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C

/*
* Copyright (c) 2013, Ismael Gomez-Miguelez <gomezi@tcd.ie>.
* This file is part of OSLD-lib (http://https://github.com/ismagom/osld-lib)
*
* OSLD-lib is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* OSLD-lib 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with OSLD-lib. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef DEMOD_SOFT_
#define DEMOD_SOFT_
#include <complex.h>
#include <stdint.h>
#include "modem_table.h"
enum alg { EXACT, APPROX };
typedef struct {
float sigma; // noise power
enum alg alg_type; // soft demapping algorithm (EXACT or APPROX)
modem_table_t *table; // symbol mapping table (see modem_table.h)
}demod_soft_t;
void demod_soft_init(demod_soft_t *q);
void demod_soft_table_set(demod_soft_t *q, modem_table_t *table);
void demod_soft_alg_set(demod_soft_t *q, enum alg alg_type);
void demod_soft_sigma_set(demod_soft_t *q, float sigma);
int demod_soft_demodulate(demod_soft_t *q, const cf* symbols, float* llr, int nsymbols);
/* High-level API */
typedef struct {
demod_soft_t obj;
modem_table_t table;
struct demod_soft_init {
enum modem_std std; // symbol mapping standard (see modem_table.h)
} init;
const cf* input;
int in_len;
struct demod_soft_ctrl_in {
float sigma; // Estimated noise variance
enum alg alg_type; // soft demapping algorithm (EXACT or APPROX)
}ctrl_in;
float* output;
int out_len;
}demod_soft_hl;
int demod_soft_initialize(demod_soft_hl* hl);
int demod_soft_work(demod_soft_hl* hl);
int demod_soft_stop(demod_soft_hl* hl);
#endif