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gnss-sdr/src/algorithms/libs/galileo_e5_signal_replica.cc
Carles Fernandez 7308745f05
Apply more concise file header format 
Re-license CMake scripts with BSD-3-Clause
2020-12-30 13:35:06 +01:00

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/*!
* \file galileo_e5_signal_replica.cc
* \brief This library implements various functions for Galileo E5 signal
* replica generation
* \author Marc Sales, 2014. marcsales92(at)gmail.com
* \author Piyush Gupta, 2020. piyush04111999@gmail.com
* \note Code added as part of GSoc 2020 Program.
*
*
* -----------------------------------------------------------------------------
*
* GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
* This file is part of GNSS-SDR.
*
* Copyright (C) 2010-2020 (see AUTHORS file for a list of contributors)
* SPDX-License-Identifier: GPL-3.0-or-later
*
* -----------------------------------------------------------------------------
*/
#include "galileo_e5_signal_replica.h"
#include "Galileo_E5a.h"
#include "Galileo_E5b.h"
#include "gnss_signal_replica.h"
#include <gnuradio/gr_complex.h>
#include <memory>
#include <utility>
#include <vector>
void galileo_e5_a_code_gen_complex_primary(own::span<std::complex<float>> dest,
int32_t prn,
const std::array<char, 3>& signal_id)
{
const uint32_t prn_ = prn - 1;
uint32_t index = 0;
std::array<int32_t, 4> a{};
if ((prn < 1) || (prn > 50))
{
return;
}
if (signal_id[0] == '5' && signal_id[1] == 'Q')
{
for (size_t i = 0; i < GALILEO_E5A_Q_PRIMARY_CODE_STR_LENGTH - 1; i++)
{
hex_to_binary_converter(a, GALILEO_E5A_Q_PRIMARY_CODE[prn_][i]);
dest[index] = std::complex<float>(static_cast<float>(a[0]), 0.0);
dest[index + 1] = std::complex<float>(static_cast<float>(a[1]), 0.0);
dest[index + 2] = std::complex<float>(static_cast<float>(a[2]), 0.0);
dest[index + 3] = std::complex<float>(static_cast<float>(a[3]), 0.0);
index = index + 4;
}
// last 2 bits are filled up zeros
hex_to_binary_converter(a, GALILEO_E5A_Q_PRIMARY_CODE[prn_][GALILEO_E5A_Q_PRIMARY_CODE_STR_LENGTH - 1]);
dest[index] = std::complex<float>(static_cast<float>(a[0]), 0.0);
dest[index + 1] = std::complex<float>(static_cast<float>(a[1]), 0.0);
}
else if (signal_id[0] == '5' && signal_id[1] == 'I')
{
for (size_t i = 0; i < GALILEO_E5A_I_PRIMARY_CODE_STR_LENGTH - 1; i++)
{
hex_to_binary_converter(a, GALILEO_E5A_I_PRIMARY_CODE[prn_][i]);
dest[index] = std::complex<float>(static_cast<float>(a[0]), 0.0);
dest[index + 1] = std::complex<float>(static_cast<float>(a[1]), 0.0);
dest[index + 2] = std::complex<float>(static_cast<float>(a[2]), 0.0);
dest[index + 3] = std::complex<float>(static_cast<float>(a[3]), 0.0);
index = index + 4;
}
// last 2 bits are filled up zeros
hex_to_binary_converter(a, GALILEO_E5A_I_PRIMARY_CODE[prn_][GALILEO_E5A_I_PRIMARY_CODE_STR_LENGTH - 1]);
dest[index] = std::complex<float>(static_cast<float>(a[0]), 0.0);
dest[index + 1] = std::complex<float>(static_cast<float>(a[1]), 0.0);
}
else if (signal_id[0] == '5' && signal_id[1] == 'X')
{
std::array<int32_t, 4> b{};
for (size_t i = 0; i < GALILEO_E5A_I_PRIMARY_CODE_STR_LENGTH - 1; i++)
{
hex_to_binary_converter(a, GALILEO_E5A_I_PRIMARY_CODE[prn_][i]);
hex_to_binary_converter(b, GALILEO_E5A_Q_PRIMARY_CODE[prn_][i]);
dest[index] = std::complex<float>(static_cast<float>(a[0]), static_cast<float>(b[0]));
dest[index + 1] = std::complex<float>(static_cast<float>(a[1]), static_cast<float>(b[1]));
dest[index + 2] = std::complex<float>(static_cast<float>(a[2]), static_cast<float>(b[2]));
dest[index + 3] = std::complex<float>(static_cast<float>(a[3]), static_cast<float>(b[3]));
index = index + 4;
}
// last 2 bits are filled up zeros
hex_to_binary_converter(a, GALILEO_E5A_I_PRIMARY_CODE[prn_][GALILEO_E5A_I_PRIMARY_CODE_STR_LENGTH - 1]);
hex_to_binary_converter(b, GALILEO_E5A_Q_PRIMARY_CODE[prn_][GALILEO_E5A_Q_PRIMARY_CODE_STR_LENGTH - 1]);
dest[index] = std::complex<float>(static_cast<float>(a[0]), static_cast<float>(b[0]));
dest[index + 1] = std::complex<float>(static_cast<float>(a[1]), static_cast<float>(b[1]));
}
}
void galileo_e5_a_code_gen_complex_sampled(own::span<std::complex<float>> dest,
uint32_t prn,
const std::array<char, 3>& signal_id,
int32_t sampling_freq,
uint32_t chip_shift)
{
constexpr uint32_t codeLength = GALILEO_E5A_CODE_LENGTH_CHIPS;
constexpr int32_t codeFreqBasis = GALILEO_E5A_CODE_CHIP_RATE_CPS;
const auto samplesPerCode = static_cast<uint32_t>(static_cast<double>(sampling_freq) / (static_cast<double>(codeFreqBasis) / static_cast<double>(codeLength)));
const uint32_t delay = ((codeLength - chip_shift) % codeLength) * samplesPerCode / codeLength;
std::vector<std::complex<float>> code_aux(codeLength);
galileo_e5_a_code_gen_complex_primary(code_aux, prn, signal_id);
if (sampling_freq != codeFreqBasis)
{
std::vector<std::complex<float>> resampled_signal_aux(samplesPerCode);
resampler(code_aux, resampled_signal_aux, codeFreqBasis, sampling_freq); // resamples code to sampling_freq
code_aux = std::move(resampled_signal_aux);
}
for (uint32_t i = 0; i < samplesPerCode; i++)
{
dest[(i + delay) % samplesPerCode] = code_aux[i];
}
}
void galileo_e5_b_code_gen_complex_primary(own::span<std::complex<float>> dest,
int32_t prn,
const std::array<char, 3>& signal_id)
{
const uint32_t prn_ = prn - 1;
uint32_t index = 0;
std::array<int32_t, 4> a{};
if ((prn < 1) || (prn > 50))
{
return;
}
if (signal_id[0] == '7' && signal_id[1] == 'Q')
{
for (size_t i = 0; i < GALILEO_E5B_Q_PRIMARY_CODE_STR_LENGTH - 1; i++)
{
hex_to_binary_converter(a, GALILEO_E5B_Q_PRIMARY_CODE[prn_][i]);
dest[index] = std::complex<float>(static_cast<float>(a[0]), 0.0);
dest[index + 1] = std::complex<float>(static_cast<float>(a[1]), 0.0);
dest[index + 2] = std::complex<float>(static_cast<float>(a[2]), 0.0);
dest[index + 3] = std::complex<float>(static_cast<float>(a[3]), 0.0);
index = index + 4;
}
// last 2 bits are filled up zeros
hex_to_binary_converter(a, GALILEO_E5B_Q_PRIMARY_CODE[prn_][GALILEO_E5B_Q_PRIMARY_CODE_STR_LENGTH - 1]);
dest[index] = std::complex<float>(static_cast<float>(a[0]), 0.0);
dest[index + 1] = std::complex<float>(static_cast<float>(a[1]), 0.0);
}
else if (signal_id[0] == '7' && signal_id[1] == 'I')
{
for (size_t i = 0; i < GALILEO_E5B_I_PRIMARY_CODE_STR_LENGTH - 1; i++)
{
hex_to_binary_converter(a, GALILEO_E5B_I_PRIMARY_CODE[prn_][i]);
dest[index] = std::complex<float>(static_cast<float>(a[0]), 0.0);
dest[index + 1] = std::complex<float>(static_cast<float>(a[1]), 0.0);
dest[index + 2] = std::complex<float>(static_cast<float>(a[2]), 0.0);
dest[index + 3] = std::complex<float>(static_cast<float>(a[3]), 0.0);
index = index + 4;
}
// last 2 bits are filled up zeros
hex_to_binary_converter(a, GALILEO_E5B_I_PRIMARY_CODE[prn_][GALILEO_E5B_I_PRIMARY_CODE_STR_LENGTH - 1]);
dest[index] = std::complex<float>(static_cast<float>(a[0]), 0.0);
dest[index + 1] = std::complex<float>(static_cast<float>(a[1]), 0.0);
}
else if (signal_id[0] == '7' && signal_id[1] == 'X')
{
std::array<int32_t, 4> b{};
for (size_t i = 0; i < GALILEO_E5B_I_PRIMARY_CODE_STR_LENGTH - 1; i++)
{
hex_to_binary_converter(a, GALILEO_E5B_I_PRIMARY_CODE[prn_][i]);
hex_to_binary_converter(b, GALILEO_E5B_Q_PRIMARY_CODE[prn_][i]);
dest[index] = std::complex<float>(static_cast<float>(a[0]), static_cast<float>(b[0]));
dest[index + 1] = std::complex<float>(static_cast<float>(a[1]), static_cast<float>(b[1]));
dest[index + 2] = std::complex<float>(static_cast<float>(a[2]), static_cast<float>(b[2]));
dest[index + 3] = std::complex<float>(static_cast<float>(a[3]), static_cast<float>(b[3]));
index = index + 4;
}
// last 2 bits are filled up zeros
hex_to_binary_converter(a, GALILEO_E5B_I_PRIMARY_CODE[prn_][GALILEO_E5B_I_PRIMARY_CODE_STR_LENGTH - 1]);
hex_to_binary_converter(b, GALILEO_E5B_Q_PRIMARY_CODE[prn_][GALILEO_E5B_Q_PRIMARY_CODE_STR_LENGTH - 1]);
dest[index] = std::complex<float>(static_cast<float>(a[0]), static_cast<float>(b[0]));
dest[index + 1] = std::complex<float>(static_cast<float>(a[1]), static_cast<float>(b[1]));
}
}
void galileo_e5_b_code_gen_complex_sampled(own::span<std::complex<float>> dest,
uint32_t prn,
const std::array<char, 3>& signal_id,
int32_t sampling_freq,
uint32_t chip_shift)
{
constexpr uint32_t codeLength = GALILEO_E5B_CODE_LENGTH_CHIPS;
constexpr int32_t codeFreqBasis = GALILEO_E5B_CODE_CHIP_RATE_CPS;
const auto samplesPerCode = static_cast<uint32_t>(static_cast<double>(sampling_freq) / (static_cast<double>(codeFreqBasis) / static_cast<double>(codeLength)));
const uint32_t delay = ((codeLength - chip_shift) % codeLength) * samplesPerCode / codeLength;
std::vector<std::complex<float>> code_aux(codeLength);
galileo_e5_b_code_gen_complex_primary(code_aux, prn, signal_id);
if (sampling_freq != codeFreqBasis)
{
std::vector<std::complex<float>> resampled_signal_aux(samplesPerCode);
resampler(code_aux, resampled_signal_aux, codeFreqBasis, sampling_freq); // resamples code to sampling_freq
code_aux = std::move(resampled_signal_aux);
}
for (uint32_t i = 0; i < samplesPerCode; i++)
{
dest[(i + delay) % samplesPerCode] = code_aux[i];
}
}
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