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diff --git a/gr-digital/include/digital/mpsk_snr_est.h b/gr-digital/include/digital/mpsk_snr_est.h deleted file mode 100644 index 30c20e755e..0000000000 --- a/gr-digital/include/digital/mpsk_snr_est.h +++ /dev/null @@ -1,288 +0,0 @@ -/* -*- c++ -*- */ -/* - * Copyright 2011,2012 Free Software Foundation, Inc. - * - * This file is part of GNU Radio - * - * GNU Radio 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, or (at your option) - * any later version. - * - * GNU Radio 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 GNU Radio; see the file COPYING. If not, write to - * the Free Software Foundation, Inc., 51 Franklin Street, - * Boston, MA 02110-1301, USA. - */ - -#ifndef INCLUDED_DIGITAL_MPSK_SNR_EST_H -#define INCLUDED_DIGITAL_MPSK_SNR_EST_H - -#include <digital/api.h> -#include <gnuradio/gr_complex.h> - -namespace gr { - namespace digital { - - /*! - * \brief A block for computing SNR of a signal. - * \ingroup measurement_tools_blk - * - * \details - * Below are some ROUGH estimates of what values of SNR each of - * these types of estimators is good for. In general, these offer - * a trade-off between accuracy and performance. - * - * \li SNR_EST_SIMPLE: Simple estimator (>= 7 dB) - * \li SNR_EST_SKEW: Skewness-base est (>= 5 dB) - * \li SNR_EST_M2M4: 2nd & 4th moment est (>= 1 dB) - * \li SNR_EST_SVR: SVR-based est (>= 0dB) - */ - typedef enum { - SNR_EST_SIMPLE = 0, // Simple estimator (>= 7 dB) - SNR_EST_SKEW, // Skewness-base est (>= 5 dB) - SNR_EST_M2M4, // 2nd & 4th moment est (>= 1 dB) - SNR_EST_SVR // SVR-based est (>= 0dB) - } snr_est_type_t; - - /*! \brief A parent class for SNR estimators, specifically for - * M-PSK signals in AWGN channels. - * \ingroup snr_blk - */ - class DIGITAL_API mpsk_snr_est - { - protected: - double d_alpha, d_beta; - - public: - /*! Constructor - * - * Parameters: - * \param alpha: the update rate of internal running average - * calculations. - */ - mpsk_snr_est(double alpha); - virtual ~mpsk_snr_est(); - - //! Get the running-average coefficient - double alpha() const; - - //! Set the running-average coefficient - void set_alpha(double alpha); - - //! Update the current registers - virtual int update(int noutput_items, - const gr_complex *input); - - //! Use the register values to compute a new estimate - virtual double snr(); - }; - - - //! \brief SNR Estimator using simple mean/variance estimates. - /*! \ingroup snr_blk - * - * A very simple SNR estimator that just uses mean and variance - * estimates of an M-PSK constellation. This esimator is quick - * and cheap and accurate for high SNR (above 7 dB or so) but - * quickly starts to overestimate the SNR at low SNR. - */ - class DIGITAL_API mpsk_snr_est_simple : - public mpsk_snr_est - { - private: - double d_y1, d_y2; - - public: - /*! Constructor - * - * Parameters: - * \param alpha: the update rate of internal running average - * calculations. - */ - mpsk_snr_est_simple(double alpha); - ~mpsk_snr_est_simple() {} - - int update(int noutput_items, - const gr_complex *input); - double snr(); - }; - - - //! \brief SNR Estimator using skewness correction. - /*! \ingroup snr_blk - * - * This is an estimator that came from a discussion between Tom - * Rondeau and fred harris with no known paper reference. The - * idea is that at low SNR, the variance estimations will be - * affected because of fold-over around the decision boundaries, - * which results in a skewness to the samples. We estimate the - * skewness and use this as a correcting term. - */ - class DIGITAL_API mpsk_snr_est_skew : - public mpsk_snr_est - { - private: - double d_y1, d_y2, d_y3; - - public: - /*! Constructor - * - * Parameters: - * \param alpha: the update rate of internal running average - * calculations. - */ - mpsk_snr_est_skew(double alpha); - ~mpsk_snr_est_skew() {} - - int update(int noutput_items, - const gr_complex *input); - double snr(); - }; - - - //! \brief SNR Estimator using 2nd and 4th-order moments. - /*! \ingroup snr_blk - * - * An SNR estimator for M-PSK signals that uses 2nd (M2) and 4th - * (M4) order moments. This estimator uses knowledge of the - * kurtosis of the signal (k_a) and noise (k_w) to make its - * estimation. We use Beaulieu's approximations here to M-PSK - * signals and AWGN channels such that k_a=1 and k_w=2. These - * approximations significantly reduce the complexity of the - * calculations (and computations) required. - * - * Reference: - * D. R. Pauluzzi and N. C. Beaulieu, "A comparison of SNR - * estimation techniques for the AWGN channel," IEEE - * Trans. Communications, Vol. 48, No. 10, pp. 1681-1691, 2000. - */ - class DIGITAL_API mpsk_snr_est_m2m4 : - public mpsk_snr_est - { - private: - double d_y1, d_y2; - - public: - /*! Constructor - * - * Parameters: - * \param alpha: the update rate of internal running average - * calculations. - */ - mpsk_snr_est_m2m4(double alpha); - ~mpsk_snr_est_m2m4() {} - - int update(int noutput_items, - const gr_complex *input); - double snr(); - }; - - - //! \brief SNR Estimator using 2nd and 4th-order moments. - /*! \ingroup snr_blk - * - * An SNR estimator for M-PSK signals that uses 2nd (M2) and 4th - * (M4) order moments. This estimator uses knowledge of the - * kurtosis of the signal (k_a) and noise (k_w) to make its - * estimation. In this case, you can set your own estimations for - * k_a and k_w, the kurtosis of the signal and noise, to fit this - * estimation better to your signal and channel conditions. - * - * A word of warning: this estimator has not been fully tested or - * proved with any amount of rigor. The estimation for M4 in - * particular might be ignoring effectf of when k_a and k_w are - * different. Use this estimator with caution and a copy of the - * reference on hand. - * - * The digital_mpsk_snr_est_m2m4 assumes k_a and k_w to simplify - * the computations for M-PSK and AWGN channels. Use that - * estimator unless you have a way to guess or estimate these - * values here. - * - * Original paper: - * R. Matzner, "An SNR estimation algorithm for complex baseband - * signal using higher order statistics," Facta Universitatis - * (Nis), no. 6, pp. 41-52, 1993. - * - * Reference used in derivation: - * D. R. Pauluzzi and N. C. Beaulieu, "A comparison of SNR - * estimation techniques for the AWGN channel," IEEE - * Trans. Communications, Vol. 48, No. 10, pp. 1681-1691, 2000. - */ - class DIGITAL_API snr_est_m2m4 : - public mpsk_snr_est - { - private: - double d_y1, d_y2; - double d_ka, d_kw; - - public: - /*! Constructor - * - * Parameters: - * \param alpha: the update rate of internal running average - * calculations. - * \param ka: estimate of the signal kurtosis (1 for PSK) - * \param kw: estimate of the channel noise kurtosis (2 for AWGN) - */ - snr_est_m2m4(double alpha, double ka, double kw); - ~snr_est_m2m4() {} - - int update(int noutput_items, - const gr_complex *input); - double snr(); - }; - - - //! \brief Signal-to-Variation Ratio SNR Estimator. - /*! \ingroup snr_blk - * - * This estimator actually comes from an SNR estimator for M-PSK - * signals in fading channels, but this implementation is - * specifically for AWGN channels. The math was simplified to - * assume a signal and noise kurtosis (k_a and k_w) for M-PSK - * signals in AWGN. These approximations significantly reduce the - * complexity of the calculations (and computations) required. - * - * Original paper: - * A. L. Brandao, L. B. Lopes, and D. C. McLernon, "In-service - * monitoring of multipath delay and cochannel interference for - * indoor mobile communication systems," Proc. IEEE - * Int. Conf. Communications, vol. 3, pp. 1458-1462, May 1994. - * - * Reference: - * D. R. Pauluzzi and N. C. Beaulieu, "A comparison of SNR - * estimation techniques for the AWGN channel," IEEE - * Trans. Communications, Vol. 48, No. 10, pp. 1681-1691, 2000. - */ - class DIGITAL_API mpsk_snr_est_svr : - public mpsk_snr_est - { - private: - double d_y1, d_y2; - - public: - /*! Constructor - * - * Parameters: - * \param alpha: the update rate of internal running average - * calculations. - */ - mpsk_snr_est_svr(double alpha); - ~mpsk_snr_est_svr() {} - - int update(int noutput_items, - const gr_complex *input); - double snr(); - }; - - } /* namespace digital */ -} /* namespace gr */ - -#endif /* INCLUDED_DIGITAL_MPSK_SNR_EST_H */ |