gnss-sdr/src/core/system_parameters/GPS_L2C.h

/*!
 * \file GPS_L2C.h
 * \brief  Defines system parameters for GPS L2C signal
 * \author Javier Arribas, 2015. jarribas(at)cttc.es
 *
 * -------------------------------------------------------------------------
 *
 * Copyright (C) 2010-2019  (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.
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * -------------------------------------------------------------------------
 */


#ifndef GNSS_SDR_GPS_L2C_H
#define GNSS_SDR_GPS_L2C_H


#include "GPS_CNAV.h"
#include "MATH_CONSTANTS.h"
#include "gnss_frequencies.h"
#include <cstdint>
#include <utility>  // std::pair
#include <vector>


// Physical constants
constexpr double GPS_L2_C_M_S = 299792458.0;                //!< The speed of light, [m/s]
constexpr double GPS_L2_C_M_MS = 299792.4580;               //!< The speed of light, [m/ms]
constexpr double GPS_L2_PI = 3.1415926535898;               //!< Pi as defined in IS-GPS-200K
constexpr double GPS_L2_TWO_PI = 6.283185307179586;         //!< 2Pi as defined in IS-GPS-200K
constexpr double GPS_L2_OMEGA_EARTH_DOT = 7.2921151467e-5;  //!< Earth rotation rate, [rad/s]
constexpr double GPS_L2_GM = 3.986005e14;                   //!< Universal gravitational constant times the mass of the Earth, [m^3/s^2]
constexpr double GPS_L2_F = -4.442807633e-10;               //!< Constant, [s/(m)^(1/2)]

// carrier and code frequencies
constexpr double GPS_L2_FREQ_HZ = FREQ2;  //!< L2 [Hz]

constexpr double GPS_L2_M_CODE_RATE_CPS = 0.5115e6;    //!< GPS L2 M code rate [chips/s]
constexpr int32_t GPS_L2_M_CODE_LENGTH_CHIPS = 10230;  //!< GPS L2 M code length [chips]
constexpr double GPS_L2_M_PERIOD_S = 0.02;             //!< GPS L2 M code period [seconds]

constexpr double GPS_L2_L_CODE_RATE_CPS = 0.5115e6;     //!< GPS L2 L code rate [chips/s]
constexpr int32_t GPS_L2_L_CODE_LENGTH_CHIPS = 767250;  //!< GPS L2 L code length [chips]
constexpr double GPS_L2_L_PERIOD_S = 1.5;               //!< GPS L2 L code period [seconds]

constexpr int32_t GPS_L2C_HISTORY_DEEP = 5;

// optimum parameters
constexpr uint32_t GPS_L2C_OPT_ACQ_FS_SPS = 2000000;  //!< Sampling frequency that maximizes the acquisition SNR while using a non-multiple of chip rate


constexpr int32_t GPS_L2C_M_INIT_REG[115] =
    {0742417664, 0756014035, 0002747144, 0066265724,     // 1:4
        0601403471, 0703232733, 0124510070, 0617316361,  // 5:8
        0047541621, 0733031046, 0713512145, 0024437606,
        0021264003, 0230655351, 0001314400, 0222021506,
        0540264026, 0205521705, 0064022144, 0120161274,
        0044023533, 0724744327, 0045743577, 0741201660,
        0700274134, 0010247261, 0713433445, 0737324162,
        0311627434, 0710452007, 0722462133, 0050172213,
        0500653703, 0755077436, 0136717361, 0756675453,
        0435506112, 0771353753, 0226107701, 0022025110,
        0402466344, 0752566114, 0702011164, 0041216771,
        0047457275, 0266333164, 0713167356, 0060546335,
        0355173035, 0617201036, 0157465571, 0767360553,
        0023127030, 0431343777, 0747317317, 0045706125,
        0002744276, 0060036467, 0217744147, 0603340174,  // 57:60
        0326616775, 0063240065, 0111460621,              // 61:63
        0604055104, 0157065232, 0013305707, 0603552017,  // 159:162
        0230461355, 0603653437, 0652346475, 0743107103,
        0401521277, 0167335110, 0014013575, 0362051132,
        0617753265, 0216363634, 0755561123, 0365304033,
        0625025543, 0054420334, 0415473671, 0662364360,
        0373446602, 0417564100, 0000526452, 0226631300,
        0113752074, 0706134401, 0041352546, 0664630154,
        0276524255, 0714720530, 0714051771, 0044526647,
        0207164322, 0262120161, 0204244652, 0202133131,
        0714351204, 0657127260, 0130567507, 0670517677,
        0607275514, 0045413633, 0212645405, 0613700455,
        0706202440, 0705056276, 0020373522, 0746013617,
        0132720621, 0434015513, 0566721727, 0140633660};

constexpr int32_t GPS_L2_CNAV_DATA_PAGE_BITS = 300;  //!< GPS L2 CNAV page length, including preamble and CRC [bits]
constexpr int32_t GPS_L2_SYMBOLS_PER_BIT = 2;
constexpr int32_t GPS_L2_SAMPLES_PER_SYMBOL = 1;
constexpr int32_t GPS_L2_CNAV_DATA_PAGE_SYMBOLS = 600;
constexpr int32_t GPS_L2_CNAV_DATA_PAGE_DURATION_S = 12;

#endif  // GNSS_SDR_GPS_L2C_H