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C

/**
* Copyright 2013-2021 Software Radio Systems Limited
*
* This file is part of srsLTE.
*
* srsLTE is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* srsLTE 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 Affero General Public License for more details.
*
* A copy of the GNU Affero General Public License can be found in
* the LICENSE file in the top-level directory of this distribution
* and at http://www.gnu.org/licenses/.
*
*/
/******************************************************************************
* File: cfo.h
*
* Description: Carrier frequency offset correction using complex exponentials.
*
* Reference:
*****************************************************************************/
#ifndef SRSLTE_CFO_H
#define SRSLTE_CFO_H
#include <complex.h>
#include "srslte/config.h"
#include "srslte/phy/utils/cexptab.h"
#include "srslte/phy/common/phy_common.h"
#define SRSLTE_CFO_CEXPTAB_SIZE 4096
typedef struct SRSLTE_API {
float last_freq;
float tol;
int nsamples;
int max_samples;
srslte_cexptab_t tab;
cf_t* cur_cexp;
} srslte_cfo_t;
SRSLTE_API int srslte_cfo_init(srslte_cfo_t* h, uint32_t nsamples);
SRSLTE_API void srslte_cfo_free(srslte_cfo_t* h);
SRSLTE_API int srslte_cfo_resize(srslte_cfo_t* h, uint32_t samples);
SRSLTE_API void srslte_cfo_set_tol(srslte_cfo_t* h, float tol);
SRSLTE_API void srslte_cfo_correct(srslte_cfo_t* h, const cf_t* input, cf_t* output, float freq);
SRSLTE_API void
srslte_cfo_correct_offset(srslte_cfo_t* h, const cf_t* input, cf_t* output, float freq, int cexp_offset, int nsamples);
SRSLTE_API float srslte_cfo_est_corr_cp(cf_t* input_buffer, uint32_t nof_prb);
#endif // SRSLTE_CFO_H