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gnss-sdr/src/algorithms/tracking/libs/tracking_discriminators.h
2019-09-13 08:56:37 +02:00

119 lines
4.3 KiB
C

/*!
* \file tracking_discriminators.h
* \brief Interface of a library with a set of code tracking and carrier
* tracking discriminators.
* \authors <ul>
* <li> Javier Arribas, 2011. jarribas(at)cttc.es
* <li> Luis Esteve, 2012. luis(at)epsilon-formacion.com
* </ul>
*
* Library with a set of code tracking and carrier tracking discriminators
* that is used by the tracking algorithms.
*
* -------------------------------------------------------------------------
*
* 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.
*
* 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 <https://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#ifndef GNSS_SDR_TRACKING_DISCRIMINATORS_H_
#define GNSS_SDR_TRACKING_DISCRIMINATORS_H_
#include <gnuradio/gr_complex.h>
/*! brief FLL four quadrant arctan discriminator
*
* FLL four quadrant arctan discriminator:
* \f{equation}
* \frac{\phi_2-\phi_1}{t_2-t1}=\frac{ATAN2(cross,dot)}{t_1-t_2},
* \f}
* where \f$cross=I_{PS1}Q_{PS2}-I_{PS2}Q_{PS1}\f$ and \f$dot=I_{PS1}I_{PS2}+Q_{PS1}Q_{PS2}\f$,
* \f$I_{PS1},Q_{PS1}\f$ are the inphase and quadrature prompt correlator outputs respectively at sample time \f$t_1\f$, and
* \f$I_{PS2},Q_{PS2}\f$ are the inphase and quadrature prompt correlator outputs respectively at sample time \f$t_2\f$. The output is in [radians/second].
*/
double fll_four_quadrant_atan(gr_complex prompt_s1, gr_complex prompt_s2, double t1, double t2);
/*
* FLL differential arctan discriminator:
* \f{equation}
* e_{atan}(k)=\frac{1}{t_1-t_2}\text{phase_unwrap}(\tan^-1(\frac{Q(k)}{I(k)})-\tan^-1(\frac{Q(k-1)}{I(k-1)}))
* \f}
* The output is in [radians/second].
*/
double fll_diff_atan(gr_complex prompt_s1, gr_complex prompt_s2, double t1, double t2);
/*! \brief Phase unwrapping function, input is [rad]
*/
double phase_unwrap(double phase_rad);
/*! \brief PLL four quadrant arctan discriminator
*
* PLL four quadrant arctan discriminator:
* \f{equation}
* \phi=ATAN2(Q_{PS},I_{PS}),
* \f}
* where \f$I_{PS1},Q_{PS1}\f$ are the inphase and quadrature prompt correlator outputs respectively. The output is in [radians].
*/
double pll_four_quadrant_atan(gr_complex prompt_s1);
/*! \brief PLL Costas loop two quadrant arctan discriminator
*
* PLL Costas loop two quadrant arctan discriminator:
* \f{equation}
* \phi=ATAN\left(\frac{Q_{PS}}{I_{PS}}\right),
* \f}
* where \f$I_{PS1},Q_{PS1}\f$ are the inphase and quadrature prompt correlator outputs respectively. The output is in [radians].
*/
double pll_cloop_two_quadrant_atan(gr_complex prompt_s1);
/*! \brief DLL Noncoherent Early minus Late envelope normalized discriminator
*
* DLL Noncoherent Early minus Late envelope normalized discriminator:
* \f{equation}
* error=\frac{E-L}{E+L},
* \f}
* where \f$E=\sqrt{I_{ES}^2+Q_{ES}^2}\f$ is the Early correlator output absolute value and
* \f$L=\sqrt{I_{LS}^2+Q_{LS}^2}\f$ is the Late correlator output absolute value. The output is in [chips].
*/
double dll_nc_e_minus_l_normalized(gr_complex early_s1, gr_complex late_s1);
/*! \brief DLL Noncoherent Very Early Minus Late Power (VEMLP) normalized discriminator
*
* DLL Noncoherent Very Early Minus Late Power (VEMLP) normalized discriminator, using the outputs
* of four correlators, Very Early (VE), Early (E), Late (L) and Very Late (VL):
* \f{equation}
* error=\frac{E-L}{E+L},
* \f}
* where \f$E=\sqrt{I_{VE}^2+Q_{VE}^2+I_{E}^2+Q_{E}^2}\f$ and
* \f$L=\sqrt{I_{VL}^2+Q_{VL}^2+I_{L}^2+Q_{L}^2}\f$ . The output is in [chips].
*/
double dll_nc_vemlp_normalized(gr_complex very_early_s1, gr_complex early_s1, gr_complex late_s1, gr_complex very_late_s1);
#endif