OpenRTX/tests/unit/M17_rrc.cpp

60 wiersze
2.4 KiB
C++

/***************************************************************************
* Copyright (C) 2021 by Federico Amedeo Izzo IU2NUO, *
* Niccolò Izzo IU2KIN *
* Frederik Saraci IU2NRO *
* Silvano Seva IU2KWO *
* *
* *
* This program 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 of the License, or *
* (at your option) any later version. *
* *
* This program 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 this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#include <limits.h>
#include <inttypes.h>
#include <stdio.h>
#include <M17/M17DSP.h>
#define IMPULSE_SIZE 4096
using namespace std;
/**
* Test the different demodulation steps
*/
int main()
{
// Open file
FILE *baseband_out = fopen("M17_rrc_impulse_response.raw", "wb");
if (!baseband_out)
{
perror("Error in opening output file");
return -1;
}
// Allocate impulse signal
int16_t impulse[IMPULSE_SIZE] = { 0 };
impulse[0] = SHRT_MAX;
// Apply RRC on impulse signal
int16_t filtered_impulse[IMPULSE_SIZE] = { 0 };
for(size_t i = 0; i < IMPULSE_SIZE; i++)
{
float elem = static_cast< float >(impulse[i]);
filtered_impulse[i] = static_cast< int16_t >(M17::rrc(0.10 * elem));
}
fwrite(filtered_impulse, IMPULSE_SIZE, 1, baseband_out);
fclose(baseband_out);
return 0;
}