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Initial Wiener channel estimator

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Xavier Arteaga 5 years ago committed by Xavier Arteaga
parent 96f565d4f2
commit fe141dc002
3 changed files with 649 additions and 0 deletions
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105
lib/include/srslte/phy/ch_estimation/wiener_dl.h
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/*
* 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_SRSLTE_WIENER_DL_H_
#define SRSLTE_SRSLTE_WIENER_DL_H_
#include <srslte/srslte.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; // fifo for averaging the frequency correlation vectors
cf_t *cV; // 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];
cf_t hlsv[SRSLTE_WIENER_DL_MIN_RE];
cf_t hlsv_sum[SRSLTE_WIENER_DL_MIN_RE];
// Temporal vector
cf_t *tmp;
// Random generator
srslte_random_t random;
} 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, const 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_SRSLTE_WIENER_DL_H_

1
lib/include/srslte/srslte.h
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@ -48,6 +48,7 @@ extern "C" {
#include "srslte/phy/ch_estimation/chest_dl.h" #include "srslte/phy/ch_estimation/chest_dl.h"
#include "srslte/phy/ch_estimation/chest_ul.h" #include "srslte/phy/ch_estimation/chest_ul.h"
#include "srslte/phy/ch_estimation/wiener_dl.h"
#include "srslte/phy/ch_estimation/refsignal_dl.h" #include "srslte/phy/ch_estimation/refsignal_dl.h"
#include "srslte/phy/ch_estimation/refsignal_ul.h" #include "srslte/phy/ch_estimation/refsignal_ul.h"

543
lib/src/phy/ch_estimation/wiener_dl.c
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/*
* 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/.
*
*/
#include <srslte/srslte.h>
#include <assert.h>
// Useful macros
#define NSAMPLES2NBYTES(N) (sizeof(cf_t) * (N))
#define M_1_3 0.33333333333333333333f /* 1 / 3 */
#define M_1_4 0.25f /* 1 / 4 */
#define M_4_7 0.571428571f /* 4 / 7*/
// Local state function prototypes
static srslte_wiener_dl_state_t* srslte_wiener_dl_state_malloc(srslte_wiener_dl_t *q);
static void srslte_wiener_dl_state_free(srslte_wiener_dl_state_t *q);
static void srslte_wiener_dl_state_reset(srslte_wiener_dl_t *q, srslte_wiener_dl_state_t *state);
// Local run function prototypes
static void srslte_wiener_dl_run_symbol_1_8(srslte_wiener_dl_t *q,
srslte_wiener_dl_state_t *state,
cf_t *pilots,
float snr_lin);
static void srslte_wiener_dl_run_symbol_2_9(srslte_wiener_dl_t *q,
srslte_wiener_dl_state_t *state);
static void srslte_wiener_dl_run_symbol_5_12(srslte_wiener_dl_t *q,
srslte_wiener_dl_state_t *state,
cf_t *pilots,
uint32_t shift);
// Local state related functions
static srslte_wiener_dl_state_t* srslte_wiener_dl_state_malloc(srslte_wiener_dl_t *q) {
// Allocate Channel state
srslte_wiener_dl_state_t* state = calloc(sizeof(srslte_wiener_dl_state_t), 1);
// Check allocation
if (!state) {
perror("malloc");
} else {
int ret = SRSLTE_SUCCESS;
// Allocate state variables
for (int i = 0; i < SRSLTE_WIENER_DL_HLS_FIFO_SIZE && !ret; i++) {
state->hls_fifo_1[i] = srslte_vec_malloc(NSAMPLES2NBYTES(q->max_ref));
if (!state->hls_fifo_1[i]) {
perror("malloc");
ret = SRSLTE_ERROR;
}
if (!ret) {
state->hls_fifo_2[i] = srslte_vec_malloc(NSAMPLES2NBYTES(q->max_ref));
if (!state->hls_fifo_2[i]) {
perror("malloc");
ret = SRSLTE_ERROR;
}
}
}
for(uint32_t i = 0; i < SRSLTE_WIENER_DL_TFIFO_SIZE && !ret; i++) {
state->tfifo[i] = srslte_vec_malloc(NSAMPLES2NBYTES(q->max_re));
if (!state->tfifo[i]) {
perror("malloc");
ret = SRSLTE_ERROR;
}
}
if (!ret) {
state->xfifo = srslte_vec_malloc(NSAMPLES2NBYTES(SRSLTE_WIENER_DL_MIN_RE * SRSLTE_WIENER_DL_XFIFO_SIZE));
if (!state->xfifo) {
perror("malloc");
ret = SRSLTE_ERROR;
}
}
if (!ret) {
state->cV = srslte_vec_malloc(NSAMPLES2NBYTES(SRSLTE_WIENER_DL_MIN_RE));
if (!state->cV) {
perror("malloc");
ret = SRSLTE_ERROR;
}
}
if (!ret) {
state->timefifo = srslte_vec_malloc(NSAMPLES2NBYTES(SRSLTE_WIENER_DL_TIMEFIFO_SIZE));
if (!state->timefifo) {
perror("malloc");
ret = SRSLTE_ERROR;
}
}
for (uint32_t i = 0; i < SRSLTE_WIENER_DL_CXFIFO_SIZE && !ret; i++) {
state->cxfifo[i] = srslte_vec_malloc(NSAMPLES2NBYTES(SRSLTE_WIENER_DL_TFIFO_SIZE));
if (!state->cxfifo[i]) {
perror("malloc");
ret = SRSLTE_ERROR;
}
}
// Initialise the rest
state->deltan = 0.0f;
state->nfifosamps = 0;
state->invtpilotoff = 0;
state->sumlen = 0;
state->skip = 0;
state->cnt = 0;
if (ret) {
// Free all allocated memory
srslte_wiener_dl_state_free(state);
// Return NULL if error
state = NULL;
}
}
return state;
}
static void srslte_wiener_dl_state_reset(srslte_wiener_dl_t *q, srslte_wiener_dl_state_t *state) {
if (q && state) {
// Initialise memory
for (uint32_t i = 0; i < SRSLTE_WIENER_DL_HLS_FIFO_SIZE; i++) {
bzero(state->hls_fifo_1[i], NSAMPLES2NBYTES(q->nof_ref));
bzero(state->hls_fifo_2[i], NSAMPLES2NBYTES(q->nof_ref));
}
for (uint32_t i = 0; i < SRSLTE_WIENER_DL_TFIFO_SIZE; i++) {
bzero(state->tfifo[i], NSAMPLES2NBYTES(q->nof_re));
}
bzero(state->xfifo, NSAMPLES2NBYTES(SRSLTE_WIENER_DL_MIN_RE * SRSLTE_WIENER_DL_XFIFO_SIZE));
bzero(state->cV, NSAMPLES2NBYTES(SRSLTE_WIENER_DL_MIN_RE));
bzero(state->timefifo, NSAMPLES2NBYTES(SRSLTE_WIENER_DL_TIMEFIFO_SIZE));
for (uint32_t i = 0; i < SRSLTE_WIENER_DL_CXFIFO_SIZE; i++) {
bzero(state->cxfifo[i], NSAMPLES2NBYTES(SRSLTE_WIENER_DL_TFIFO_SIZE));
}
// Initialise counters and variables
state->deltan = 0.0f;
state->nfifosamps = 0;
state->invtpilotoff = 0;
state->sumlen = 0;
state->skip = 0;
state->cnt = 0;
}
}
static void srslte_wiener_dl_state_free(srslte_wiener_dl_state_t *q) {
if (q) {
for (int i = 0; i < SRSLTE_WIENER_DL_HLS_FIFO_SIZE; i++) {
if (q->hls_fifo_1[i]) {
free(q->hls_fifo_1[i]);
}
if (q->hls_fifo_2[i]) {
free(q->hls_fifo_2[i]);
}
}
for (uint32_t i = 0; i < SRSLTE_WIENER_DL_TFIFO_SIZE; i++) {
if (q->tfifo[i]) {
free(q->tfifo[i]);
}
}
if (q->xfifo) {
free(q->xfifo);
}
for(uint32_t i = 0; i < SRSLTE_WIENER_DL_CXFIFO_SIZE; i++) {
if (q->cxfifo[i]) {
free(q->cxfifo[i]);
}
}
if (q->cV) {
free(q->cV);
}
if (q->timefifo) {
free(q->timefifo);
}
// Free state
free(q);
}
}
int srslte_wiener_dl_init(srslte_wiener_dl_t *q, uint32_t max_prb, uint32_t max_tx_ports, uint32_t max_rx_ant) {
int ret = SRSLTE_SUCCESS;
if (q && max_prb > SRSLTE_MAX_PRB && max_tx_ports > SRSLTE_MAX_PORTS && max_rx_ant > SRSLTE_MAX_PORTS) {
// Bzero structure
bzero(q, sizeof(srslte_wiener_dl_t));
// Set maximum parameters
q->max_prb = max_prb;
q->max_ref = max_prb * 2;
q->max_re = max_prb * SRSLTE_NRE;
q->max_tx_ports = max_tx_ports;
q->max_rx_ant= max_rx_ant;
// Allocate state
for(uint32_t tx = 0; tx < q->max_tx_ports && !ret; tx++) {
for(uint32_t rx = 0; rx < q->max_tx_ports && !ret; rx++) {
srslte_wiener_dl_state_t* state = srslte_wiener_dl_state_malloc(q);
if (!state) {
perror("srslte_wiener_dl_state_malloc");
ret = SRSLTE_ERROR;
} else {
q->state[tx][rx] = state;
}
}
}
// Allocate temporal buffers, maximum SF size
if (!ret) {
q->tmp = srslte_vec_malloc(NSAMPLES2NBYTES(SRSLTE_SF_LEN_MAX));
if (!q->tmp) {
perror("malloc");
ret = SRSLTE_ERROR;
}
}
if (!ret) {
q->random = srslte_random_init(0xdead);
if (!q->random) {
perror("srslte_random_init");
ret = SRSLTE_ERROR;
}
}
}
return ret;
}
int srslte_wiener_dl_set_cell(srslte_wiener_dl_t *q, const srslte_cell_t *cell) {
int ret = SRSLTE_ERROR_INVALID_INPUTS;
if (q && cell) {
// No invalid inputs
ret = SRSLTE_SUCCESS;
// Set new values
q->nof_prb = cell->nof_prb;
q->nof_ref = cell->nof_prb * 2;
q->nof_re = cell->nof_prb * SRSLTE_NRE;
q->nof_tx_ports = cell->nof_ports;
// Reset states
srslte_wiener_dl_reset(q);
}
return ret;
}
void srslte_wiener_dl_reset(srslte_wiener_dl_t *q) {
if (q) {
// Reset states
for (uint32_t tx = 0; tx < SRSLTE_MAX_PORTS; tx++) {
for (uint32_t rx = 0; rx < SRSLTE_MAX_PORTS; rx++) {
if (q->state[tx][rx]) {
srslte_wiener_dl_state_reset(q, q->state[tx][rx]);
}
}
}
// Reset wiener
bzero(q->wm1, NSAMPLES2NBYTES(SRSLTE_WIENER_DL_MIN_REF * SRSLTE_WIENER_DL_MIN_RE));
bzero(q->wm2, NSAMPLES2NBYTES(SRSLTE_WIENER_DL_MIN_REF * SRSLTE_WIENER_DL_MIN_RE));
}
}
static void circshift_dim1(cf_t **matrix, uint32_t ndim1, int32_t k) {
// Wrap k
k = (k + ndim1) % ndim1;
// Run k times
while(k--) {
// Save first pointer
cf_t *tmp_ptr = matrix[0];
// Shift pointers one position
for (int i = 0; i < ndim1 - 1; i++) {
matrix[i] = matrix[i + 1];
}
// Save last pointer
matrix[ndim1 - 1] = tmp_ptr;
}
}
static void circshift_dim2(cf_t **matrix, uint32_t ndim1, uint32_t ndim2, int32_t k) {
// Wrap k
k = (k + ndim1) % ndim1;
for(uint32_t dim1 = 0; dim1 < ndim1; dim1++) {
// Run k times
for(int i = 0; i < k; i++) {
// Save first value
cf_t tmp = matrix[dim1][0];
// Shift one position
for (int dim2 = 0; i < dim2 - 1; dim2++) {
matrix[dim1][dim2] = matrix[dim1][dim2 + 1];
}
// Save last value
matrix[ndim1][ndim2 - 1] = tmp;
}
}
}
static void matrix_acc_dim1_cc(cf_t **matrix, cf_t *res, uint32_t ndim1, uint32_t ndim2) {
// Accumulate each column
for (uint32_t dim2 = 0; dim2 < ndim2; dim2++) {
cf_t acc = 0.0f;
for (uint32_t dim1 = 0; dim1 < ndim1; dim1++) {
acc += matrix[dim1][dim2];
}
res[dim2] = acc;
}
}
static uint32_t matrix_acc_dim2_cc(cf_t **matrix, cf_t *res, uint32_t ndim1, uint32_t ndim2) {
// Accumulate each row
for (uint32_t dim1 = 0; dim1 < ndim1; dim1++) {
res[dim1] = srslte_vec_acc_cc(matrix[dim1], ndim2);
}
}
static uint32_t vec_find_first_smaller_than_cf(cf_t *x, float y, uint32_t n, uint32_t pos) {
uint32_t ret = n;
for(uint32_t i = pos; i < n && ret == n; i++) {
if (cabsf(x[i]) > y) {
ret = i;
}
}
return ret;
}
static void estimate_wiener(srslte_wiener_dl_t *q, const cf_t wm[SRSLTE_WIENER_DL_MIN_RE][SRSLTE_WIENER_DL_MIN_REF], cf_t *ref, cf_t *h) {
uint32_t r_offset = 0; // Resource Element indexing offset
uint32_t p_offset = 0; // Pilot indexing offset
// Estimate lower band
for(uint32_t i = 0; i < SRSLTE_WIENER_DL_MIN_RE; i++) {
h[r_offset + i] = srslte_vec_dot_prod_ccc(&ref[p_offset], wm[i], SRSLTE_WIENER_DL_MIN_REF);
}
// Estimate Upper band (it might overlap in 6PRB cells with the lower band)
r_offset = q->nof_re - SRSLTE_WIENER_DL_MIN_RE;
p_offset = q->nof_ref - SRSLTE_WIENER_DL_MIN_REF;
for(uint32_t i = 0; i < SRSLTE_WIENER_DL_MIN_RE; i++) {
h[r_offset + i] = srslte_vec_dot_prod_ccc(&ref[p_offset], wm[i], SRSLTE_WIENER_DL_MIN_REF);
}
// Estimate center Resource elements
if (q->nof_re > 2 * SRSLTE_WIENER_DL_MIN_RE) {
for (uint32_t prb = SRSLTE_WIENER_DL_MIN_PRB / 2; prb < q->nof_prb - SRSLTE_WIENER_DL_MIN_REF/2; prb += SRSLTE_WIENER_DL_MIN_PRB / 2) {
uint32_t ref_idx = prb * 2 - SRSLTE_WIENER_DL_MIN_REF / 2;
uint32_t re_idx = prb * SRSLTE_NRE;
for (uint32_t i = SRSLTE_WIENER_DL_MIN_RE / 4; i < (3 * SRSLTE_WIENER_DL_MIN_RE) / 4; i++) {
h[re_idx + i] = srslte_vec_dot_prod_ccc(&ref[ref_idx], wm[i], SRSLTE_WIENER_DL_MIN_REF);
}
}
}
}
static void srslte_wiener_dl_run_symbol_1_8(srslte_wiener_dl_t *q,
srslte_wiener_dl_state_t *state,
cf_t *pilots,
float snr_lin) {
// there are pilot symbols (even) in this OFDM period (first symbol of the slot)
circshift_dim1(state->hls_fifo_2, SRSLTE_WIENER_DL_HLS_FIFO_SIZE, 1); // shift matrix rows down one position
memcpy(state->hls_fifo_2[0], pilots, NSAMPLES2NBYTES(q->nof_ref));
// Online training for pilot filtering
circshift_dim2(&state->timefifo, 1, SRSLTE_WIENER_DL_TIMEFIFO_SIZE, 1); // shift columns right one position
state->timefifo[0] = conjf(pilots[q->nof_ref / 2]); // train with center of subband frequency
circshift_dim1(state->cxfifo, SRSLTE_WIENER_DL_CXFIFO_SIZE, 1); // shift rows down one position
srslte_vec_sc_prod_ccc(state->timefifo, pilots[q->nof_ref / 2], state->cxfifo[0], SRSLTE_WIENER_DL_TIMEFIFO_SIZE);
// Calculate auto-correlation and normalize
matrix_acc_dim1_cc(state->cxfifo, q->tmp, SRSLTE_WIENER_DL_CXFIFO_SIZE, SRSLTE_WIENER_DL_TIMEFIFO_SIZE);
srslte_vec_sc_prod_cfc(q->tmp, 1.0f / SRSLTE_WIENER_DL_CXFIFO_SIZE, q->tmp, SRSLTE_WIENER_DL_TIMEFIFO_SIZE);
// Find index of half amplitude
uint32_t halfcx = vec_find_first_smaller_than_cf(q->tmp, cabsf(q->tmp[1]) * 0.5f, SRSLTE_WIENER_DL_TFIFO_SIZE, 2);
// Update internal states
state->sumlen = SRSLTE_MAX(1, floorf(halfcx / 8.0f * SRSLTE_MIN(2.0f, 1.0f + 1.0f / snr_lin)));
state->skip = SRSLTE_MAX(1, floorf(halfcx / 4.0f * SRSLTE_MIN(1, snr_lin / 16.0f)));
state->deltan = 0;
state->invtpilotoff = M_1_3;
}
static void srslte_wiener_dl_run_symbol_2_9(srslte_wiener_dl_t *q, srslte_wiener_dl_state_t *state) {
// here we only shift and feed TD interpolation fifo
circshift_dim1(state->tfifo, SRSLTE_WIENER_DL_TFIFO_SIZE, 1); // shift matrix columns right by one position
// Average Reference Signals
matrix_acc_dim1_cc(state->hls_fifo_2, q->tmp, SRSLTE_WIENER_DL_HLS_FIFO_SIZE, q->nof_ref); // Sum values
srslte_vec_sc_prod_cfc(q->tmp, 1.0f / state->sumlen, q->tmp, q->nof_ref); // Sacle sum
// Estimate channel based on the wiener matrix 2
estimate_wiener(q, q->wm2, q->tmp, state->tfifo[0]);
// Update internal states
state->deltan = 0.0f;
state->invtpilotoff = M_1_3;
}
static void srslte_wiener_dl_run_symbol_5_12(srslte_wiener_dl_t *q,
srslte_wiener_dl_state_t *state,
cf_t *pilots,
uint32_t shift) {
// there are pilot symbols (odd) in this OFDM period (fifth symbol of the slot)
circshift_dim1(state->hls_fifo_1, SRSLTE_WIENER_DL_HLS_FIFO_SIZE, 1); // shift matrix rows down one position
memcpy(state->hls_fifo_1[0], pilots, NSAMPLES2NBYTES(q->nof_ref));
circshift_dim1(state->tfifo, SRSLTE_WIENER_DL_TFIFO_SIZE, 1); // shift matrix columns right by one position
// Average Reference Signals
matrix_acc_dim1_cc(state->hls_fifo_1, q->tmp, SRSLTE_WIENER_DL_HLS_FIFO_SIZE, q->nof_ref); // Sum values
srslte_vec_sc_prod_cfc(q->tmp, 1.0f / state->sumlen, q->tmp, q->nof_ref); // Sacle sum
// Estimate channel based on the wiener matrix 1
estimate_wiener(q, q->wm1, q->tmp, state->tfifo[0]);
// Update internal states
state->deltan = 0.0f;
state->invtpilotoff = M_1_4;
state->cnt++;
// Online training of Wiener matrices (random sub-bands)
if (state->cnt == state->skip) {
state->cnt = 0; // Reset counter
uint32_t pos1, pos2, nsbb, pstart;
pos1 = (shift < 3) ? 0 : 3;
pos2 = (pos1 + 3) % 6;
// Choose randomly a pair of PRB and calculate the start reference signal
nsbb = srslte_random_uniform_int_dist(q->random, 0, q->nof_prb / 2);
if (nsbb == 0) {
pstart = 0;
} else if (nsbb >= (q->nof_prb / 2) - 1) {
pstart = q->nof_ref - SRSLTE_WIENER_DL_MIN_REF;
} else {
pstart = (SRSLTE_WIENER_DL_MIN_REF / 2) * nsbb - 1;
}
bzero(q->hlsv, NSAMPLES2NBYTES(SRSLTE_WIENER_DL_MIN_RE));
bzero(q->hlsv_sum, NSAMPLES2NBYTES(SRSLTE_WIENER_DL_MIN_RE));
for(uint32_t i = pos2, k = pstart; i < SRSLTE_WIENER_DL_MIN_RE; i += 6, k++) {
q->hlsv[i] = conjf(state->hls_fifo_2[1][k] + (state->hls_fifo_2[0][k] - state->hls_fifo_2[1][k]) * M_4_7);
}
for(uint32_t i = pos1, k = pstart; i < SRSLTE_WIENER_DL_MIN_RE; i += 6, k++) {
q->hlsv[i] = conjf(state->hls_fifo_1[1][k]);
}
for(uint32_t i = 0; i < SRSLTE_WIENER_DL_MIN_REF * 2; i++) {
srslte_vec_sc_prod_ccc(q->hlsv, conjf(q->hlsv[0]), q->tmp, SRSLTE_WIENER_DL_MIN_RE);
srslte_vec_sum_ccc(q->tmp, q->hlsv_sum, q->hlsv_sum, SRSLTE_WIENER_DL_MIN_RE);
}
}
}
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) {
int ret = SRSLTE_ERROR_INVALID_INPUTS;
if (q) {
// m is based on 0, increase one;
m++;
// Process symbol
switch (m) {
case 1:
case 8:
srslte_wiener_dl_run_symbol_1_8(q, q->state[tx][rx], pilots, snr_lin);
break;
case 2:
case 9:
srslte_wiener_dl_run_symbol_2_9(q, q->state[tx][rx]);
break;
case 5:
case 12:
srslte_wiener_dl_run_symbol_5_12(q, q->state[tx][rx], pilots, snr_lin);
break;
default:
perror("unhandled switch-case");
}
// Estimate
ret = SRSLTE_SUCCESS;
}
return ret;
}
void srslte_wiener_dl_free(srslte_wiener_dl_t *q) {
if (q) {
for(uint32_t tx = 0; tx < SRSLTE_MAX_PORTS; tx++) {
for(uint32_t rx = 0; rx < SRSLTE_MAX_PORTS; rx++) {
if (q->state[tx][rx]) {
srslte_wiener_dl_state_free(q->state[tx][rx]);
q->state[tx][rx] = NULL;
}
}
}
if (q->tmp) {
free(q->tmp);
}
if (q->random) {
srslte_random_free(q->random);
}
}
}
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