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.
88 lines
3.3 KiB
C
88 lines
3.3 KiB
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_FADING_H
|
|
#define SRSLTE_FADING_H
|
|
|
|
#include "srslte/config.h"
|
|
#include "srslte/phy/common/timestamp.h"
|
|
#include "srslte/phy/dft/dft.h"
|
|
#include <inttypes.h>
|
|
#include <stdint.h>
|
|
|
|
#define SRSLTE_CHANNEL_FADING_MAXTAPS 9
|
|
#define SRSLTE_CHANNEL_FADING_NTERMS 16
|
|
|
|
typedef enum {
|
|
srslte_channel_fading_model_none = 0,
|
|
srslte_channel_fading_model_epa,
|
|
srslte_channel_fading_model_eva,
|
|
srslte_channel_fading_model_etu,
|
|
} srslte_channel_fading_model_t;
|
|
|
|
typedef struct {
|
|
// Configuration parameters
|
|
float srate; // Sampling rate: 1.92e6, 3.84e6, ..., 23.04e6, 30.72e6
|
|
srslte_channel_fading_model_t model; // None, EPA, EVA, ETU
|
|
float doppler; // Maximum doppler: 5, 70, 300
|
|
|
|
// Internal tap parametrisation
|
|
uint32_t N; // FFT size
|
|
uint32_t path_delay; // Path delay
|
|
uint32_t state_len; // Length of the impulse response saved in the state
|
|
|
|
float coeff_alpha[SRSLTE_CHANNEL_FADING_MAXTAPS][SRSLTE_CHANNEL_FADING_NTERMS]; // Angle of arrival
|
|
float coeff_a[SRSLTE_CHANNEL_FADING_MAXTAPS][SRSLTE_CHANNEL_FADING_NTERMS]; // Random phase
|
|
float coeff_b[SRSLTE_CHANNEL_FADING_MAXTAPS][SRSLTE_CHANNEL_FADING_NTERMS]; // Random phase
|
|
cf_t* h_tap[SRSLTE_CHANNEL_FADING_MAXTAPS]; // Static tap signal in frequency domain
|
|
|
|
// Utils
|
|
srslte_dft_plan_t fft; // DFT to frequency domain
|
|
srslte_dft_plan_t ifft; // DFT to time domain
|
|
cf_t* temp; // Temporal buffer, length fft_size
|
|
cf_t* h_freq; // Channel frequency response, length fft_size
|
|
cf_t* y_freq; // Intermediate frequency domain buffer
|
|
float sin_table[1024]; // Table of sinus values
|
|
|
|
// State variables
|
|
cf_t* state; // To save impulse response of the filter
|
|
} srslte_channel_fading_t;
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
SRSLTE_API int srslte_channel_fading_init(srslte_channel_fading_t* q, double srate, const char* model, uint32_t seed);
|
|
|
|
SRSLTE_API void srslte_channel_fading_free(srslte_channel_fading_t* q);
|
|
|
|
SRSLTE_API double srslte_channel_fading_execute(srslte_channel_fading_t* q,
|
|
const cf_t* in,
|
|
cf_t* out,
|
|
uint32_t nof_samples,
|
|
double init_time);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif // SRSLTE_FADING_H
|