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gnss-sdr/src/algorithms/libs/beidou_b3i_signal_processing.cc

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bds b3i: Adding code to process BeiDou B3I signals Adds code to perform acq and trk in BeiDou B3I signals. Stages of telemetry decoding, observables computation and pvt use existing code on the platform. Some further testing is required
2019-01-25 21:43:00 +00:00
/*!
* \file beidou_b3i_signal_processing.cc
* \brief This class implements various functions for BeiDou B1I signal
* \author Damian Miralles, 2019. dmiralles2009@gmail.com
*
* Detailed description of the file here if needed.
*
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2015 (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 <http://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#include "beidou_b3i_signal_processing.h"
auto auxCeil = [](float x) { return static_cast<int>(static_cast<long>((x) + 1)); };
Introduce gsl::span. Bound checking at compile time, no overhead at runtime See https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md
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void beidou_b3i_code_gen_int(gsl::span<int> _dest, signed int _prn, unsigned int _chip_shift)
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{
const unsigned int _code_length = 10230;
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bool G1[_code_length];
bool G2[_code_length];
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std::array<bool, 13> G1_register = {{true, true, true, true, true, true, true, true, true, true, true, true, true}};
std::array<bool, 13> G2_register = {{true, true, true, true, true, true, true, true, true, true, true, true, true}};
std::array<bool, 13> G1_register_reset = {{false, false, true, true, true, true, true, true, true, true, true, true, true}};
bds_b3i: bug fix in code generation Moved code generation logic to use bool type to keep same notation as the previous implementations. More testing in code is required
2019-01-28 01:05:41 +00:00
bool feedback1, feedback2, aux;
uint32_t lcv, lcv2, delay;
bds b3i: Adding code to process BeiDou B3I signals Adds code to perform acq and trk in BeiDou B3I signals. Stages of telemetry decoding, observables computation and pvt use existing code on the platform. Some further testing is required
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int32_t prn_idx = _prn - 1;
Remove clang-format label
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std::array<std::array<bool, 13>, 63> G2_register_shifted =
{{{{true, false, true, false, true, true, true, true, true, true, true, true, true}},
{{true, true, true, true, false, false, false, true, false, true, false, true, true}},
{{true, false, true, true, true, true, false, false, false, true, false, true, false}},
{{true, true, true, true, true, true, true, true, true, true, false, true, true}},
{{true, true, false, false, true, false, false, false, true, true, true, true, true}},
{{true, false, false, true, false, false, true, true, false, false, true, false, false}},
{{true, true, true, true, true, true, true, false, true, false, false, true, false}},
{{true, true, true, false, true, true, true, true, true, true, true, false, true}},
{{true, false, true, false, false, false, false, false, false, false, false, true, false}},
{{false, false, true, false, false, false, false, false, true, true, false, true, true}},
{{true, true, true, false, true, false, true, true, true, false, false, false, false}},
{{false, false, true, false, true, true, false, false, true, true, true, true, false}},
{{false, true, true, false, false, true, false, false, true, false, true, false, true}},
{{false, true, true, true, false, false, false, true, false, false, true, true, false}},
{{true, false, false, false, true, true, false, false, false, true, false, false, true}},
{{true, true, true, false, false, false, true, true, true, true, true, false, false}},
{{false, false, true, false, false, true, true, false, false, false, true, false, true}},
{{false, false, false, false, false, true, true, true, false, true, true, false, false}},
{{true, false, false, false, true, false, true, false, true, false, true, true, true}},
{{false, false, false, true, false, true, true, false, true, true, true, true, false}},
{{false, false, true, false, false, false, false, true, false, true, true, false, true}},
{{false, false, true, false, true, true, false, false, false, true, false, true, false}},
{{false, false, false, true, false, true, true, false, false, true, true, true, true}},
{{false, false, true, true, false, false, true, true, false, false, false, true, false}},
{{false, false, true, true, true, false, true, false, false, true, false, false, false}},
{{false, true, false, false, true, false, false, true, false, true, false, false, true}},
{{true, false, true, true, false, true, true, false, true, false, false, true, true}},
{{true, false, true, false, true, true, true, true, false, false, false, true, false}},
{{false, false, false, true, false, true, true, true, true, false, true, false, true}},
{{false, true, true, true, true, true, true, true, true, true, true, true, true}},
{{false, true, true, false, true, true, false, false, false, true, true, true, true}},
{{true, false, true, false, true, true, false, false, false, true, false, false, true}},
{{true, false, false, true, false, true, false, true, false, true, false, true, true}},
{{true, true, false, false, true, true, false, true, false, false, true, false, true}},
{{true, true, false, true, false, false, true, false, true, true, true, false, true}},
{{true, true, true, true, true, false, true, true, true, false, true, false, false}},
{{false, false, true, false, true, false, true, true, false, false, true, true, true}},
{{true, true, true, false, true, false, false, false, true, false, false, false, false}},
{{true, true, false, true, true, true, false, false, true, false, false, false, false}},
{{true, true, false, true, false, true, true, false, false, true, true, true, false}},
{{true, false, false, false, false, false, false, true, true, false, true, false, false}},
{{false, true, false, true, true, true, true, false, true, true, false, false, true}},
{{false, true, true, false, true, true, false, true, true, true, true, false, false}},
{{true, true, false, true, false, false, true, true, true, false, false, false, true}},
{{false, false, true, true, true, false, false, true, false, false, false, true, false}},
{{false, true, false, true, false, true, true, false, false, false, true, false, true}},
{{true, false, false, true, true, true, true, true, false, false, true, true, false}},
{{true, true, true, true, true, false, true, false, false, true, false, false, false}},
{{false, false, false, false, true, false, true, false, false, true, false, false, true}},
{{true, false, false, false, false, true, false, true, false, true, true, false, false}},
{{true, true, true, true, false, false, true, false, false, true, true, false, false}},
{{false, true, false, false, true, true, false, false, false, true, true, true, true}},
{{false, false, false, false, false, false, false, false, true, true, false, false, false}},
{{true, false, false, false, false, false, false, false, false, false, true, false, false}},
{{false, false, true, true, false, true, false, true, false, false, true, true, false}},
{{true, false, true, true, false, false, true, false, false, false, true, true, false}},
{{false, true, true, true, false, false, true, true, true, true, false, false, false}},
{{false, false, true, false, true, true, true, false, false, true, false, true, false}},
{{true, true, false, false, true, true, true, true, true, false, true, true, false}},
{{true, false, false, true, false, false, true, false, false, false, true, false, true}},
{{false, true, true, true, false, false, false, true, false, false, false, false, false}},
{{false, false, true, true, false, false, true, false, false, false, false, true, false}},
{{false, false, true, false, false, false, true, false, false, true, true, true, false}}}};
bds_b3i: bug fix in code generation Moved code generation logic to use bool type to keep same notation as the previous implementations. More testing in code is required
2019-01-28 01:05:41 +00:00
// A simple error check
if ((prn_idx < 0) || (prn_idx > 63))
bds b3i: Adding code to process BeiDou B3I signals Adds code to perform acq and trk in BeiDou B3I signals. Stages of telemetry decoding, observables computation and pvt use existing code on the platform. Some further testing is required
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return;
bds_b3i: bug fix in code generation Moved code generation logic to use bool type to keep same notation as the previous implementations. More testing in code is required
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// Assign shifted G2 register based on prn number
bds b3i: Adding code to process BeiDou B3I signals Adds code to perform acq and trk in BeiDou B3I signals. Stages of telemetry decoding, observables computation and pvt use existing code on the platform. Some further testing is required
2019-01-25 21:43:00 +00:00
G2_register = G2_register_shifted[prn_idx];
Fix building, apply formatting
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std::reverse(G2_register.begin(), G2_register.end());
bds b3i: Adding code to process BeiDou B3I signals Adds code to perform acq and trk in BeiDou B3I signals. Stages of telemetry decoding, observables computation and pvt use existing code on the platform. Some further testing is required
2019-01-25 21:43:00 +00:00
bds_b3i: bug fix in code generation Moved code generation logic to use bool type to keep same notation as the previous implementations. More testing in code is required
2019-01-28 01:05:41 +00:00
// Generate G1 and G2 Register
bds b3i: Adding code to process BeiDou B3I signals Adds code to perform acq and trk in BeiDou B3I signals. Stages of telemetry decoding, observables computation and pvt use existing code on the platform. Some further testing is required
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for (lcv = 0; lcv < _code_length; lcv++)
Fix building, apply formatting
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{
G1[lcv] = G1_register[0];
G2[lcv] = G2_register[0];
//feedback1 = (test_G1_register[0]+test_G1_register[2]+test_G1_register[3]+test_G1_register[12]) & 0x1;
feedback1 = (G1_register[0] + G1_register[9] + G1_register[10] + G1_register[12]) & 0x01;
feedback2 = (G2_register[0] + G2_register[1] + G2_register[3] + G2_register[4] +
G2_register[6] + G2_register[7] + G2_register[8] + G2_register[12]) &
0x01;
for (lcv2 = 0; lcv2 < 12; lcv2++)
{
G1_register[lcv2] = G1_register[lcv2 + 1];
G2_register[lcv2] = G2_register[lcv2 + 1];
}
G1_register[12] = feedback1;
G2_register[12] = feedback2;
// Reset G1 register if sequence found
if (G1_register == G1_register_reset)
{
Apply clang-tidy fixes
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G1_register = {{true, true, true, true, true, true, true, true, true, true, true, true, true}};
Fix building, apply formatting
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}
}
bds_b3i: bug fix in code generation Moved code generation logic to use bool type to keep same notation as the previous implementations. More testing in code is required
2019-01-28 01:05:41 +00:00
delay = _code_length;
delay += _chip_shift;
delay %= _code_length;
/* Generate PRN from G1 and G2 Registers */
for (lcv = 0; lcv < _code_length; lcv++)
{
aux = (G1[(lcv + _chip_shift) % _code_length] + G2[delay]) & 0x01;
if (aux == true)
{
_dest[lcv] = 1;
}
else
{
_dest[lcv] = -1;
}
delay++;
delay %= _code_length;
}
bds b3i: Adding code to process BeiDou B3I signals Adds code to perform acq and trk in BeiDou B3I signals. Stages of telemetry decoding, observables computation and pvt use existing code on the platform. Some further testing is required
2019-01-25 21:43:00 +00:00
}
Introduce gsl::span. Bound checking at compile time, no overhead at runtime See https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md
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void beidou_b3i_code_gen_float(gsl::span<float> _dest, signed int _prn, unsigned int _chip_shift)
bds b3i: Adding code to process BeiDou B3I signals Adds code to perform acq and trk in BeiDou B3I signals. Stages of telemetry decoding, observables computation and pvt use existing code on the platform. Some further testing is required
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{
unsigned int _code_length = 10230;
int b3i_code_int[10230];
beidou_b3i_code_gen_int(b3i_code_int, _prn, _chip_shift);
for (unsigned int ii = 0; ii < _code_length; ++ii)
{
_dest[ii] = static_cast<float>(b3i_code_int[ii]);
}
}
Introduce gsl::span. Bound checking at compile time, no overhead at runtime See https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md
2019-06-28 23:28:30 +00:00
void beidou_b3i_code_gen_complex(gsl::span<std::complex<float>> _dest, signed int _prn, unsigned int _chip_shift)
bds b3i: Adding code to process BeiDou B3I signals Adds code to perform acq and trk in BeiDou B3I signals. Stages of telemetry decoding, observables computation and pvt use existing code on the platform. Some further testing is required
2019-01-25 21:43:00 +00:00
{
unsigned int _code_length = 10230;
int b3i_code_int[10230];
beidou_b3i_code_gen_int(b3i_code_int, _prn, _chip_shift);
for (unsigned int ii = 0; ii < _code_length; ++ii)
{
_dest[ii] = std::complex<float>(static_cast<float>(b3i_code_int[ii]), 0.0f);
}
}
Introduce gsl::span. Bound checking at compile time, no overhead at runtime See https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md
2019-06-28 23:28:30 +00:00
void beidou_b3i_code_gen_complex_sampled(gsl::span<std::complex<float>> _dest, unsigned int _prn, int _fs, unsigned int _chip_shift)
bds b3i: Adding code to process BeiDou B3I signals Adds code to perform acq and trk in BeiDou B3I signals. Stages of telemetry decoding, observables computation and pvt use existing code on the platform. Some further testing is required
2019-01-25 21:43:00 +00:00
{
// This function is based on the GNU software GPS for MATLAB in the Kay Borre book
std::complex<float> _code[10230];
signed int _samplesPerCode, _codeValueIndex;
float _ts;
float _tc;
float aux;
const signed int _codeFreqBasis = 10230000; //Hz
const signed int _codeLength = 10230;
//--- Find number of samples per spreading code ----------------------------
_samplesPerCode = static_cast<signed int>(static_cast<double>(_fs) / static_cast<double>(_codeFreqBasis / _codeLength));
//--- Find time constants --------------------------------------------------
Fix building, apply formatting
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_ts = 1.0 / static_cast<float>(_fs); // Sampling period in sec
_tc = 1.0 / static_cast<float>(_codeFreqBasis); // C/A chip period in sec
bds b3i: Adding code to process BeiDou B3I signals Adds code to perform acq and trk in BeiDou B3I signals. Stages of telemetry decoding, observables computation and pvt use existing code on the platform. Some further testing is required
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beidou_b3i_code_gen_complex(_code, _prn, _chip_shift); //generate C/A code 1 sample per chip
for (signed int i = 0; i < _samplesPerCode; i++)
{
//=== Digitizing =======================================================
//--- Make index array to read C/A code values -------------------------
// The length of the index array depends on the sampling frequency -
// number of samples per millisecond (because one C/A code period is one
// millisecond).
// _codeValueIndex = ceil((_ts * ((float)i + 1)) / _tc) - 1;
aux = (_ts * (i + 1)) / _tc;
_codeValueIndex = auxCeil(aux) - 1;
//--- Make the digitized version of the C/A code -----------------------
// The "upsampled" code is made by selecting values form the CA code
// chip array (caCode) for the time instances of each sample.
if (i == _samplesPerCode - 1)
{
//--- Correct the last index (due to number rounding issues) -----------
_dest[i] = _code[_codeLength - 1];
}
else
{
_dest[i] = _code[_codeValueIndex]; //repeat the chip -> upsample
}
}
}
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