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93 lines
2.4 KiB
C
93 lines
2.4 KiB
C
/**
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*
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* \section COPYRIGHT
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*
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* Copyright 2013-2014 The libLTE Developers. See the
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* COPYRIGHT file at the top-level directory of this distribution.
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*
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* \section LICENSE
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*
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* This file is part of the libLTE library.
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*
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* libLTE is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as
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* published by the Free Software Foundation, either version 3 of
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* the License, or (at your option) any later version.
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*
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* libLTE is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* A copy of the GNU Lesser General Public License can be found in
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* the LICENSE file in the top-level directory of this distribution
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* and at http://www.gnu.org/licenses/.
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*
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*/
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#include <strings.h>
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#include <stdlib.h>
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#include <math.h>
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#include "liblte/phy/utils/cexptab.h"
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#include "liblte/phy/sync/cfo.h"
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#include "liblte/phy/utils/vector.h"
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#include "liblte/phy/utils/debug.h"
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int cfo_init(cfo_t *h, uint32_t nsamples) {
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int ret = LIBLTE_ERROR;
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bzero(h, sizeof(cfo_t));
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if (cexptab_init(&h->tab, CFO_CEXPTAB_SIZE)) {
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goto clean;
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}
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h->cur_cexp = vec_malloc(sizeof(cf_t) * nsamples);
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if (!h->cur_cexp) {
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goto clean;
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}
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h->tol = CFO_TOLERANCE;
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h->last_freq = 0;
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h->nsamples = nsamples;
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cexptab_gen(&h->tab, h->cur_cexp, h->last_freq, h->nsamples);
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ret = LIBLTE_SUCCESS;
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clean:
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if (ret == LIBLTE_ERROR) {
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cfo_free(h);
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}
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return ret;
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}
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void cfo_free(cfo_t *h) {
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cexptab_free(&h->tab);
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if (h->cur_cexp) {
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free(h->cur_cexp);
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}
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bzero(h, sizeof(cf_t));
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}
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void cfo_set_tol(cfo_t *h, float tol) {
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h->tol = tol;
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}
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int cfo_realloc(cfo_t *h, uint32_t samples) {
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h->cur_cexp = realloc(h->cur_cexp, sizeof(cf_t) * samples);
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if (!h->cur_cexp) {
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perror("realloc");
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return LIBLTE_ERROR;
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}
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cexptab_gen(&h->tab, h->cur_cexp, h->last_freq, samples);
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h->nsamples = samples;
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return LIBLTE_SUCCESS;
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}
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void cfo_correct(cfo_t *h, cf_t *input, cf_t *output, float freq) {
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if (fabs(h->last_freq - freq) > h->tol) {
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h->last_freq = freq;
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cexptab_gen(&h->tab, h->cur_cexp, h->last_freq, h->nsamples);
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DEBUG("CFO generating new table for frequency %.4f\n", freq);
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}
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vec_prod_ccc(h->cur_cexp, input, output, h->nsamples);
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}
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