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C

/*
* Copyright 2013-2019 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_WIENER_DL_H_
#define SRSLTE_WIENER_DL_H_
#include <srslte/config.h>
#include <srslte/phy/common/phy_common.h>
#include <srslte/phy/dft/dft.h>
#include <srslte/phy/utils/random.h>
// Constant static parameters
#define SRSLTE_WIENER_DL_HLS_FIFO_SIZE (8U)
#define SRSLTE_WIENER_DL_MIN_PRB (4U)
#define SRSLTE_WIENER_DL_MIN_RE (SRSLTE_WIENER_DL_MIN_PRB * SRSLTE_NRE)
#define SRSLTE_WIENER_DL_MIN_REF (SRSLTE_WIENER_DL_MIN_PRB * 2U)
#define SRSLTE_WIENER_DL_TFIFO_SIZE (2U)
#define SRSLTE_WIENER_DL_XFIFO_SIZE (400U)
#define SRSLTE_WIENER_DL_TIMEFIFO_SIZE (32U)
#define SRSLTE_WIENER_DL_CXFIFO_SIZE (400U)
typedef struct {
cf_t* hls_fifo_1[SRSLTE_WIENER_DL_HLS_FIFO_SIZE]; // Least square channel estimates on odd pilots
cf_t* hls_fifo_2[SRSLTE_WIENER_DL_HLS_FIFO_SIZE]; // Least square channel estimates on even pilots
cf_t* tfifo[SRSLTE_WIENER_DL_TFIFO_SIZE]; // memory for time domain channel linear interpolation
cf_t* xfifo[SRSLTE_WIENER_DL_XFIFO_SIZE]; // fifo for averaging the frequency correlation vectors
cf_t cV[SRSLTE_WIENER_DL_MIN_RE]; // frequency correlation vector among all subcarriers
float deltan; // step within time domain linear interpolation
uint32_t nfifosamps; // number of samples inside the fifo for averaging the correlation vectors
float invtpilotoff; // step for time domain linear interpolation
cf_t* timefifo; // fifo for storing single frequency channel time domain evolution
cf_t* cxfifo[SRSLTE_WIENER_DL_CXFIFO_SIZE]; // fifo for averaging time domain channel correlation vector
uint32_t sumlen; // length of dynamic average window for time domain channel correlation vector
uint32_t skip; // pilot OFDM symbols to skip when training Wiener matrices (skip = 1,..,4)
uint32_t cnt; // counter for skipping pilot OFDM symbols
} srslte_wiener_dl_state_t;
typedef struct {
// Maximum allocated number of...
uint32_t max_prb; // Resource Blocks
uint32_t max_ref; // Reference signals
uint32_t max_re; // Resource Elements (equivalent to sub-carriers)
uint32_t max_tx_ports; // Tx Ports
uint32_t max_rx_ant; // Rx Antennas
// Configured number of...
uint32_t nof_prb; // Resource Blocks
uint32_t nof_ref; // Reference signals
uint32_t nof_re; // Resource Elements (equivalent to sub-carriers)
uint32_t nof_tx_ports; // Tx Ports
uint32_t nof_rx_ant; // Rx Antennas
// One state per possible channel (allocated in init)
srslte_wiener_dl_state_t* state[SRSLTE_MAX_PORTS][SRSLTE_MAX_PORTS];
// Wiener matrices
cf_t wm1[SRSLTE_WIENER_DL_MIN_RE][SRSLTE_WIENER_DL_MIN_REF];
cf_t wm2[SRSLTE_WIENER_DL_MIN_RE][SRSLTE_WIENER_DL_MIN_REF];
bool wm_computed;
bool ready;
// Calculation support
cf_t hlsv[SRSLTE_WIENER_DL_MIN_RE];
cf_t hlsv_sum[SRSLTE_WIENER_DL_MIN_RE];
cf_t acV[SRSLTE_WIENER_DL_MIN_RE];
union {
cf_t m[SRSLTE_WIENER_DL_MIN_REF][SRSLTE_WIENER_DL_MIN_REF];
cf_t v[SRSLTE_WIENER_DL_MIN_REF * SRSLTE_WIENER_DL_MIN_REF];
} RH;
union {
cf_t m[SRSLTE_WIENER_DL_MIN_REF][SRSLTE_WIENER_DL_MIN_REF];
cf_t v[SRSLTE_WIENER_DL_MIN_REF * SRSLTE_WIENER_DL_MIN_REF];
} invRH;
cf_t hH1[SRSLTE_WIENER_DL_MIN_RE][SRSLTE_WIENER_DL_MIN_REF];
cf_t hH2[SRSLTE_WIENER_DL_MIN_RE][SRSLTE_WIENER_DL_MIN_REF];
// Temporal vector
cf_t* tmp;
// Random generator
srslte_random_t random;
// FFT/iFFT
srslte_dft_plan_t fft;
srslte_dft_plan_t ifft;
cf_t filter[SRSLTE_WIENER_DL_MIN_RE];
// Matrix inverter
void* matrix_inverter;
} srslte_wiener_dl_t;
SRSLTE_API int
srslte_wiener_dl_init(srslte_wiener_dl_t* q, uint32_t max_prb, uint32_t max_tx_ports, uint32_t max_rx_ant);
SRSLTE_API int srslte_wiener_dl_set_cell(srslte_wiener_dl_t* q, srslte_cell_t cell);
SRSLTE_API void srslte_wiener_dl_reset(srslte_wiener_dl_t* q);
SRSLTE_API int srslte_wiener_dl_run(srslte_wiener_dl_t* q,
uint32_t tx,
uint32_t rx,
uint32_t m,
uint32_t shift,
cf_t* pilots,
cf_t* estimated,
float snr_lin);
SRSLTE_API void srslte_wiener_dl_free(srslte_wiener_dl_t* q);
#endif // SRSLTE_WIENER_DL_H_