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Modified Signal Processing Files

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piyush0411 2020-06-01 19:59:42 +05:30
parent 2dd7343ca3
commit 3f17a207fd
2 changed files with 122 additions and 2 deletions
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102
src/algorithms/libs/galileo_e5_signal_processing.cc
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@ -3,11 +3,13 @@
* \brief This library implements various functions for Galileo E5 signals such
* as replica code 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.
*
*
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2019 (see AUTHORS file for a list of contributors)
* Copyright (C) 2010-2020 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
@ -21,6 +23,7 @@
#include "galileo_e5_signal_processing.h"
#include "Galileo_E5a.h"
#include "Galileo_E5b.h"
#include "gnss_signal_processing.h"
#include <gnuradio/gr_complex.h>
#include <memory>
@ -123,3 +126,100 @@ void galileo_e5_a_code_gen_complex_sampled(own::span<std::complex<float>> _dest,
_dest[(i + delay) % _samplesPerCode] = _code[i];
}
}
void galileo_e5_b_code_gen_complex_primary(own::span<std::complex<float>> _dest,
int32_t _prn,
const std::array<char, 4>& _Signal) // to differentiate between E5a and E5b signal
{
uint32_t prn = _prn - 1;
uint32_t index = 0;
std::array<int32_t, 4> a{};
if ((_prn < 1) || (_prn > 50))
{
return;
}
if (_Signal[0] == '5' && _Signal[1] == 'b' && _Signal[2] == 'Q')
{
for (size_t i = 0; i < GALILEO_E5B_Q_PRIMARY_CODE[prn].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[prn].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[0] == '5' && _Signal[1] == 'b' && _Signal[2] == 'I')
{
for (size_t i = 0; i < GALILEO_E5B_I_PRIMARY_CODE[prn].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[prn].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[0] == '5' && _Signal[1] == 'b' && _Signal[2] == 'X')
{
std::array<int32_t, 4> b{};
for (size_t i = 0; i < GALILEO_E5B_I_PRIMARY_CODE[prn].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[prn].length() - 1]);
hex_to_binary_converter(b, GALILEO_E5B_Q_PRIMARY_CODE[prn][GALILEO_E5B_Q_PRIMARY_CODE[prn].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,
int32_t _fs,
uint32_t _chip_shift)
{
uint32_t _samplesPerCode;
uint32_t delay;
const uint32_t _codeLength = GALILEO_E5B_CODE_LENGTH_CHIPS;
const int32_t _codeFreqBasis = GALILEO_E5B_CODE_CHIP_RATE_CPS;
std::vector<std::complex<float>> _code(_codeLength);
galileo_e5_b_code_gen_complex_primary(_code, _prn, _Signal);
_samplesPerCode = static_cast<uint32_t>(static_cast<double>(_fs) / (static_cast<double>(_codeFreqBasis) / static_cast<double>(_codeLength)));
delay = ((_codeLength - _chip_shift) % _codeLength) * _samplesPerCode / _codeLength;
if (_fs != _codeFreqBasis)
{
std::vector<std::complex<float>> _resampled_signal(_samplesPerCode);
resampler(_code, _resampled_signal, _codeFreqBasis, _fs); // resamples code to fs
_code = std::move(_resampled_signal);
}
for (uint32_t i = 0; i < _samplesPerCode; i++)
{
_dest[(i + delay) % _samplesPerCode] = _code[i];
}
}

22
src/algorithms/libs/galileo_e5_signal_processing.h
View File

@ -3,11 +3,13 @@
* \brief This library implements various functions for Galileo E5 signals such
* as replica code 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.
*
*
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2019 (see AUTHORS file for a list of contributors)
* Copyright (C) 2010-2020 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
@ -52,4 +54,22 @@ void galileo_e5_a_code_gen_complex_sampled(own::span<std::complex<float>> _dest,
uint32_t _chip_shift);
/*!
* \brief Generates Galileo E5b code at 1 sample/chip
*/
void galileo_e5_b_code_gen_complex_primary(own::span<std::complex<float>> _dest,
int32_t _prn,
const std::array<char, 4>& _Signal);
/*!
* \brief Generates Galileo E5b complex code, shifted to the desired chip and
* sampled at a frequency fs
*/
void galileo_e5_b_code_gen_complex_sampled(own::span<std::complex<float>> _dest,
uint32_t _prn,
const std::array<char, 4>& _Signal,
int32_t _fs,
uint32_t _chip_shift);
#endif // GNSS_SDR_GALILEO_E5_SIGNAL_PROCESSING_H