mirror of https://github.com/gnss-sdr/gnss-sdr
69 lines
2.2 KiB
C++
69 lines
2.2 KiB
C++
/*!
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* \file tracking_2nd_DLL_filter.h
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* \brief Interface of a 2nd order DLL filter for code tracking loop.
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* \author Javier Arribas, 2011. jarribas(at)cttc.es
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*
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* Class that implements a 2nd order PLL filter for code tracking loop.
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* The algorithm is described in:
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* K.Borre, D.M.Akos, N.Bertelsen, P.Rinder, and S. H. Jensen,
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* A Software-Defined GPS and Galileo Receiver. A Single-Frequency Approach,
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* Birkhauser, 2007, Applied and Numerical Harmonic Analysis.
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*
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* -----------------------------------------------------------------------------
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*
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* GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
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* This file is part of GNSS-SDR.
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*
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* Copyright (C) 2010-2020 (see AUTHORS file for a list of contributors)
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* SPDX-License-Identifier: GPL-3.0-or-later
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*
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* -----------------------------------------------------------------------------
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*/
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#ifndef GNSS_SDR_TRACKING_2ND_DLL_FILTER_H
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#define GNSS_SDR_TRACKING_2ND_DLL_FILTER_H
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/** \addtogroup Tracking
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* \{ */
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/** \addtogroup Tracking_libs
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* \{ */
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/*!
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* \brief This class implements a 2nd order DLL filter for code tracking loop.
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*
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* The algorithm is described in:
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* K.Borre, D.M.Akos, N.Bertelsen, P.Rinder, and S. H. Jensen, A Software-Defined GPS
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* and Galileo Receiver. A Single-Frequency Approach,
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* Birkhauser, 2007, Applied and Numerical Harmonic Analysis.
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*/
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class Tracking_2nd_DLL_filter
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{
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public:
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Tracking_2nd_DLL_filter();
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~Tracking_2nd_DLL_filter() = default;
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explicit Tracking_2nd_DLL_filter(float pdi_code);
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void set_DLL_BW(float dll_bw_hz); //!< Set DLL filter bandwidth [Hz]
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void set_pdi(float pdi_code); //!< Set Summation interval for code [s]
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void initialize(); //!< Start tracking with acquisition information
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float get_code_nco(float DLL_discriminator); //!< Numerically controlled oscillator
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private:
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void calculate_lopp_coef(float* tau1, float* tau2, float lbw, float zeta, float k);
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// PLL filter parameters
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float d_tau1_code = 0.0;
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float d_tau2_code = 0.0;
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float d_pdi_code = 0.0;
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float d_dllnoisebandwidth = 0.0;
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float d_dlldampingratio = 0.0;
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float d_old_code_error = 0.0;
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float d_old_code_nco = 0.0;
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};
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/** \} */
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/** \} */
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#endif
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