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https://github.com/VK3FNG/soundmodem.git
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57 lines
1.7 KiB
C
57 lines
1.7 KiB
C
/*****************************************************************************/
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/*
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* fskic.c -- DF9IC FSK Modem filter curves.
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*
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* Copyright (C) 2003
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* Thomas Sailer (t.sailer@alumni.ethz.ch)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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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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*
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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., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*
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*/
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/*****************************************************************************/
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#include "modem.h"
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#include "raisedcosine.h"
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#include "fskic.h"
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/* --------------------------------------------------------------------- */
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double df9ic_rxfilter(double t)
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{
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unsigned int i;
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double sum = 0;
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t *= FSKIC_RXOVER;
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t += 0.5 * sizeof(fskic_rxpulse) / sizeof(fskic_rxpulse[0]);
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for (i = 0; i < sizeof(fskic_rxpulse) / sizeof(fskic_rxpulse[0]); i++)
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sum += fskic_rxpulse[i] * sinc(i - t);
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return sum;
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}
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double df9ic_txfilter(double t)
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{
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unsigned int i;
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double sum = 0;
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t *= FSKIC_TXOVER;
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t += 0.5 * sizeof(fskic_txpulse) / sizeof(fskic_txpulse[0]);
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for (i = 0; i < sizeof(fskic_txpulse) / sizeof(fskic_txpulse[0]); i++)
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sum += fskic_txpulse[i] * sinc(i - t);
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return sum;
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}
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