mirror of
https://github.com/f4exb/sdrangel.git
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160 lines
4.6 KiB
C++
160 lines
4.6 KiB
C++
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/* iir.c
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This file is part of a program that implements a Software-Defined Radio.
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Copyright (C) 2014, 2022, 2023 Warren Pratt, NR0V
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Copyright (C) 2024 Edouard Griffiths, F4EXB Adapted to SDRangel
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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The author can be reached by email at
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warren@wpratt.com
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*/
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#include "comm.hpp"
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#include "bqbp.hpp"
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#include "RXA.hpp"
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#include "TXA.hpp"
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namespace WDSP {
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/********************************************************************************************************
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* *
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* Complex Bi-Quad Band-Pass *
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* *
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********************************************************************************************************/
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void BQBP::calc_bqbp(BQBP *a)
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{
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double f0, w0, bw, q, sn, cs, c, den;
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bw = a->f_high - a->f_low;
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f0 = (a->f_high + a->f_low) / 2.0;
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q = f0 / bw;
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w0 = TWOPI * f0 / a->rate;
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sn = sin(w0);
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cs = cos(w0);
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c = sn / (2.0 * q);
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den = 1.0 + c;
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a->a0 = +c / den;
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a->a1 = 0.0;
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a->a2 = -c / den;
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a->b1 = 2.0 * cs / den;
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a->b2 = (c - 1.0) / den;
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flush_bqbp(a);
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}
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BQBP* BQBP::create_bqbp(int run, int size, float* in, float* out, double rate, double f_low, double f_high, double gain, int nstages)
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{
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BQBP *a = new BQBP;
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a->run = run;
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a->size = size;
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a->in = in;
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a->out = out;
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a->rate = rate;
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a->f_low = f_low;
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a->f_high = f_high;
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a->gain = gain;
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a->nstages = nstages;
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a->x0 = new double[a->nstages * 2]; // (float*)malloc0(a->nstages * sizeof(complex));
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a->x1 = new double[a->nstages * 2]; // (float*)malloc0(a->nstages * sizeof(complex));
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a->x2 = new double[a->nstages * 2]; // (float*)malloc0(a->nstages * sizeof(complex));
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a->y0 = new double[a->nstages * 2]; // (float*)malloc0(a->nstages * sizeof(complex));
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a->y1 = new double[a->nstages * 2]; // (float*)malloc0(a->nstages * sizeof(complex));
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a->y2 = new double[a->nstages * 2]; // (float*)malloc0(a->nstages * sizeof(complex));
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calc_bqbp(a);
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return a;
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}
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void BQBP::destroy_bqbp(BQBP *a)
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{
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delete[](a->y2);
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delete[](a->y1);
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delete[](a->y0);
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delete[](a->x2);
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delete[](a->x1);
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delete[](a->x0);
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delete(a);
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}
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void BQBP::flush_bqbp(BQBP *a)
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{
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int i;
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for (i = 0; i < a->nstages; i++)
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{
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a->x1[2 * i + 0] = a->x2[2 * i + 0] = a->y1[2 * i + 0] = a->y2[2 * i + 0] = 0.0;
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a->x1[2 * i + 1] = a->x2[2 * i + 1] = a->y1[2 * i + 1] = a->y2[2 * i + 1] = 0.0;
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}
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}
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void BQBP::xbqbp(BQBP *a)
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{
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if (a->run)
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{
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int i, j, n;
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for (i = 0; i < a->size; i++)
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{
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for (j = 0; j < 2; j++)
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{
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a->x0[j] = a->gain * a->in[2 * i + j];
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for (n = 0; n < a->nstages; n++)
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{
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if (n > 0)
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a->x0[2 * n + j] = a->y0[2 * (n - 1) + j];
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a->y0[2 * n + j] = a->a0 * a->x0[2 * n + j]
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+ a->a1 * a->x1[2 * n + j]
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+ a->a2 * a->x2[2 * n + j]
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+ a->b1 * a->y1[2 * n + j]
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+ a->b2 * a->y2[2 * n + j];
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a->y2[2 * n + j] = a->y1[2 * n + j];
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a->y1[2 * n + j] = a->y0[2 * n + j];
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a->x2[2 * n + j] = a->x1[2 * n + j];
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a->x1[2 * n + j] = a->x0[2 * n + j];
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}
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a->out[2 * i + j] = a->y0[2 * (a->nstages - 1) + j];
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}
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}
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}
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else if (a->out != a->in)
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{
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std::copy(a->in, a->in + a->size * 2, a->out);
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}
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}
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void BQBP::setBuffers_bqbp(BQBP *a, float* in, float* out)
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{
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a->in = in;
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a->out = out;
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}
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void BQBP::setSamplerate_bqbp(BQBP *a, int rate)
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{
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a->rate = rate;
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calc_bqbp(a);
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}
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void BQBP::setSize_bqbp(BQBP *a, int size)
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{
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a->size = size;
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flush_bqbp(a);
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}
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} // namespace WDSP
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