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https://github.com/gnss-sdr/gnss-sdr
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271 lines
11 KiB
C++
271 lines
11 KiB
C++
/*!
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* \file galileo_e1_signal_processing.cc
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* \brief This library implements various functions for Galileo E1 signals
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* \author Luis Esteve, 2012. luis(at)epsilon-formacion.com
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*
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* Detailed description of the file here if needed.
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*
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* -------------------------------------------------------------------------
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*
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* Copyright (C) 2010-2019 (see AUTHORS file for a list of contributors)
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*
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* GNSS-SDR is a software defined Global Navigation
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* Satellite Systems receiver
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*
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* This file is part of GNSS-SDR.
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*
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* GNSS-SDR is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GNSS-SDR is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNSS-SDR. If not, see <https://www.gnu.org/licenses/>.
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*
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* -------------------------------------------------------------------------
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*/
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#include "galileo_e1_signal_processing.h"
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#include "Galileo_E1.h"
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#include "gnss_signal_processing.h"
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#include <memory>
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#include <string>
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#include <utility>
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#include <vector>
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void galileo_e1_code_gen_int(gsl::span<int> _dest, const std::array<char, 3>& _Signal, int32_t _prn)
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{
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std::string _galileo_signal = _Signal.data();
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int32_t prn = _prn - 1;
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int32_t index = 0;
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// A simple error check
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if ((_prn < 1) || (_prn > 50))
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{
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return;
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}
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if (_galileo_signal.rfind("1B") != std::string::npos && _galileo_signal.length() >= 2)
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{
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for (char i : GALILEO_E1_B_PRIMARY_CODE[prn])
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{
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hex_to_binary_converter(_dest.subspan(index, 4), i);
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index += 4;
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}
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}
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else if (_galileo_signal.rfind("1C") != std::string::npos && _galileo_signal.length() >= 2)
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{
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for (char i : GALILEO_E1_C_PRIMARY_CODE[prn])
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{
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hex_to_binary_converter(_dest.subspan(index, 4), i);
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index += 4;
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}
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}
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}
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void galileo_e1_sinboc_11_gen_int(gsl::span<int> _dest, gsl::span<const int> _prn)
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{
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const uint32_t _length_in = GALILEO_E1_B_CODE_LENGTH_CHIPS;
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auto _period = static_cast<uint32_t>(_dest.size() / _length_in);
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for (uint32_t i = 0; i < _length_in; i++)
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{
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for (uint32_t j = 0; j < (_period / 2); j++)
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{
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_dest[i * _period + j] = _prn[i];
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}
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for (uint32_t j = (_period / 2); j < _period; j++)
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{
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_dest[i * _period + j] = -_prn[i];
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}
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}
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}
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void galileo_e1_sinboc_61_gen_int(gsl::span<int> _dest, gsl::span<const int> _prn)
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{
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const uint32_t _length_in = GALILEO_E1_B_CODE_LENGTH_CHIPS;
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auto _period = static_cast<uint32_t>(_dest.size() / _length_in);
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for (uint32_t i = 0; i < _length_in; i++)
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{
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for (uint32_t j = 0; j < _period; j += 2)
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{
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_dest[i * _period + j] = _prn[i];
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}
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for (uint32_t j = 1; j < _period; j += 2)
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{
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_dest[i * _period + j] = -_prn[i];
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}
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}
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}
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void galileo_e1_code_gen_sinboc11_float(gsl::span<float> _dest, const std::array<char, 3>& _Signal, uint32_t _prn)
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{
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std::string _galileo_signal = _Signal.data();
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const auto _codeLength = static_cast<uint32_t>(GALILEO_E1_B_CODE_LENGTH_CHIPS);
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std::array<int32_t, 4092> primary_code_E1_chips{};
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galileo_e1_code_gen_int(primary_code_E1_chips, _Signal, _prn); // generate Galileo E1 code, 1 sample per chip
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for (uint32_t i = 0; i < _codeLength; i++)
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{
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_dest[2 * i] = static_cast<float>(primary_code_E1_chips[i]);
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_dest[2 * i + 1] = -_dest[2 * i];
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}
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}
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void galileo_e1_gen_float(gsl::span<float> _dest, gsl::span<int> _prn, const std::array<char, 3>& _Signal)
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{
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std::string _galileo_signal = _Signal.data();
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const uint32_t _codeLength = 12 * GALILEO_E1_B_CODE_LENGTH_CHIPS;
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const float alpha = sqrt(10.0 / 11.0);
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const float beta = sqrt(1.0 / 11.0);
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std::array<int32_t, 12 * 4092> sinboc_11{};
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std::array<int32_t, 12 * 4092> sinboc_61{};
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gsl::span<int32_t> sinboc_11_(sinboc_11.data(), _codeLength);
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gsl::span<int32_t> sinboc_61_(sinboc_61.data(), _codeLength);
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galileo_e1_sinboc_11_gen_int(sinboc_11_, _prn); // generate sinboc(1,1) 12 samples per chip
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galileo_e1_sinboc_61_gen_int(sinboc_61_, _prn); // generate sinboc(6,1) 12 samples per chip
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if (_galileo_signal.rfind("1B") != std::string::npos && _galileo_signal.length() >= 2)
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{
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for (uint32_t i = 0; i < _codeLength; i++)
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{
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_dest[i] = alpha * static_cast<float>(sinboc_11[i]) +
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beta * static_cast<float>(sinboc_61[i]);
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}
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}
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else if (_galileo_signal.rfind("1C") != std::string::npos && _galileo_signal.length() >= 2)
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{
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for (uint32_t i = 0; i < _codeLength; i++)
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{
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_dest[i] = alpha * static_cast<float>(sinboc_11[i]) -
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beta * static_cast<float>(sinboc_61[i]);
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}
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}
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}
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void galileo_e1_code_gen_float_sampled(gsl::span<float> _dest, const std::array<char, 3>& _Signal,
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bool _cboc, uint32_t _prn, int32_t _fs, uint32_t _chip_shift,
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bool _secondary_flag)
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{
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// This function is based on the GNU software GPS for MATLAB in Kay Borre's book
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std::string _galileo_signal = _Signal.data();
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uint32_t _samplesPerCode;
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const int32_t _codeFreqBasis = GALILEO_E1_CODE_CHIP_RATE_CPS; // Hz
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std::vector<int32_t> primary_code_E1_chips(static_cast<int32_t>(GALILEO_E1_B_CODE_LENGTH_CHIPS));
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_samplesPerCode = static_cast<uint32_t>(static_cast<double>(_fs) / (static_cast<double>(_codeFreqBasis) / GALILEO_E1_B_CODE_LENGTH_CHIPS));
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const int32_t _samplesPerChip = (_cboc == true) ? 12 : 2;
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const uint32_t delay = ((static_cast<int32_t>(GALILEO_E1_B_CODE_LENGTH_CHIPS) - _chip_shift) % static_cast<int32_t>(GALILEO_E1_B_CODE_LENGTH_CHIPS)) * _samplesPerCode / GALILEO_E1_B_CODE_LENGTH_CHIPS;
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galileo_e1_code_gen_int(primary_code_E1_chips, _Signal, _prn); // generate Galileo E1 code, 1 sample per chip
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const uint32_t _codeLength = _samplesPerChip * GALILEO_E1_B_CODE_LENGTH_CHIPS;
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std::unique_ptr<float> _signal_E1{new float[_codeLength]};
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gsl::span<float> _signal_E1_span(_signal_E1, _codeLength);
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if (_cboc == true)
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{
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galileo_e1_gen_float(_signal_E1_span, primary_code_E1_chips, _Signal); // generate cboc 12 samples per chip
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}
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else
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{
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std::vector<int32_t> _signal_E1_int(static_cast<int32_t>(_codeLength));
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galileo_e1_sinboc_11_gen_int(_signal_E1_int, primary_code_E1_chips); // generate sinboc(1,1) 2 samples per chip
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for (uint32_t ii = 0; ii < _codeLength; ++ii)
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{
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_signal_E1_span[ii] = static_cast<float>(_signal_E1_int[ii]);
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}
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}
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if (_fs != _samplesPerChip * _codeFreqBasis)
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{
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std::unique_ptr<float> _resampled_signal{new float[_samplesPerCode]};
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resampler(gsl::span<float>(_signal_E1, _codeLength), gsl::span<float>(_resampled_signal, _samplesPerCode), _samplesPerChip * _codeFreqBasis, _fs); // resamples code to fs
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_signal_E1 = std::move(_resampled_signal);
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}
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uint32_t size_signal_E1 = _codeLength;
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if (_fs != _samplesPerChip * _codeFreqBasis)
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{
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size_signal_E1 = _samplesPerCode;
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}
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gsl::span<float> _signal_E1_span_aux(_signal_E1, size_signal_E1);
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if (_galileo_signal.rfind("1C") != std::string::npos && _galileo_signal.length() >= 2 && _secondary_flag)
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{
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std::unique_ptr<float> _signal_E1C_secondary{new float[static_cast<int32_t>(GALILEO_E1_C_SECONDARY_CODE_LENGTH) * _samplesPerCode]};
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gsl::span<float> _signal_E1C_secondary_span(_signal_E1C_secondary, static_cast<int32_t>(GALILEO_E1_C_SECONDARY_CODE_LENGTH) * _samplesPerCode);
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for (uint32_t i = 0; i < static_cast<uint32_t>(GALILEO_E1_C_SECONDARY_CODE_LENGTH); i++)
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{
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for (unsigned k = 0; k < _samplesPerCode; k++)
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{
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_signal_E1C_secondary_span[i * _samplesPerCode + k] = _signal_E1_span_aux[k] * (GALILEO_E1_C_SECONDARY_CODE[i] == '0' ? 1.0F : -1.0F);
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}
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}
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_samplesPerCode *= static_cast<int32_t>(GALILEO_E1_C_SECONDARY_CODE_LENGTH);
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_signal_E1 = std::move(_signal_E1C_secondary);
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}
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if (_galileo_signal.rfind("1C") != std::string::npos && _galileo_signal.length() >= 2 && _secondary_flag)
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{
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size_signal_E1 = static_cast<int32_t>(GALILEO_E1_C_SECONDARY_CODE_LENGTH) * _samplesPerCode;
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}
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gsl::span<float> _signal_E1_span_aux2(_signal_E1, size_signal_E1);
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for (uint32_t i = 0; i < _samplesPerCode; i++)
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{
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_dest[(i + delay) % _samplesPerCode] = _signal_E1_span_aux2[i];
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}
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}
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void galileo_e1_code_gen_complex_sampled(gsl::span<std::complex<float>> _dest, const std::array<char, 3>& _Signal,
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bool _cboc, uint32_t _prn, int32_t _fs, uint32_t _chip_shift,
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bool _secondary_flag)
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{
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std::string _galileo_signal = _Signal.data();
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const int32_t _codeFreqBasis = GALILEO_E1_CODE_CHIP_RATE_CPS; // Hz
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auto _samplesPerCode = static_cast<uint32_t>(static_cast<double>(_fs) /
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(static_cast<double>(_codeFreqBasis) / GALILEO_E1_B_CODE_LENGTH_CHIPS));
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if (_galileo_signal.rfind("1C") != std::string::npos && _galileo_signal.length() >= 2 && _secondary_flag)
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{
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_samplesPerCode *= static_cast<int32_t>(GALILEO_E1_C_SECONDARY_CODE_LENGTH);
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}
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std::vector<float> real_code(_samplesPerCode);
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galileo_e1_code_gen_float_sampled(real_code, _Signal, _cboc, _prn, _fs, _chip_shift, _secondary_flag);
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for (uint32_t ii = 0; ii < _samplesPerCode; ++ii)
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{
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_dest[ii] = std::complex<float>(real_code[ii], 0.0F);
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}
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}
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void galileo_e1_code_gen_float_sampled(gsl::span<float> _dest, const std::array<char, 3>& _Signal,
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bool _cboc, uint32_t _prn, int32_t _fs, uint32_t _chip_shift)
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{
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galileo_e1_code_gen_float_sampled(_dest, _Signal, _cboc, _prn, _fs, _chip_shift, false);
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}
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void galileo_e1_code_gen_complex_sampled(gsl::span<std::complex<float>> _dest, const std::array<char, 3>& _Signal,
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bool _cboc, uint32_t _prn, int32_t _fs, uint32_t _chip_shift)
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{
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galileo_e1_code_gen_complex_sampled(_dest, _Signal, _cboc, _prn, _fs, _chip_shift, false);
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}
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