TelemetryDecoderInterface
* \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) 2010-2018 (see AUTHORS file for a list of contributors)
* Copyright (C) 2010-2015 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
@ -24,20 +26,28 @@
* 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/>.
* along with GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#include "beidou_b1i_telemetry_decoder_cc.h"
#include "control_message_factory.h"
#include "convolutional.h"
#include "display.h"
#include "gnss_synchro.h"
#include <boost/lexical_cast.hpp>
#include <glog/logging.h>
#include <gnuradio/io_signature.h>
#include <glog/logging.h>
#include <volk_gnsssdr/volk_gnsssdr.h>
#include <iostream>
#define CRC_ERROR_LIMIT 8
using google::LogMessage;
beidou_b1i_telemetry_decoder_cc_sptr
beidou_b1i_make_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump)
{
@ -47,86 +57,94 @@ beidou_b1i_make_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump)
beidou_b1i_telemetry_decoder_cc::beidou_b1i_telemetry_decoder_cc(
const Gnss_Satellite &satellite,
bool dump) : gr::block("beidou_navigation_cc", gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)),
gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)))
bool dump) : gr::block("beidou_b1i_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());
LOG(INFO) << "Initializing BeiDou B2a Telemetry Decoding";
// Define the number of sampes per symbol. Notice that BEIDOU has 2 rates, !!!Change
//one for the navigation data and the other for the preamble information
d_samples_per_symbol = (BEIDOU_B1I_CODE_RATE_HZ / BEIDOU_B1I_CODE_LENGTH_CHIPS) / BEIDOU_B1I_SYMBOL_RATE_SPS;
d_symbols_per_preamble = BEIDOU_DNAV_PREAMBLE_LENGTH_SYMBOLS;
// set the preamble
unsigned short int preambles_bits[BEIDOU_B1I_PREAMBLE_LENGTH_BITS] = BEIDOU_DNAV_PREAMBLE;
d_samples_per_preamble = BEIDOU_DNAV_PREAMBLE_LENGTH_SYMBOLS * d_samples_per_symbol;
// preamble bits to sampled symbols
d_preambles_symbols = static_cast<int *>(volk_gnsssdr_malloc(BEIDOU_B1I_PREAMBLE_LENGTH_SYMBOLS * sizeof(int), volk_gnsssdr_get_alignment()));
int n = 0;
for (int i = 0; i < BEIDOU_B1I_PREAMBLE_LENGTH_BITS; i++)
// preamble symbols to samples
d_secondary_code_samples = static_cast<int32_t *>(volk_gnsssdr_malloc(BEIDOU_B1I_SECONDARY_CODE_LENGTH * sizeof(int32_t), volk_gnsssdr_get_alignment()));
d_preamble_samples = static_cast<int32_t *>(volk_gnsssdr_malloc(d_samples_per_preamble * sizeof(int32_t), volk_gnsssdr_get_alignment()));
d_preamble_period_samples = BEIDOU_DNAV_PREAMBLE_PERIOD_SYMBOLS*d_samples_per_symbol;
d_subframe_length_symbols = BEIDOU_DNAV_PREAMBLE_PERIOD_SYMBOLS - BEIDOU_DNAV_PREAMBLE_LENGTH_SYMBOLS;
// Setting samples of secondary code
for (int32_t i = 0; i < BEIDOU_B1I_SECONDARY_CODE_LENGTH; i++)
{
if (BEIDOU_B1I_SECONDARY_CODE.at(i) == '1')
{
d_secondary_code_samples[i] = 1;
}
else
{
d_secondary_code_samples[i] = -1;
}
}
// Setting samples of preamble code
int32_t n = 0;
for (int32_t i = 0; i < d_symbols_per_preamble; i++)
{
if (preambles_bits[i] == 1)
{
d_preambles_symbols[n] = 1;
}
else
{
d_preambles_symbols[n] = -1;
}
n++;
}
d_samples_per_symbol = 20;
d_bits_per_preamble = 11;
d_samples_per_preamble = 11 * d_samples_per_symbol;
d_required_symbols = static_cast<uint32_t>(6000) * d_samples_per_symbol + d_samples_per_preamble;
d_stat = 0;
d_symbol_accumulator = 0;
d_symbol_accumulator_counter = 0;
d_frame_bit_index = 0;
d_flag_frame_sync = false;
d_BEIDOU_frame_4bytes = 0;
d_prev_BEIDOU_frame_4bytes = 0;
d_flag_parity = false;
d_TOW_at_Preamble_ms = 0;
flag_TOW_set = false;
d_flag_preamble = false;
d_flag_new_tow_available = false;
word_number = 0;
d_channel = 0;
flag_PLL_180_deg_phase_locked = false;
d_preamble_time_samples = 0;
d_TOW_at_current_symbol_ms = 0;
d_symbol_history.resize(BEIDOU_B1I_PREAMBLE_LENGTH_BITS); // Change fixed buffer size
d_symbol_nh_history.resize(BEIDOU_B1I_SECONDARY_CODE_LENGTH); // Change fixed buffer size
d_bit_buffer.resize(30); // Change fixed buffer size
d_symbol_history.clear(); // Clear all the elements in the buffer
d_symbol_nh_history.clear();
d_bit_buffer.clear();
d_make_correlation = true;
d_symbol_counter_corr = 0;
for (int aux = 0; aux < BEIDOU_B1I_SECONDARY_CODE_LENGTH; aux++)
{
if (BEIDOU_B1I_SECONDARY_CODE[aux] == 0)
int32_t m = 0;
if (BEIDOU_DNAV_PREAMBLE.at(i) == '1')
{
bits_NH[aux] = -1.0;
for (uint32_t j = 0; j < d_samples_per_symbol; j++)
{
d_preamble_samples[n] = d_secondary_code_samples[m];
n++;
m++;
m = m % BEIDOU_B1I_SECONDARY_CODE_LENGTH;
}
}
else
{
bits_NH[aux] = 1.0;
for (uint32_t j = 0; j < d_samples_per_symbol; j++)
{
d_preamble_samples[n] = -d_secondary_code_samples[m];
n++;
m++;
m = m % BEIDOU_B1I_SECONDARY_CODE_LENGTH;
}
}
}
sync_NH = false;
new_sym = false;
d_subframe_symbols = static_cast<double *>(volk_gnsssdr_malloc(d_subframe_length_symbols * sizeof(double), volk_gnsssdr_get_alignment()));
d_required_symbols = BEIDOU_DNAV_SUBFRAME_SYMBOLS*d_samples_per_symbol;
d_sample_counter = 0;
d_stat = 0;
d_preamble_index = 0;
d_flag_frame_sync = false;
d_TOW_at_current_symbol_ms = 0;
Flag_valid_word = false;
d_CRC_error_counter = 0;
d_flag_preamble = false;
d_channel = 0;
flag_TOW_set = false;
}
beidou_b1i_telemetry_decoder_cc::~beidou_b1i_telemetry_decoder_cc()
{
volk_gnsssdr_free(d_preambles_symbols);
volk_gnsssdr_free(d_preamble_samples);
volk_gnsssdr_free(d_secondary_code_samples);
volk_gnsssdr_free(d_subframe_symbols);
if (d_dump_file.is_open() == true)
{
try
@ -140,11 +158,68 @@ beidou_b1i_telemetry_decoder_cc::~beidou_b1i_telemetry_decoder_cc()
}
}
void beidou_b1i_telemetry_decoder_cc::decode_subframe(double *frame_symbols, int32_t frame_length)
{
// 1. Transform from symbols to bits
std::string data_bits;
// we want data_bits = frame_symbols[24:24+288]
for (uint32_t ii = 0; ii < (BEIDOU_DNAV_DATA_BITS); ii++) {
data_bits.push_back( (frame_symbols[ii] > 0) ? ('1') : ('0') );
}
d_nav.subframe_decoder(data_bits);
// 3. Check operation executed correctly
if (d_nav.flag_crc_test == true)
{
LOG(INFO) << "BeiDou DNAV CRC correct in channel " << d_channel << " from satellite " << d_satellite;
}
else
{
LOG(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 << "New BEIDOU B1I DNAV message received in channel " << d_channel << ": ephemeris from satellite " << d_satellite << 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 << "New BEIDOU B1I DNAV utc model message received in channel " << d_channel << ": UTC model parameters from satellite " << d_satellite << 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 << "New BEIDOU B1I DNAV Iono message received in channel " << d_channel << ": UTC model parameters from satellite " << d_satellite << std::endl;
}
if (d_nav.have_new_almanac() == true)
{
unsigned int 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 << " in slot number " << slot_nbr;
std::cout << "New BEIDOU B1I DNAV almanac received in channel " << d_channel << " from satellite " << d_satellite << std::endl;
}
}
void beidou_b1i_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;
d_BEIDOU_FSM.i_satellite_PRN = d_satellite.get_PRN();
DLOG(INFO) << "Navigation Satellite set to " << d_satellite;
}
@ -152,8 +227,7 @@ void beidou_b1i_telemetry_decoder_cc::set_satellite(const Gnss_Satellite &satell
void beidou_b1i_telemetry_decoder_cc::set_channel(int channel)
{
d_channel = channel;
d_BEIDOU_FSM.i_channel_ID = channel;
DLOG(INFO) << "Navigation channel set to " << channel;
LOG(INFO) << "Navigation channel set to " << channel;
// ############# ENABLE DATA FILE LOG #################
if (d_dump == true)
{
@ -166,361 +240,184 @@ void beidou_b1i_telemetry_decoder_cc::set_channel(int 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();
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();
LOG(WARNING) << "channel " << d_channel << ": exception opening Beidou TLM dump file. " << e.what();
}
}
}
}
void beidou_b1i_telemetry_decoder_cc::decodebch_bi1(int *bits, int *decbits)
{
int bit, err, reg[4] = {1, 1, 1, 1};
int errind[15] = {14, 13, 10, 12, 6, 9, 4, 11, 0, 5, 7, 8, 1, 3, 2};
for (unsigned int i = 0; i < 15; i++)
{
decbits[i] = bits[i];
}
for (unsigned int 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;
}
err = errind[reg[0] + reg[1]*2 + reg[2]*4 + reg[3]*8];
if (err > 0)
{
decbits[err - 1] *= -1;
}
}
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)
{
d_BEIDOU_frame_4bytes = 0;
int bitsdec[30], bitsbch[30], first_branch[15], second_branch[15];
if (word_counter == 1)
{
for (unsigned int j = 0; j < 30; j++)
{
bitsdec[j] = d_bit_buffer->at(j);
}
}
else
{
for (unsigned int r = 0; r < 2; r++)
{
for (unsigned int c = 0; c < 15; c++)
{
bitsbch[r*15 + c] = d_bit_buffer->at(c*2 + r);
}
}
decodebch_bi1(&bitsbch[0], first_branch);
decodebch_bi1(&bitsbch[15], second_branch);
for (unsigned int j = 0; j < 11; j++)
{
bitsdec[j] = first_branch[j];
bitsdec[j + 11] = second_branch[j];
}
for (unsigned int j = 0; j < 4; j++)
{
bitsdec[j + 22] = first_branch[11 + j];
bitsdec[j + 26] = second_branch[11 + j];
}
}
for (unsigned int k = 0; k < 30 ; k++)
{
if (bitsdec[k] == 1)
{
d_BEIDOU_frame_4bytes++;
}
d_BEIDOU_frame_4bytes <<= 1;
}
d_BEIDOU_frame_4bytes >>= 1;
}
int beidou_b1i_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_ms = 0;
int corr_NH = 0;
int32_t corr_value = 0;
int32_t 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
new_sym = false;
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];
double current_time_samples = current_symbol.Tracking_sample_counter;
double current_samples_fs = current_symbol.fs;
int symbol_value = 0;
d_symbol_nh_history.push_back(current_symbol.Prompt_I); //add new symbol to the symbol queue
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);
if (d_symbol_nh_history.size() == BEIDOU_B1I_SECONDARY_CODE_LENGTH)
{
for (int i = 0; i < BEIDOU_B1I_SECONDARY_CODE_LENGTH; i++)
{
if ((bits_NH[i] * d_symbol_nh_history.at(i)) > 0.0)
{
corr_NH += 1;
}
else
{
corr_NH -= 1;
}
}
if (abs(corr_NH) == BEIDOU_B1I_SECONDARY_CODE_LENGTH)
{
sync_NH = true;
if (corr_NH > 0)
{
symbol_value = 1;
}
else
{
symbol_value = -1;
}
//std::cout << symbol_value << std::endl;
d_symbol_history.push_back(symbol_value);
new_sym = true;
d_symbol_nh_history.clear();
}
else
{
d_symbol_nh_history.pop_front();
sync_NH = false;
new_sym = false;
}
}
if ((d_symbol_history.size() >= BEIDOU_B1I_PREAMBLE_LENGTH_BITS) and (d_make_correlation or !d_flag_frame_sync))
{
//******* preamble correlation ********
for (unsigned int i = 0; i < BEIDOU_B1I_PREAMBLE_LENGTH_BITS; i++)
{
if (d_symbol_history.at(i) < 0) // symbols clipping
{
corr_value -= d_preambles_symbols[i];
}
else
{
corr_value += d_preambles_symbols[i];
}
}
//std::cout << corr_value << std::endl;
if (std::abs(corr_value) >= BEIDOU_B1I_PREAMBLE_LENGTH_BITS)
{
/* for (unsigned int i = 0; i < d_symbol_history.size() ; i++)
{
std::cout << d_symbol_history.at(i);
}
std::cout << std::endl;
*/
// std::cout << "SUCCESSFUL PREAMBLE CORRELATION" << std::endl;
d_symbol_history.clear();
d_symbol_counter_corr++;
}
}
/*if (new_sym and )
{
flag_new_cnav_frame = beidou_nav_msg_decoder_add_symbol(&d_cnav_decoder, symbol_clip, &msg, &delay);
new_sym = false;
}*/
d_flag_preamble = false;
if (d_symbol_history.size() > d_required_symbols)
{
//******* preamble correlation ********
for (int i = 0; i < d_samples_per_preamble; i++)
{
if (d_symbol_history.at(i) < 0) // symbols clipping
{
corr_value -= d_preamble_samples[i];
}
else
{
corr_value += d_preamble_samples[i];
}
}
}
//******* frame sync ******************
if (std::abs(corr_value) == BEIDOU_B1I_PREAMBLE_LENGTH_BITS)
if (d_stat == 0) //no preamble information
{
// std::cout << "FRAME SYNC" << std::endl;
//TODO: Rewrite with state machine
if (d_stat == 0)
if (abs(corr_value) >= d_samples_per_preamble)
{
// std::cout << "STATE MACHINE" << std::endl;
d_BEIDOU_FSM.Event_beidou_word_preamble();
//record the preamble sample stamp
d_preamble_time_samples = current_time_samples; // record the preamble sample stamp
DLOG(INFO) << "Preamble detection for SAT " << this->d_satellite << "current_time_samples=" << current_time_samples;
//sync the symbol to bits integrator
d_symbol_accumulator = 0;
d_symbol_accumulator_counter = 0;
d_stat = 1; // enter into frame pre-detection status
// Record the preamble sample stamp
d_preamble_index = d_sample_counter;
LOG(INFO) << "Preamble detection for BEIDOU B1I SAT " << this->d_satellite;
// Enter into frame pre-detection status
d_stat = 1;
}
else if (d_stat == 1) //check 6 seconds of preamble separation
}
else if (d_stat == 1) // possible preamble lock
{
if (abs(corr_value) >= d_samples_per_preamble)
{
// std::cout << "6 SECONDS" << std::endl;
preamble_diff_ms = std::round(((static_cast<double>(current_time_samples) - d_preamble_time_samples) / static_cast<double>(current_samples_fs)) * 1000.0);
if (std::abs(preamble_diff_ms - BEIDOU_SUBFRAME_MS) < 1)
//check preamble separation
preamble_diff = static_cast<int32_t>(d_sample_counter - d_preamble_index);
if (abs(preamble_diff - d_preamble_period_samples) == 0)
{
std::cout << "Preamble confirmation for SAT" << std::endl;
//try to decode frame
LOG(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;
}
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
{
int k = 0;
for (uint32_t i = 0; i < d_subframe_length_symbols; i++)
{
d_subframe_symbols[i] = 0;
//integrate samples into symbols
for (uint32_t m = 0; m < d_samples_per_symbol; m++)
{
// because last symbol of the preamble is just received now!
d_subframe_symbols[i] += static_cast<float>(d_secondary_code_samples[k]) * d_symbol_history.at(i * d_samples_per_symbol + d_samples_per_preamble + m);
k++;
k = k % BEIDOU_B1I_SECONDARY_CODE_LENGTH;
}
}
}
else //180 deg. inverted carrier phase PLL lock
{
int k = 0;
for (uint32_t i = 0; i < d_subframe_length_symbols; i++)
{
d_subframe_symbols[i] = 0;
//integrate samples into symbols
for (uint32_t m = 0; m < d_samples_per_symbol; m++)
{
// because last symbol of the preamble is just received now!
d_subframe_symbols[i] -= static_cast<float>(d_secondary_code_samples[k]) * d_symbol_history.at(i * d_samples_per_symbol + d_samples_per_preamble + m);
k++;
k = k % BEIDOU_B1I_SECONDARY_CODE_LENGTH;
}
}
}
DLOG(INFO) << "Preamble confirmation for SAT " << this->d_satellite;
d_BEIDOU_FSM.Event_beidou_word_preamble();
d_flag_preamble = true;
d_make_correlation = false;
d_symbol_counter_corr = 0;
d_preamble_time_samples = current_time_samples; // record the PRN start sample index associated to the preamble
//call the decoder
decode_subframe(d_frame_symbols, d_subframe_length_symbols);
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;
if (corr_value < 0)
{
flag_PLL_180_deg_phase_locked = true; // PLL is locked to opposite phase!
DLOG(INFO) << " PLL in opposite phase for Sat " << this->d_satellite.get_PRN();
}
else
{
flag_PLL_180_deg_phase_locked = false;
}
DLOG(INFO) << " Frame sync SAT " << this->d_satellite << " with preamble start at "
<< static_cast<double>(d_preamble_time_samples) / static_cast<double>(current_samples_fs) << " [s]";
DLOG(INFO) << "BeiDou DNAV frame sync found for SAT " << this->d_satellite;
}
}
d_frame_bit_index = 10;
d_symbol_history.clear();
for (int i = 0; i < BEIDOU_B1I_PREAMBLE_LENGTH_BITS; i++)
{
d_bit_buffer.push_back(d_preambles_symbols[i]);
}
word_number = 0;
}
}
else
{
d_symbol_counter_corr++;
if (d_symbol_counter_corr > (BEIDOU_SUBFRAME_MS - BEIDOU_B1I_TELEMETRY_SYMBOLS_PER_BIT))
{
d_make_correlation = true;
}
if (d_stat == 1)
{
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);
if (preamble_diff_ms > BEIDOU_SUBFRAME_MS + 1)
else
{
DLOG(INFO) << "Lost of frame sync SAT " << this->d_satellite << " preamble_diff= " << preamble_diff_ms;
d_stat = 0; //lost of frame sync
d_flag_frame_sync = false;
flag_TOW_set = false;
d_make_correlation = true;
d_symbol_counter_corr = 0;
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) << "BeiDou DNAV frame sync lost for SAT " << this->d_satellite;
d_flag_frame_sync = false;
d_stat = 0;
}
}
}
}
if (d_flag_frame_sync and new_sym)
{
// std::cout << symbol_value << std::endl;
if (flag_PLL_180_deg_phase_locked)
{
d_bit_buffer.push_back(-symbol_value);
}
else
{
d_bit_buffer.push_back(symbol_value);
}
//******* bits to words ******
d_frame_bit_index++;
if (d_frame_bit_index == 30)
{
word_number++;
beidou_b1i_telemetry_decoder_cc::decode_word(word_number, &d_bit_buffer, d_BEIDOU_frame_4bytes);
// std::cout << d_BEIDOU_frame_4bytes << std::endl;
d_bit_buffer.clear();
d_frame_bit_index = 0;
memcpy(&d_BEIDOU_FSM.d_BEIDOU_frame_4bytes, &d_BEIDOU_frame_4bytes, sizeof(char) * 4);
//d_BEIDOU_FSM.d_preamble_time_ms = d_preamble_time_seconds * 1000.0;
d_BEIDOU_FSM.Event_beidou_word_valid();
// send TLM data to PVT using asynchronous message queues
if (d_BEIDOU_FSM.d_flag_new_subframe == true)
{
/* switch (d_BEIDOU_FSM.d_subframe_ID)
{
case 3: //we have a new set of ephemeris data for the current SV
*/ if (d_BEIDOU_FSM.d_nav.satellite_validation() == true)
{
// get ephemeris object for this SV (mandatory)
std::shared_ptr<Beidou_Dnav_Ephemeris> tmp_obj = std::make_shared<Beidou_Dnav_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_Dnav_Iono> tmp_obj = std::make_shared<Beidou_Dnav_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_Dnav_Utc_Model> tmp_obj = std::make_shared<Beidou_Dnav_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;
}
}
}
// UPDATE GNSS SYNCHRO DATA
//2. Add the telemetry decoder information
if (this->d_flag_preamble == true and d_flag_new_tow_available == true)
if (this->d_flag_preamble == true and d_nav.flag_TOW_set == true)
//update TOW at the preamble instant
{
d_TOW_at_Preamble_ms = static_cast<unsigned int>(d_BEIDOU_FSM.d_nav.d_SOW +14) * 1000 ;
d_TOW_at_current_symbol_ms = d_TOW_at_Preamble_ms + static_cast<uint32_t>((d_required_symbols + 1) * BEIDOU_B1I_CODE_PERIOD_MS);
flag_TOW_set = true;
d_flag_new_tow_available = false;
if (d_nav.flag_SOW == true)
{
d_TOW_at_Preamble_ms = static_cast<uint32_t>(d_nav.d_SOW * 1000.0);
d_TOW_at_current_symbol_ms = d_TOW_at_Preamble_ms + static_cast<uint32_t>((d_required_symbols + 1) * BEIDOU_B1I_CODE_PERIOD_MS);
d_nav.flag_SOW = false;
}
else //if there is not a new preamble, we define the TOW of the current symbol
{
d_TOW_at_current_symbol_ms += static_cast<uint32_t>(BEIDOU_B1I_CODE_PERIOD_MS);;
}
}
else //if there is not a new preamble, we define the TOW of the current symbol
{
d_TOW_at_current_symbol_ms += static_cast<uint32_t>(BEIDOU_B1I_CODE_PERIOD_MS);;
}
if (d_flag_frame_sync == true and d_nav.flag_TOW_set == true)
{
current_symbol.Flag_valid_word = true;
}
else
{
d_TOW_at_current_symbol_ms += BEIDOU_B1I_CODE_PERIOD_MS;
current_symbol.Flag_valid_word = false;
}
current_symbol.PRN = this->d_satellite.get_PRN();
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)
{
@ -529,11 +426,11 @@ std::cout << " we have a new set of utc data for the current SV "<< std::endl;
{
double tmp_double;
unsigned long int tmp_ulong_int;
tmp_double = static_cast<double>(d_TOW_at_current_symbol_ms) / 1000.0;
tmp_double = d_TOW_at_current_symbol_ms;
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;
tmp_double = 0;
d_dump_file.write(reinterpret_cast<char *>(&tmp_double), sizeof(double));
}
catch (const std::ifstream::failure &e)
@ -542,6 +439,11 @@ std::cout << " we have a new set of utc data for the current SV "<< std::endl;
}
}
// remove used symbols from history
if (d_symbol_history.size() > d_required_symbols)
{
d_symbol_history.pop_front();
}
//3. Make the output (copy the object contents to the GNURadio reserved memory)
*out[0] = current_symbol;

View File

@ -1,11 +1,14 @@
/*!
* \file beidou_b1i_telemetry_decoder_cc.h
* \brief Interface of a NAV message demodulator block based on
* Kay Borre book MATLAB-based GPS receiver
* \author Sergi Segura, 2018. sergi.segura.munoz(at)gmail.com
* \brief Implementation of an adapter of a BEIDOU BI1 DNAV data decoder block
* to a TelemetryDecoderInterface
* \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) 2010-2018 (see AUTHORS file for a list of contributors)
* Copyright (C) 2010-2015 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
@ -23,7 +26,7 @@
* 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/>.
* along with GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
@ -31,36 +34,37 @@
#ifndef GNSS_SDR_BEIDOU_B1I_TELEMETRY_DECODER_CC_H
#define GNSS_SDR_BEIDOU_B1I_TELEMETRY_DECODER_CC_H
#include "beidou_b1i_subframe_fsm.h"
#include "beidou_dnav_navigation_message.h"
#include "beidou_dnav_ephemeris.h"
#include "beidou_dnav_almanac.h"
#include "beidou_dnav_utc_model.h"
#include "gnss_satellite.h"
#include "gnss_synchro.h"
#include "Beidou_B1I.h"
#include <gnuradio/block.h>
#include <fstream>
#include <string>
#include <boost/circular_buffer.hpp>
#include "Beidou_B1I.h"
class beidou_b1i_telemetry_decoder_cc;
typedef boost::shared_ptr<beidou_b1i_telemetry_decoder_cc> beidou_b1i_telemetry_decoder_cc_sptr;
beidou_b1i_telemetry_decoder_cc_sptr
beidou_b1i_make_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump);
beidou_b1i_telemetry_decoder_cc_sptr beidou_b1i_make_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump);
//!!!! edit
/*!
* \brief This class implements a block that decodes the NAV data defined in IS-GPS-200E
* \brief This class implements a block that decodes the GNAV data defined in BEIDOU ICD v5.1
* \note Code added as part of GSoC 2018 program
* \see <a href="http://russianspacesystems.ru/wp-content/uploads/2016/08/ICD_GLONASS_eng_v5.1.pdf">GLONASS ICD</a>
*
*/
class beidou_b1i_telemetry_decoder_cc : public gr::block
{
public:
~beidou_b1i_telemetry_decoder_cc();
~beidou_b1i_telemetry_decoder_cc(); //!< Class destructor
void set_satellite(const Gnss_Satellite &satellite); //!< Set satellite PRN
void set_channel(int channel);
void decode_word(int word_counter, boost::circular_buffer<signed int> *d_bit_buffer, unsigned int& d_BEIDOU_frame_4bytes);
void decodebch_bi1(int *bits, int *decbits);
unsigned int getbitu(const unsigned char *buff, int pos, int len);
void bits2byte(int *bits, int nbits, int nbin, int right, uint8_t *bin);
void set_channel(int channel); //!< Set receiver's channel
/*!
* \brief This is where all signal processing takes place
@ -70,66 +74,49 @@ public:
private:
friend beidou_b1i_telemetry_decoder_cc_sptr
beidou_b1i_make_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump);
beidou_b1i_make_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump);
beidou_b1i_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump);
bool beidou_word_parityCheck(unsigned int beidouword);
void decode_subframe(double *symbols, int32_t frame_length);
// class private vars
//!< Preamble decoding
unsigned short int d_preambles_symbols[BEIDOU_DNAV_PREAMBLE_LENGTH_SYMBOLS];
int32_t *d_preamble_samples;
int32_t *d_secondary_code_samples;
uint32_t d_samples_per_symbol;
int32_t d_symbols_per_preamble;
int32_t d_samples_per_preamble;
int32_t d_preamble_period_samples;
double *d_subframe_symbols;
uint32_t d_subframe_length_symbols;
uint32_t d_required_symbols;
int *d_preambles_symbols;
unsigned int d_stat;
bool d_flag_frame_sync;
//!< Storage for incoming data
std::deque<float> d_symbol_history;
// symbols
boost::circular_buffer<signed int> d_symbol_history;
boost::circular_buffer<signed int> d_symbol_nh_history;
boost::circular_buffer<signed int> d_bit_buffer;
//!< Variables for internal functionality
uint64_t d_sample_counter; //!< Sample counter as an index (1,2,3,..etc) indicating number of samples processed
uint64_t d_preamble_index; //!< Index of sample number where preamble was found
uint32_t d_stat; //!< Status of decoder
bool d_flag_frame_sync; //!< Indicate when a frame sync is achieved
bool d_flag_preamble; //!< Flag indicating when preamble was found
int32_t d_CRC_error_counter; //!< Number of failed CRC operations
bool flag_TOW_set; //!< Indicates when time of week is set
double d_symbol_accumulator;
short int d_symbol_accumulator_counter;
// symbol counting
bool d_make_correlation;
unsigned int d_symbol_counter_corr;
//bits and frame
unsigned short int d_frame_bit_index;
double bits_NH[BEIDOU_B1I_SECONDARY_CODE_LENGTH];
unsigned int d_BEIDOU_frame_4bytes;
unsigned int d_prev_BEIDOU_frame_4bytes;
bool d_flag_parity;
bool d_flag_preamble;
bool d_flag_new_tow_available;
int d_word_number;
uint32_t d_samples_per_symbol;
int32_t d_bits_per_preamble;
int32_t d_samples_per_preamble;
uint32_t d_required_symbols;
// navigation message vars
//!< Navigation Message variable
Beidou_Dnav_Navigation_Message d_nav;
BeidouB1iSubframeFsm d_BEIDOU_FSM;
bool d_dump;
//!< Values to populate gnss synchronization structure
uint32_t d_TOW_at_Preamble_ms;
uint32_t d_TOW_at_current_symbol_ms;
bool Flag_valid_word;
//!< Satellite Information and logging capacity
Gnss_Satellite d_satellite;
int d_channel;
unsigned long int d_preamble_time_samples;
unsigned int d_TOW_at_Preamble_ms;
unsigned int d_TOW_at_current_symbol_ms;
unsigned int word_number;
bool flag_TOW_set;
bool flag_PLL_180_deg_phase_locked;
int32_t d_channel;
bool d_dump;
std::string d_dump_filename;
std::ofstream d_dump_file;
bool sync_NH;
bool new_sym;
};
#endif

View File

@ -0,0 +1,550 @@
/*!
* \file beidou_b1i_telemetry_decoder_cc.cc
* \brief Implementation of a NAV message demodulator block based on
* Kay Borre book MATLAB-based GPS receiver
* \author Sergi Segura, 2018. sergi.segura.munoz(at)gmail.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 "beidou_b1i_telemetry_decoder_cc_old.h"
#include "control_message_factory.h"
#include <boost/lexical_cast.hpp>
#include <glog/logging.h>
#include <gnuradio/io_signature.h>
#include <volk_gnsssdr/volk_gnsssdr.h>
using google::LogMessage;
beidou_b1i_telemetry_decoder_cc_sptr
beidou_b1i_make_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump)
{
return beidou_b1i_telemetry_decoder_cc_sptr(new beidou_b1i_telemetry_decoder_cc(satellite, dump));
}
beidou_b1i_telemetry_decoder_cc::beidou_b1i_telemetry_decoder_cc(
const Gnss_Satellite &satellite,
bool dump) : gr::block("beidou_navigation_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());
// set the preamble
unsigned short int preambles_bits[BEIDOU_B1I_PREAMBLE_LENGTH_BITS] = BEIDOU_DNAV_PREAMBLE;
// preamble bits to sampled symbols
d_preambles_symbols = static_cast<int *>(volk_gnsssdr_malloc(BEIDOU_B1I_PREAMBLE_LENGTH_SYMBOLS * sizeof(int), volk_gnsssdr_get_alignment()));
int n = 0;
for (int i = 0; i < BEIDOU_B1I_PREAMBLE_LENGTH_BITS; i++)
{
if (preambles_bits[i] == 1)
{
d_preambles_symbols[n] = 1;
}
else
{
d_preambles_symbols[n] = -1;
}
n++;
}
d_samples_per_symbol = 20;
d_bits_per_preamble = 11;
d_samples_per_preamble = 11 * d_samples_per_symbol;
d_required_symbols = static_cast<uint32_t>(6000) * d_samples_per_symbol + d_samples_per_preamble;
d_stat = 0;
d_symbol_accumulator = 0;
d_symbol_accumulator_counter = 0;
d_frame_bit_index = 0;
d_flag_frame_sync = false;
d_BEIDOU_frame_4bytes = 0;
d_prev_BEIDOU_frame_4bytes = 0;
d_flag_parity = false;
d_TOW_at_Preamble_ms = 0;
flag_TOW_set = false;
d_flag_preamble = false;
d_flag_new_tow_available = false;
word_number = 0;
d_channel = 0;
flag_PLL_180_deg_phase_locked = false;
d_preamble_time_samples = 0;
d_TOW_at_current_symbol_ms = 0;
d_symbol_history.resize(BEIDOU_B1I_PREAMBLE_LENGTH_BITS); // Change fixed buffer size
d_symbol_nh_history.resize(BEIDOU_B1I_SECONDARY_CODE_LENGTH); // Change fixed buffer size
d_bit_buffer.resize(30); // Change fixed buffer size
d_symbol_history.clear(); // Clear all the elements in the buffer
d_symbol_nh_history.clear();
d_bit_buffer.clear();
d_make_correlation = true;
d_symbol_counter_corr = 0;
for (int aux = 0; aux < BEIDOU_B1I_SECONDARY_CODE_LENGTH; aux++)
{
if (BEIDOU_B1I_SECONDARY_CODE[aux] == 0)
{
bits_NH[aux] = -1.0;
}
else
{
bits_NH[aux] = 1.0;
}
}
sync_NH = false;
new_sym = false;
}
beidou_b1i_telemetry_decoder_cc::~beidou_b1i_telemetry_decoder_cc()
{
volk_gnsssdr_free(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 beidou_b1i_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;
d_BEIDOU_FSM.i_satellite_PRN = d_satellite.get_PRN();
DLOG(INFO) << "Navigation Satellite set to " << d_satellite;
}
void beidou_b1i_telemetry_decoder_cc::set_channel(int channel)
{
d_channel = channel;
d_BEIDOU_FSM.i_channel_ID = channel;
DLOG(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();
}
}
}
}
void beidou_b1i_telemetry_decoder_cc::decodebch_bi1(int *bits, int *decbits)
{
int bit, err, reg[4] = {1, 1, 1, 1};
int errind[15] = {14, 13, 10, 12, 6, 9, 4, 11, 0, 5, 7, 8, 1, 3, 2};
for (unsigned int i = 0; i < 15; i++)
{
decbits[i] = bits[i];
}
for (unsigned int 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;
}
err = errind[reg[0] + reg[1]*2 + reg[2]*4 + reg[3]*8];
if (err > 0)
{
decbits[err - 1] *= -1;
}
}
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)
{
d_BEIDOU_frame_4bytes = 0;
int bitsdec[30], bitsbch[30], first_branch[15], second_branch[15];
if (word_counter == 1)
{
for (unsigned int j = 0; j < 30; j++)
{
bitsdec[j] = d_bit_buffer->at(j);
}
}
else
{
for (unsigned int r = 0; r < 2; r++)
{
for (unsigned int c = 0; c < 15; c++)
{
bitsbch[r*15 + c] = d_bit_buffer->at(c*2 + r);
}
}
decodebch_bi1(&bitsbch[0], first_branch);
decodebch_bi1(&bitsbch[15], second_branch);
for (unsigned int j = 0; j < 11; j++)
{
bitsdec[j] = first_branch[j];
bitsdec[j + 11] = second_branch[j];
}
for (unsigned int j = 0; j < 4; j++)
{
bitsdec[j + 22] = first_branch[11 + j];
bitsdec[j + 26] = second_branch[11 + j];
}
}
for (unsigned int k = 0; k < 30 ; k++)
{
if (bitsdec[k] == 1)
{
d_BEIDOU_frame_4bytes++;
}
d_BEIDOU_frame_4bytes <<= 1;
}
d_BEIDOU_frame_4bytes >>= 1;
}
int beidou_b1i_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_ms = 0;
int corr_NH = 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
new_sym = false;
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];
double current_time_samples = current_symbol.Tracking_sample_counter;
double current_samples_fs = current_symbol.fs;
int symbol_value = 0;
d_symbol_nh_history.push_back(current_symbol.Prompt_I); //add new symbol to the symbol queue
consume_each(1);
if (d_symbol_nh_history.size() == BEIDOU_B1I_SECONDARY_CODE_LENGTH)
{
for (int i = 0; i < BEIDOU_B1I_SECONDARY_CODE_LENGTH; i++)
{
if ((bits_NH[i] * d_symbol_nh_history.at(i)) > 0.0)
{
corr_NH += 1;
}
else
{
corr_NH -= 1;
}
}
if (abs(corr_NH) == BEIDOU_B1I_SECONDARY_CODE_LENGTH)
{
sync_NH = true;
if (corr_NH > 0)
{
symbol_value = 1;
}
else
{
symbol_value = -1;
}
//std::cout << symbol_value << std::endl;
d_symbol_history.push_back(symbol_value);
new_sym = true;
d_symbol_nh_history.clear();
}
else
{
d_symbol_nh_history.pop_front();
sync_NH = false;
new_sym = false;
}
}
if ((d_symbol_history.size() >= BEIDOU_B1I_PREAMBLE_LENGTH_BITS) and (d_make_correlation or !d_flag_frame_sync))
{
//******* preamble correlation ********
for (unsigned int i = 0; i < BEIDOU_B1I_PREAMBLE_LENGTH_BITS; i++)
{
if (d_symbol_history.at(i) < 0) // symbols clipping
{
corr_value -= d_preambles_symbols[i];
}
else
{
corr_value += d_preambles_symbols[i];
}
}
//std::cout << corr_value << std::endl;
if (std::abs(corr_value) >= BEIDOU_B1I_PREAMBLE_LENGTH_BITS)
{
/* for (unsigned int i = 0; i < d_symbol_history.size() ; i++)
{
std::cout << d_symbol_history.at(i);
}
std::cout << std::endl;
*/
// std::cout << "SUCCESSFUL PREAMBLE CORRELATION" << std::endl;
d_symbol_history.clear();
d_symbol_counter_corr++;
}
}
/*if (new_sym and )
{
flag_new_cnav_frame = beidou_nav_msg_decoder_add_symbol(&d_cnav_decoder, symbol_clip, &msg, &delay);
new_sym = false;
}*/
d_flag_preamble = false;
//******* frame sync ******************
if (std::abs(corr_value) == BEIDOU_B1I_PREAMBLE_LENGTH_BITS)
{
// std::cout << "FRAME SYNC" << std::endl;
//TODO: Rewrite with state machine
if (d_stat == 0)
{
// std::cout << "STATE MACHINE" << std::endl;
d_BEIDOU_FSM.Event_beidou_word_preamble();
//record the preamble sample stamp
d_preamble_time_samples = current_time_samples; // record the preamble sample stamp
DLOG(INFO) << "Preamble detection for SAT " << this->d_satellite << "current_time_samples=" << current_time_samples;
//sync the symbol to bits integrator
d_symbol_accumulator = 0;
d_symbol_accumulator_counter = 0;
d_stat = 1; // enter into frame pre-detection status
}
else if (d_stat == 1) //check 6 seconds of preamble separation
{
// std::cout << "6 SECONDS" << std::endl;
preamble_diff_ms = std::round(((static_cast<double>(current_time_samples) - d_preamble_time_samples) / static_cast<double>(current_samples_fs)) * 1000.0);
if (std::abs(preamble_diff_ms - BEIDOU_SUBFRAME_MS) < 1)
{
std::cout << "Preamble confirmation for SAT" << std::endl;
DLOG(INFO) << "Preamble confirmation for SAT " << this->d_satellite;
d_BEIDOU_FSM.Event_beidou_word_preamble();
d_flag_preamble = true;
d_make_correlation = false;
d_symbol_counter_corr = 0;
d_preamble_time_samples = current_time_samples; // record the PRN start sample index associated to the preamble
if (!d_flag_frame_sync)
{
d_flag_frame_sync = true;
if (corr_value < 0)
{
flag_PLL_180_deg_phase_locked = true; // PLL is locked to opposite phase!
DLOG(INFO) << " PLL in opposite phase for Sat " << this->d_satellite.get_PRN();
}
else
{
flag_PLL_180_deg_phase_locked = false;
}
DLOG(INFO) << " Frame sync SAT " << this->d_satellite << " with preamble start at "
<< static_cast<double>(d_preamble_time_samples) / static_cast<double>(current_samples_fs) << " [s]";
}
}
d_frame_bit_index = 10;
d_symbol_history.clear();
for (int i = 0; i < BEIDOU_B1I_PREAMBLE_LENGTH_BITS; i++)
{
d_bit_buffer.push_back(d_preambles_symbols[i]);
}
word_number = 0;
}
}
else
{
d_symbol_counter_corr++;
if (d_symbol_counter_corr > (BEIDOU_SUBFRAME_MS - BEIDOU_B1I_TELEMETRY_SYMBOLS_PER_BIT))
{
d_make_correlation = true;
}
if (d_stat == 1)
{
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);
if (preamble_diff_ms > BEIDOU_SUBFRAME_MS + 1)
{
DLOG(INFO) << "Lost of frame sync SAT " << this->d_satellite << " preamble_diff= " << preamble_diff_ms;
d_stat = 0; //lost of frame sync
d_flag_frame_sync = false;
flag_TOW_set = false;
d_make_correlation = true;
d_symbol_counter_corr = 0;
}
}
}
if (d_flag_frame_sync and new_sym)
{
// std::cout << symbol_value << std::endl;
if (flag_PLL_180_deg_phase_locked)
{
d_bit_buffer.push_back(-symbol_value);
}
else
{
d_bit_buffer.push_back(symbol_value);
}
//******* bits to words ******
d_frame_bit_index++;
if (d_frame_bit_index == 30)
{
word_number++;
beidou_b1i_telemetry_decoder_cc::decode_word(word_number, &d_bit_buffer, d_BEIDOU_frame_4bytes);
// std::cout << d_BEIDOU_frame_4bytes << std::endl;
d_bit_buffer.clear();
d_frame_bit_index = 0;
memcpy(&d_BEIDOU_FSM.d_BEIDOU_frame_4bytes, &d_BEIDOU_frame_4bytes, sizeof(char) * 4);
//d_BEIDOU_FSM.d_preamble_time_ms = d_preamble_time_seconds * 1000.0;
d_BEIDOU_FSM.Event_beidou_word_valid();
// send TLM data to PVT using asynchronous message queues
if (d_BEIDOU_FSM.d_flag_new_subframe == true)
{
/* switch (d_BEIDOU_FSM.d_subframe_ID)
{
case 3: //we have a new set of ephemeris data for the current SV
*/ if (d_BEIDOU_FSM.d_nav.satellite_validation() == true)
{
// get ephemeris object for this SV (mandatory)
std::shared_ptr<Beidou_Dnav_Ephemeris> tmp_obj = std::make_shared<Beidou_Dnav_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_Dnav_Iono> tmp_obj = std::make_shared<Beidou_Dnav_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_Dnav_Utc_Model> tmp_obj = std::make_shared<Beidou_Dnav_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_Preamble_ms = static_cast<unsigned int>(d_BEIDOU_FSM.d_nav.d_SOW +14) * 1000 ;
d_TOW_at_current_symbol_ms = d_TOW_at_Preamble_ms + static_cast<uint32_t>((d_required_symbols + 1) * BEIDOU_B1I_CODE_PERIOD_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;
}

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@ -0,0 +1,135 @@
/*!
* \file beidou_b1i_telemetry_decoder_cc.h
* \brief Interface of a NAV message demodulator block based on
* Kay Borre book MATLAB-based GPS receiver
* \author Sergi Segura, 2018. sergi.segura.munoz(at)gmail.com
* -------------------------------------------------------------------------
*
* 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/>.
*
* -------------------------------------------------------------------------
*/
#ifndef GNSS_SDR_BEIDOU_B1I_TELEMETRY_DECODER_CC_H
#define GNSS_SDR_BEIDOU_B1I_TELEMETRY_DECODER_CC_H
#include "beidou_b1i_subframe_fsm.h"
#include "gnss_satellite.h"
#include "gnss_synchro.h"
#include <gnuradio/block.h>
#include <fstream>
#include <string>
#include <boost/circular_buffer.hpp>
#include "Beidou_B1I.h"
class beidou_b1i_telemetry_decoder_cc;
typedef boost::shared_ptr<beidou_b1i_telemetry_decoder_cc> beidou_b1i_telemetry_decoder_cc_sptr;
beidou_b1i_telemetry_decoder_cc_sptr
beidou_b1i_make_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump);
/*!
* \brief This class implements a block that decodes the NAV data defined in IS-GPS-200E
*
*/
class beidou_b1i_telemetry_decoder_cc : public gr::block
{
public:
~beidou_b1i_telemetry_decoder_cc();
void set_satellite(const Gnss_Satellite &satellite); //!< Set satellite PRN
void set_channel(int channel);
void decode_word(int word_counter, boost::circular_buffer<signed int> *d_bit_buffer, unsigned int& d_BEIDOU_frame_4bytes);
void decodebch_bi1(int *bits, int *decbits);
unsigned int getbitu(const unsigned char *buff, int pos, int len);
void bits2byte(int *bits, int nbits, int nbin, int right, uint8_t *bin);
/*!
* \brief This is where all signal processing takes place
*/
int general_work(int noutput_items, gr_vector_int &ninput_items,
gr_vector_const_void_star &input_items, gr_vector_void_star &output_items);
private:
friend beidou_b1i_telemetry_decoder_cc_sptr
beidou_b1i_make_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump);
beidou_b1i_telemetry_decoder_cc(const Gnss_Satellite &satellite, bool dump);
bool beidou_word_parityCheck(unsigned int beidouword);
// class private vars
int *d_preambles_symbols;
unsigned int d_stat;
bool d_flag_frame_sync;
// symbols
boost::circular_buffer<signed int> d_symbol_history;
boost::circular_buffer<signed int> d_symbol_nh_history;
boost::circular_buffer<signed int> d_bit_buffer;
double d_symbol_accumulator;
short int d_symbol_accumulator_counter;
// symbol counting
bool d_make_correlation;
unsigned int d_symbol_counter_corr;
//bits and frame
unsigned short int d_frame_bit_index;
double bits_NH[BEIDOU_B1I_SECONDARY_CODE_LENGTH];
unsigned int d_BEIDOU_frame_4bytes;
unsigned int d_prev_BEIDOU_frame_4bytes;
bool d_flag_parity;
bool d_flag_preamble;
bool d_flag_new_tow_available;
int d_word_number;
uint32_t d_samples_per_symbol;
int32_t d_bits_per_preamble;
int32_t d_samples_per_preamble;
uint32_t d_required_symbols;
// navigation message vars
Beidou_Dnav_Navigation_Message d_nav;
BeidouB1iSubframeFsm d_BEIDOU_FSM;
bool d_dump;
Gnss_Satellite d_satellite;
int d_channel;
unsigned long int d_preamble_time_samples;
unsigned int d_TOW_at_Preamble_ms;
unsigned int d_TOW_at_current_symbol_ms;
unsigned int word_number;
bool flag_TOW_set;
bool flag_PLL_180_deg_phase_locked;
std::string d_dump_filename;
std::ofstream d_dump_file;
bool sync_NH;
bool new_sym;
};
#endif

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@ -54,7 +54,7 @@ const double BEIDOU_B1I_CODE_PERIOD = 0.001; //!< beidou b1I code p
const unsigned int BEIDOU_B1I_CODE_PERIOD_MS = 1; //!< GPS L1 C/A code period [ms]
const double BEIDOU_B1I_CHIP_PERIOD = 4.8875e-07; //!< beidou b1I chip period [seconds]
const int BEIDOU_B1I_SECONDARY_CODE_LENGTH = 20;
const int BEIDOU_B1I_SECONDARY_CODE[20] = {0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 0};
const std::string BEIDOU_B1I_SECONDARY_CODE = "00000100110101001110";
const std::string BEIDOU_B1I_SECONDARY_CODE_STR = "00000100110101001110";
/*!
@ -75,7 +75,7 @@ const double BEIDOU_STARTOFFSET_ms = 68.802; //**************[ms] Initial sign.
const int BEIDOU_B1I_HISTORY_DEEP = 100; // ****************
// NAVIGATION MESSAGE DEMODULATION AND DECODING
#define BEIDOU_DNAV_PREAMBLE {1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0}
const int BEIDOU_B1I_PREAMBLE_LENGTH_BITS = 11;
const int BEIDOU_B1I_PREAMBLE_LENGTH_SYMBOLS = 220; // **************
const double BEIDOU_B1I_PREAMBLE_DURATION_S = 0.220;
@ -90,8 +90,15 @@ const int BEIDOU_SUBFRAME_SECONDS = 6; //!< Subframe duration [s
const int BEIDOU_SUBFRAME_MS = 6000; //!< Subframe duration [miliseconds]
const int BEIDOU_WORD_BITS = 30; //!< Number of bits per word in the NAV message [bits]
const std::string BEIDOU_DNAV_PREAMBLE = "11100010010";
const int BEIDOU_DNAV_PREAMBLE_LENGTH_BITS = 11;
const int BEIDOU_DNAV_PREAMBLE_LENGTH_SYMBOLS = 220; // **************
const int BEIDOU_DNAV_PREAMBLE_LENGTH_SYMBOLS = 11; // **************
const double BEIDOU_DNAV_PREAMBLE_PERIOD_SYMBOLS = 300;
const double BEIDOU_DNAV_SUBFRAME_SYMBOLS = 300;
const double BEIDOU_DNAV_DATA_BITS = 300;
const double BEIDOU_B1I_SYMBOL_RATE_SPS = 50; //BEIDOU symbol rate
const double BEIDOU_B1I_PREAMBLE_PERIOD_SYMBOLS = 300;
// BEIDOU D1 NAVIGATION MESSAGE STRUCTURE
// GENERAL

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@ -848,9 +848,6 @@ Beidou_Dnav_Ephemeris Beidou_Dnav_Navigation_Message::get_ephemeris()
ephemeris.d_TGD1 = d_TGD1;
ephemeris.d_AODC = d_AODC;
ephemeris.d_AODE = d_AODE;
//ephemeris.d_AODE_SF2 = d_AODE_SF2;
//ephemeris.d_AODE_SF3 = d_AODE_SF3;
//ephemeris.i_AODO = i_AODO;
ephemeris.b_fit_interval_flag = b_fit_interval_flag;
ephemeris.d_spare1 = d_spare1;
ephemeris.d_spare2 = d_spare2;

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@ -69,6 +69,13 @@ private:
public:
bool b_valid_ephemeris_set_flag; // flag indicating that this ephemeris set have passed the validation check
bool flag_sf_1;
bool flag_sf_2;
bool flag_sf_3;
bool flag_sf_4;
bool flag_sf_5;
bool flag_SOW;
//broadcast orbit 1
double d_SOW; //!< Time of BeiDou Week of the ephemeris set (taken from subframes SOW) [s]
double d_SOW_SF1; //!< Time of BeiDou Week from HOW word of Subframe 1 [s]