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gnss-sdr/src/algorithms/signal_generator/gnuradio_blocks/signal_generator_c.cc

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/*!
* \file signal_generator_c.cc
* \brief GNU Radio source block that generates synthesized GNSS signal.
* \author Marc Molina, 2013. marc.molina.pena@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/>.
*
* -------------------------------------------------------------------------
*/
#include "signal_generator_c.h"
#include "GLONASS_L1_L2_CA.h"
#include "GPS_L1_CA.h"
#include "Galileo_E1.h"
#include "Galileo_E5a.h"
#include "galileo_e1_signal_processing.h"
#include "galileo_e5_signal_processing.h"
#include "glonass_l1_signal_processing.h"
#include "gps_sdr_signal_processing.h"
#include <gnuradio/io_signature.h>
#include <volk_gnsssdr/volk_gnsssdr.h>
#include <fstream>
#include <utility>
/*
* Create a new instance of signal_generator_c and return
* a boost shared_ptr. This is effectively the public constructor.
*/
signal_generator_c_sptr
signal_make_generator_c(std::vector<std::string> signal1, std::vector<std::string> system, const std::vector<unsigned int> &PRN,
const std::vector<float> &CN0_dB, const std::vector<float> &doppler_Hz,
const std::vector<unsigned int> &delay_chips, const std::vector<unsigned int> &delay_sec, bool data_flag, bool noise_flag,
unsigned int fs_in, unsigned int vector_length, float BW_BB)
{
return gnuradio::get_initial_sptr(new signal_generator_c(std::move(signal1), std::move(system), PRN, CN0_dB, doppler_Hz, delay_chips, delay_sec,
data_flag, noise_flag, fs_in, vector_length, BW_BB));
}
/*
* The private constructor
*/
signal_generator_c::signal_generator_c(std::vector<std::string> signal1,
std::vector<std::string> system,
const std::vector<unsigned int> &PRN,
std::vector<float> CN0_dB,
std::vector<float> doppler_Hz,
std::vector<unsigned int> delay_chips,
std::vector<unsigned int> delay_sec,
bool data_flag,
bool noise_flag,
unsigned int fs_in,
unsigned int vector_length,
float BW_BB) : gr::block("signal_gen_cc", gr::io_signature::make(0, 0, sizeof(gr_complex)), gr::io_signature::make(1, 1, sizeof(gr_complex) * vector_length)),
signal_(std::move(signal1)),
system_(std::move(system)),
PRN_(PRN),
CN0_dB_(std::move(CN0_dB)),
doppler_Hz_(std::move(doppler_Hz)),
delay_chips_(std::move(delay_chips)),
delay_sec_(std::move(delay_sec)),
data_flag_(data_flag),
noise_flag_(noise_flag),
fs_in_(fs_in),
num_sats_(PRN.size()),
vector_length_(vector_length),
BW_BB_(BW_BB * static_cast<float>(fs_in) / 2.0)
{
init();
generate_codes();
}
void signal_generator_c::init()
{
work_counter_ = 0;
complex_phase_ = static_cast<gr_complex *>(volk_gnsssdr_malloc(vector_length_ * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
// True if Galileo satellites are present
bool galileo_signal = std::find(system_.begin(), system_.end(), "E") != system_.end();
for (unsigned int sat = 0; sat < num_sats_; sat++)
{
start_phase_rad_.push_back(0);
current_data_bit_int_.push_back(1);
current_data_bits_.emplace_back(1, 0);
ms_counter_.push_back(0);
data_modulation_.push_back((GALILEO_E5A_I_SECONDARY_CODE.at(0) == '0' ? 1 : -1));
pilot_modulation_.push_back((GALILEO_E5A_Q_SECONDARY_CODE[PRN_[sat]].at(0) == '0' ? 1 : -1));
if (system_[sat] == "G")
{
samples_per_code_.push_back(round(static_cast<float>(fs_in_) / (GPS_L1_CA_CODE_RATE_HZ / GPS_L1_CA_CODE_LENGTH_CHIPS)));
num_of_codes_per_vector_.push_back(galileo_signal ? 4 * static_cast<int>(GALILEO_E1_C_SECONDARY_CODE_LENGTH) : 1);
data_bit_duration_ms_.push_back(1e3 / GPS_CA_TELEMETRY_RATE_BITS_SECOND);
}
else if (system_[sat] == "R")
{
samples_per_code_.push_back(round(static_cast<float>(fs_in_) / (GLONASS_L1_CA_CODE_RATE_HZ / GLONASS_L1_CA_CODE_LENGTH_CHIPS)));
num_of_codes_per_vector_.push_back(galileo_signal ? 4 * static_cast<int>(GALILEO_E1_C_SECONDARY_CODE_LENGTH) : 1);
data_bit_duration_ms_.push_back(1e3 / GLONASS_GNAV_TELEMETRY_RATE_BITS_SECOND);
}
else if (system_[sat] == "E")
{
if (signal_[sat].at(0) == '5')
{
int codelen = static_cast<int>(GALILEO_E5A_CODE_LENGTH_CHIPS);
samples_per_code_.push_back(round(static_cast<float>(fs_in_) / (GALILEO_E5A_CODE_CHIP_RATE_HZ / codelen)));
num_of_codes_per_vector_.push_back(1);
data_bit_duration_ms_.push_back(1e3 / GALILEO_E5A_SYMBOL_RATE_BPS);
}
else
{
samples_per_code_.push_back(round(static_cast<float>(fs_in_) / (GALILEO_E1_CODE_CHIP_RATE_HZ / GALILEO_E1_B_CODE_LENGTH_CHIPS)));
num_of_codes_per_vector_.push_back(static_cast<int>(GALILEO_E1_C_SECONDARY_CODE_LENGTH));
data_bit_duration_ms_.push_back(1e3 / GALILEO_E1_B_SYMBOL_RATE_BPS);
}
}
}
std::default_random_engine e1(r());
std::default_random_engine e2(r());
std::uniform_int_distribution<int> uniform_dist(0, RAND_MAX);
}
void signal_generator_c::generate_codes()
{
sampled_code_data_.reset(new gr_complex *[num_sats_]);
sampled_code_pilot_.reset(new gr_complex *[num_sats_]);
for (unsigned int sat = 0; sat < num_sats_; sat++)
{
sampled_code_data_[sat] = static_cast<gr_complex *>(std::malloc(vector_length_ * sizeof(gr_complex)));
gr_complex code[64000]; //[samples_per_code_[sat]];
if (system_[sat] == "G")
{
// Generate one code-period of 1C signal
gps_l1_ca_code_gen_complex_sampled(code, PRN_[sat], fs_in_,
static_cast<int>(GPS_L1_CA_CODE_LENGTH_CHIPS) - delay_chips_[sat]);
// Obtain the desired CN0 assuming that Pn = 1.
if (noise_flag_)
{
for (unsigned int i = 0; i < samples_per_code_[sat]; i++)
{
code[i] *= sqrt(pow(10, CN0_dB_[sat] / 10) / BW_BB_);
}
}
// Concatenate "num_of_codes_per_vector_" codes
for (unsigned int i = 0; i < num_of_codes_per_vector_[sat]; i++)
{
memcpy(&(sampled_code_data_[sat][i * samples_per_code_[sat]]),
code, sizeof(gr_complex) * samples_per_code_[sat]);
}
}
else if (system_[sat] == "R")
{
// Generate one code-period of 1G signal
glonass_l1_ca_code_gen_complex_sampled(code, /*PRN_[sat],*/ fs_in_,
static_cast<int>(GLONASS_L1_CA_CODE_LENGTH_CHIPS) - delay_chips_[sat]);
// Obtain the desired CN0 assuming that Pn = 1.
if (noise_flag_)
{
for (unsigned int i = 0; i < samples_per_code_[sat]; i++)
{
code[i] *= sqrt(pow(10, CN0_dB_[sat] / 10) / BW_BB_);
}
}
// Concatenate "num_of_codes_per_vector_" codes
for (unsigned int i = 0; i < num_of_codes_per_vector_[sat]; i++)
{
memcpy(&(sampled_code_data_[sat][i * samples_per_code_[sat]]),
code, sizeof(gr_complex) * samples_per_code_[sat]);
}
}
else if (system_[sat] == "E")
{
if (signal_[sat].at(0) == '5')
{
char signal[3];
strcpy(signal, "5X");
galileo_e5_a_code_gen_complex_sampled(sampled_code_data_[sat], signal, PRN_[sat], fs_in_,
static_cast<int>(GALILEO_E5A_CODE_LENGTH_CHIPS) - delay_chips_[sat]);
//noise
if (noise_flag_)
{
for (unsigned int i = 0; i < vector_length_; i++)
{
sampled_code_data_[sat][i] *= sqrt(pow(10, CN0_dB_[sat] / 10) / BW_BB_ / 2);
}
}
}
else
{
// Generate one code-period of E1B signal
bool cboc = true;
char signal[3];
strcpy(signal, "1B");
galileo_e1_code_gen_complex_sampled(code, signal, cboc, PRN_[sat], fs_in_,
static_cast<int>(GALILEO_E1_B_CODE_LENGTH_CHIPS) - delay_chips_[sat]);
// Obtain the desired CN0 assuming that Pn = 1.
if (noise_flag_)
{
for (unsigned int i = 0; i < samples_per_code_[sat]; i++)
{
code[i] *= sqrt(pow(10, CN0_dB_[sat] / 10) / BW_BB_ / 2);
}
}
// Concatenate "num_of_codes_per_vector_" codes
for (unsigned int i = 0; i < num_of_codes_per_vector_[sat]; i++)
{
memcpy(&(sampled_code_data_[sat][i * samples_per_code_[sat]]),
code, sizeof(gr_complex) * samples_per_code_[sat]);
}
// Generate E1C signal (25 code-periods, with secondary code)
sampled_code_pilot_[sat] = static_cast<gr_complex *>(std::malloc(vector_length_ * sizeof(gr_complex)));
strcpy(signal, "1C");
galileo_e1_code_gen_complex_sampled(sampled_code_pilot_[sat], signal, cboc, PRN_[sat], fs_in_,
static_cast<int>(GALILEO_E1_B_CODE_LENGTH_CHIPS) - delay_chips_[sat], true);
// Obtain the desired CN0 assuming that Pn = 1.
if (noise_flag_)
{
for (unsigned int i = 0; i < vector_length_; i++)
{
sampled_code_pilot_[sat][i] *= sqrt(pow(10, CN0_dB_[sat] / 10) / BW_BB_ / 2);
}
}
}
}
}
}
signal_generator_c::~signal_generator_c()
{
/* for (unsigned int sat = 0; sat < num_sats_; sat++)
{
std::free(sampled_code_data_[sat]);
if (system_[sat] == "E" && signal_[sat].at(0) != '5')
{
std::free(sampled_code_pilot_[sat]);
}
} */
volk_gnsssdr_free(complex_phase_);
}
int signal_generator_c::general_work(int noutput_items __attribute__((unused)),
gr_vector_int &ninput_items __attribute__((unused)),
gr_vector_const_void_star &input_items __attribute__((unused)),
gr_vector_void_star &output_items)
{
auto *out = reinterpret_cast<gr_complex *>(output_items[0]);
work_counter_++;
unsigned int out_idx = 0;
unsigned int i = 0;
unsigned int k = 0;
// the intermediate frequency must be set by the user
unsigned int freq = 4e6;
for (out_idx = 0; out_idx < vector_length_; out_idx++)
{
out[out_idx] = gr_complex(0.0, 0.0);
}
for (unsigned int sat = 0; sat < num_sats_; sat++)
{
float phase_step_rad = -static_cast<float>(GPS_TWO_PI) * doppler_Hz_[sat] / static_cast<float>(fs_in_);
float _phase[1];
_phase[0] = -start_phase_rad_[sat];
volk_gnsssdr_s32f_sincos_32fc(complex_phase_, -phase_step_rad, _phase, vector_length_);
start_phase_rad_[sat] += vector_length_ * phase_step_rad;
out_idx = 0;
if (system_[sat] == "G")
{
unsigned int delay_samples = (delay_chips_[sat] % static_cast<int>(GPS_L1_CA_CODE_LENGTH_CHIPS)) * samples_per_code_[sat] / GPS_L1_CA_CODE_LENGTH_CHIPS;
for (i = 0; i < num_of_codes_per_vector_[sat]; i++)
{
for (k = 0; k < delay_samples; k++)
{
out[out_idx] += sampled_code_data_[sat][out_idx] * current_data_bits_[sat] * complex_phase_[out_idx];
out_idx++;
}
if (ms_counter_[sat] == 0 && data_flag_)
{
// New random data bit
current_data_bits_[sat] = gr_complex((uniform_dist(e1) % 2) == 0 ? 1 : -1, 0);
}
for (k = delay_samples; k < samples_per_code_[sat]; k++)
{
out[out_idx] += sampled_code_data_[sat][out_idx] * current_data_bits_[sat] * complex_phase_[out_idx];
out_idx++;
}
ms_counter_[sat] = (ms_counter_[sat] + static_cast<int>(round(1e3 * GPS_L1_CA_CODE_PERIOD))) % data_bit_duration_ms_[sat];
}
}
else if (system_[sat] == "R")
{
phase_step_rad = -static_cast<float>(GPS_TWO_PI) * (freq + (DFRQ1_GLO * GLONASS_PRN.at(PRN_[sat])) + doppler_Hz_[sat]) / static_cast<float>(fs_in_);
// std::cout << "sat " << PRN_[sat] << " SG - Freq = " << (freq + (DFRQ1_GLO * GLONASS_PRN.at(PRN_[sat]))) << " Doppler = " << doppler_Hz_[sat] << std::endl;
_phase[0] = -start_phase_rad_[sat];
volk_gnsssdr_s32f_sincos_32fc(complex_phase_, -phase_step_rad, _phase, vector_length_);
unsigned int delay_samples = (delay_chips_[sat] % static_cast<int>(GLONASS_L1_CA_CODE_LENGTH_CHIPS)) * samples_per_code_[sat] / GLONASS_L1_CA_CODE_LENGTH_CHIPS;
for (i = 0; i < num_of_codes_per_vector_[sat]; i++)
{
for (k = 0; k < delay_samples; k++)
{
out[out_idx] += sampled_code_data_[sat][out_idx] * current_data_bits_[sat] * complex_phase_[out_idx];
out_idx++;
}
if (ms_counter_[sat] == 0 && data_flag_)
{
// New random data bit
current_data_bits_[sat] = gr_complex((uniform_dist(e1) % 2) == 0 ? 1 : -1, 0);
}
for (k = delay_samples; k < samples_per_code_[sat]; k++)
{
out[out_idx] += sampled_code_data_[sat][out_idx] * current_data_bits_[sat] * complex_phase_[out_idx];
out_idx++;
}
ms_counter_[sat] = (ms_counter_[sat] + static_cast<int>(round(1e3 * GLONASS_L1_CA_CODE_PERIOD))) % data_bit_duration_ms_[sat];
}
}
else if (system_[sat] == "E")
{
if (signal_[sat].at(0) == '5')
{
// EACH WORK outputs 1 modulated primary code
int codelen = static_cast<int>(GALILEO_E5A_CODE_LENGTH_CHIPS);
unsigned int delay_samples = (delay_chips_[sat] % codelen) * samples_per_code_[sat] / codelen;
for (k = 0; k < delay_samples; k++)
{
out[out_idx] += (gr_complex(sampled_code_data_[sat][out_idx].real() * data_modulation_[sat],
sampled_code_data_[sat][out_idx].imag() * pilot_modulation_[sat])) *
complex_phase_[out_idx];
out_idx++;
}
if (ms_counter_[sat] % data_bit_duration_ms_[sat] == 0 && data_flag_)
{
// New random data bit
current_data_bit_int_[sat] = (uniform_dist(e1) % 2) == 0 ? 1 : -1;
}
data_modulation_[sat] = current_data_bit_int_[sat] * (GALILEO_E5A_I_SECONDARY_CODE.at((ms_counter_[sat] + delay_sec_[sat]) % 20) == '0' ? 1 : -1);
pilot_modulation_[sat] = (GALILEO_E5A_Q_SECONDARY_CODE[PRN_[sat] - 1].at((ms_counter_[sat] + delay_sec_[sat]) % 100) == '0' ? 1 : -1);
ms_counter_[sat] = ms_counter_[sat] + static_cast<int>(round(1e3 * GALILEO_E5A_CODE_PERIOD));
for (k = delay_samples; k < samples_per_code_[sat]; k++)
{
out[out_idx] += (gr_complex(sampled_code_data_[sat][out_idx].real() * data_modulation_[sat],
sampled_code_data_[sat][out_idx].imag() * pilot_modulation_[sat])) *
complex_phase_[out_idx];
out_idx++;
}
}
else
{
unsigned int delay_samples = (delay_chips_[sat] % static_cast<int>(GALILEO_E1_B_CODE_LENGTH_CHIPS)) * samples_per_code_[sat] / GALILEO_E1_B_CODE_LENGTH_CHIPS;
for (i = 0; i < num_of_codes_per_vector_[sat]; i++)
{
for (k = 0; k < delay_samples; k++)
{
out[out_idx] += (sampled_code_data_[sat][out_idx] * current_data_bits_[sat] - sampled_code_pilot_[sat][out_idx]) * complex_phase_[out_idx];
out_idx++;
}
if (ms_counter_[sat] == 0 && data_flag_)
{
// New random data bit
current_data_bits_[sat] = gr_complex((uniform_dist(e1) % 2) == 0 ? 1 : -1, 0);
}
for (k = delay_samples; k < samples_per_code_[sat]; k++)
{
out[out_idx] += (sampled_code_data_[sat][out_idx] * current_data_bits_[sat] - sampled_code_pilot_[sat][out_idx]) * complex_phase_[out_idx];
out_idx++;
}
ms_counter_[sat] = (ms_counter_[sat] + static_cast<int>(round(1e3 * GALILEO_E1_CODE_PERIOD))) % data_bit_duration_ms_[sat];
}
}
}
}
if (noise_flag_)
{
for (out_idx = 0; out_idx < vector_length_; out_idx++)
{
out[out_idx] += gr_complex(normal_dist(e1), normal_dist(e2));
}
}
// Tell runtime system how many output items we produced.
return 1;
}
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