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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: ssss.h
*
* Description: Secondary sidelink synchronization signal (SSSS) generation and detection.
*
*
* Reference: 3GPP TS 36.211 version 15.6.0 Release 15 Sec. 9.7.2
*****************************************************************************/
#ifndef SRSLTE_SSSS_H
#define SRSLTE_SSSS_H
#include <stdbool.h>
#include <stdint.h>
#include "srslte/phy/common/phy_common_sl.h"
#include "srslte/phy/dft/dft.h"
#define SRSLTE_SSSS_NOF_SEQ 336
#define SRSLTE_SSSS_N 31
#define SRSLTE_SSSS_LEN 2 * SRSLTE_SSSS_N
typedef struct SRSLTE_API {
float ssss_signal[SRSLTE_SSSS_NOF_SEQ][SRSLTE_SSSS_LEN]; // One sequence for each N_sl_id
cf_t** ssss_sf_freq;
cf_t* input_pad_freq;
cf_t* input_pad_time;
cf_t* dot_prod_output;
cf_t* dot_prod_output_time;
cf_t* shifted_output;
float* shifted_output_abs;
int32_t corr_peak_pos;
float corr_peak_value;
uint32_t N_sl_id;
srslte_dft_plan_t plan_input;
srslte_dft_plan_t plan_out;
} srslte_ssss_t;
SRSLTE_API int srslte_ssss_init(srslte_ssss_t* q, uint32_t nof_prb, srslte_cp_t cp, srslte_sl_tm_t tm);
SRSLTE_API void srslte_ssss_generate(float* ssss_signal, uint32_t N_sl_id, srslte_sl_tm_t tm);
SRSLTE_API void srslte_ssss_put_sf_buffer(float* ssss_signal, cf_t* sf_buffer, uint32_t nof_prb, srslte_cp_t cp);
SRSLTE_API int srslte_ssss_find(srslte_ssss_t* q, cf_t* input, uint32_t nof_prb, uint32_t N_id_2, srslte_cp_t cp);
SRSLTE_API void srslte_ssss_free(srslte_ssss_t* q);
#endif