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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/.
*
*/
#ifndef SRSLTE_DFT_H
#define SRSLTE_DFT_H
#include "srslte/config.h"
#include <stdbool.h>
/**********************************************************************************************
* File: dft.h
*
* Description: Generic DFT module.
* Supports one-dimensional complex and real transforms. Options are set
* using the dft_plan_set_x functions.
*
* Options (default is false):
*
* mirror - Rearranges negative and positive frequency bins. Swaps after
* transform for FORWARD, swaps before transform for BACKWARD.
* db - Provides output in dB (10*log10(x)).
* norm - Normalizes output (by sqrt(len) for complex, len for real).
* dc - Handles insertion and removal of null DC carrier internally.
*
* Reference:
*********************************************************************************************/
#ifdef __cplusplus
extern "C" {
#endif
typedef enum { SRSLTE_DFT_COMPLEX, SRSLTE_REAL } srslte_dft_mode_t;
typedef enum { SRSLTE_DFT_FORWARD, SRSLTE_DFT_BACKWARD } srslte_dft_dir_t;
typedef struct SRSLTE_API {
int init_size; // DFT length used in the first initialization
int size; // DFT length
void* in; // Input buffer
void* out; // Output buffer
void* p; // DFT plan
bool is_guru;
bool forward; // Forward transform?
bool mirror; // Shift negative and positive frequencies?
bool db; // Provide output in dB?
bool norm; // Normalize output?
bool dc; // Handle insertion/removal of null DC carrier internally?
srslte_dft_dir_t dir; // Forward/Backward
srslte_dft_mode_t mode; // Complex/Real
} srslte_dft_plan_t;
SRSLTE_API int srslte_dft_plan(srslte_dft_plan_t* plan, int dft_points, srslte_dft_dir_t dir, srslte_dft_mode_t type);
SRSLTE_API int srslte_dft_plan_c(srslte_dft_plan_t* plan, int dft_points, srslte_dft_dir_t dir);
SRSLTE_API int srslte_dft_plan_guru_c(srslte_dft_plan_t* plan,
int dft_points,
srslte_dft_dir_t dir,
cf_t* in_buffer,
cf_t* out_buffer,
int istride,
int ostride,
int how_many,
int idist,
int odist);
SRSLTE_API int srslte_dft_plan_r(srslte_dft_plan_t* plan, int dft_points, srslte_dft_dir_t dir);
SRSLTE_API int srslte_dft_replan(srslte_dft_plan_t* plan, const int new_dft_points);
SRSLTE_API int srslte_dft_replan_guru_c(srslte_dft_plan_t* plan,
const int new_dft_points,
cf_t* in_buffer,
cf_t* out_buffer,
int istride,
int ostride,
int how_many,
int idist,
int odist);
SRSLTE_API int srslte_dft_replan_c(srslte_dft_plan_t* plan, int new_dft_points);
SRSLTE_API int srslte_dft_replan_r(srslte_dft_plan_t* plan, int new_dft_points);
SRSLTE_API void srslte_dft_plan_free(srslte_dft_plan_t* plan);
/* Set options */
SRSLTE_API void srslte_dft_plan_set_mirror(srslte_dft_plan_t* plan, bool val);
SRSLTE_API void srslte_dft_plan_set_db(srslte_dft_plan_t* plan, bool val);
SRSLTE_API void srslte_dft_plan_set_norm(srslte_dft_plan_t* plan, bool val);
SRSLTE_API void srslte_dft_plan_set_dc(srslte_dft_plan_t* plan, bool val);
/* Compute DFT */
SRSLTE_API void srslte_dft_run(srslte_dft_plan_t* plan, const void* in, void* out);
SRSLTE_API void srslte_dft_run_c_zerocopy(srslte_dft_plan_t* plan, const cf_t* in, cf_t* out);
SRSLTE_API void srslte_dft_run_c(srslte_dft_plan_t* plan, const cf_t* in, cf_t* out);
SRSLTE_API void srslte_dft_run_guru_c(srslte_dft_plan_t* plan);
SRSLTE_API void srslte_dft_run_r(srslte_dft_plan_t* plan, const float* in, float* out);
#ifdef __cplusplus
}
#endif
#endif // SRSLTE_DFT_H