mirror of https://github.com/pvnis/srsRAN_4G.git
You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
114 lines
3.7 KiB
C
114 lines
3.7 KiB
C
/**
|
|
* Copyright 2013-2022 Software Radio Systems Limited
|
|
*
|
|
* This file is part of srsRAN.
|
|
*
|
|
* srsRAN 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.
|
|
*
|
|
* srsRAN 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: resampler.h
|
|
*
|
|
* Description: Linear and vector interpolation
|
|
*
|
|
* Reference:
|
|
*****************************************************************************/
|
|
|
|
#ifndef SRSRAN_RESAMPLER_H
|
|
#define SRSRAN_RESAMPLER_H
|
|
|
|
#include <stdbool.h>
|
|
#include <stdint.h>
|
|
|
|
#include "srsran/config.h"
|
|
#include "srsran/phy/dft/dft.h"
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/**
|
|
* Resampler operating modes
|
|
*/
|
|
typedef enum {
|
|
SRSRAN_RESAMPLER_MODE_INTERPOLATE = 0,
|
|
SRSRAN_RESAMPLER_MODE_DECIMATE,
|
|
} srsran_resampler_mode_t;
|
|
|
|
/**
|
|
* @brief Resampler internal buffers and subcomponents
|
|
*/
|
|
typedef struct {
|
|
srsran_resampler_mode_t mode; ///< Interpolate or decimate mode
|
|
uint32_t ratio; ///< Decimation/Interpolation ratio
|
|
uint32_t window_sz; ///< Maximum number of processed samples
|
|
uint32_t delay; ///< Filter delay in samples
|
|
srsran_dft_plan_t fft; ///< Forward DFT
|
|
srsran_dft_plan_t ifft; ///< Backward DFT
|
|
uint32_t state_len; ///< Number of acccumulated samples in the internal state
|
|
cf_t* in_buffer; ///< DFT input buffer
|
|
cf_t* out_buffer; ///< DFT output buffer
|
|
cf_t* state; ///< Filter state
|
|
cf_t* filter; ///< Frequency domain filter
|
|
} srsran_resampler_fft_t;
|
|
|
|
/**
|
|
* Initialise an FFT based resampler which can be configured as decimator or interpolator.
|
|
* @param q Object pointer
|
|
* @param mode Determines whether the operation mode is decimation or interpolation
|
|
* @param ratio Operational ratio
|
|
* @return SRSRAN_SUCCES if no error, otherwise an SRSRAN error code
|
|
*/
|
|
SRSRAN_API int srsran_resampler_fft_init(srsran_resampler_fft_t* q, srsran_resampler_mode_t mode, uint32_t ratio);
|
|
|
|
/**
|
|
* @brief resets internal re-sampler state
|
|
* @param q Object pointer
|
|
*/
|
|
SRSRAN_API void srsran_resampler_fft_reset_state(srsran_resampler_fft_t* q);
|
|
|
|
/**
|
|
* Get delay from the FFT based resampler.
|
|
* @param q Object pointer
|
|
* @return the delay in number of samples
|
|
*/
|
|
SRSRAN_API uint32_t srsran_resampler_fft_get_delay(srsran_resampler_fft_t* q);
|
|
|
|
/**
|
|
* @brief Run FFT based resampler in the initiated mode.
|
|
*
|
|
* @note Setting the input to NULL is equivalent of feeding zeroes
|
|
* @note Setting the output to NULL is equivalent of dropping output samples
|
|
*
|
|
* @param q Object pointer, make sure it has been initialised
|
|
* @param input Points at the input complex buffer
|
|
* @param output Points at the output complex buffer
|
|
* @param nsamples Number of samples to apply the processing
|
|
*/
|
|
SRSRAN_API void srsran_resampler_fft_run(srsran_resampler_fft_t* q, const cf_t* input, cf_t* output, uint32_t nsamples);
|
|
|
|
/**
|
|
* Free FFT based resampler buffers and subcomponents
|
|
* @param q Object pointer
|
|
*/
|
|
SRSRAN_API void srsran_resampler_fft_free(srsran_resampler_fft_t* q);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif // SRSRAN_RESAMPLER_H
|