/* -*- c++ -*- */ /* * Copyright 2004 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_GR_REMEZ_H #define INCLUDED_GR_REMEZ_H #include #include #include /*! * \brief Parks-McClellan FIR filter design. * * \ingroup filter_design * * Calculates the optimal (in the Chebyshev/minimax sense) FIR filter * inpulse reponse given a set of band edges, the desired reponse on * those bands, and the weight given to the error in those bands. * * \param order filter order (number of taps in the returned filter - 1) * \param bands frequency at the band edges [ b1 e1 b2 e2 b3 e3 ...] * \param ampl desired amplitude at the band edges [ a(b1) a(e1) a(b2) a(e2) ...] * \param error_weight weighting applied to each band (usually 1) * \param filter_type one of "bandpass", "hilbert" or "differentiator" * \param grid_density determines how accurately the filter will be constructed. \ * The minimum value is 16; higher values are slower to compute. * * Frequency is in the range [0, 1], with 1 being the Nyquist frequency (Fs/2) * * \returns vector of computed taps * * \throws std::runtime_error if args are invalid or calculation fails to converge. */ std::vector gr_remez (int order, const std::vector &bands, const std::vector &l, const std::vector &error_weight, const std::string filter_type = "bandpass", int grid_density = 16 ) throw (std::runtime_error); #endif /* INCLUDED_GR_REMEZ_H */