mirror of https://github.com/PentHertz/srsLTE.git
74 lines
2.2 KiB
C
74 lines
2.2 KiB
C
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/*
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* Copyright (c) 2013, Ismael Gomez-Miguelez <gomezi@tcd.ie>.
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* This file is part of OSLD-lib (http://https://github.com/ismagom/osld-lib)
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*
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* OSLD-lib 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 published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* OSLD-lib 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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* You should have received a copy of the GNU Lesser General Public License
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* along with OSLD-lib. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <strings.h>
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#include <stdlib.h>
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#include "lte/base.h"
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#include "utils/dft.h"
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#include "lte/fft.h"
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int lte_fft_init_(lte_fft_t *q, lte_cp_t cp_type, int symbol_sz, dft_dir_t dir) {
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if (dft_plan_c2c(symbol_sz, dir, &q->fft_plan)) {
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return -1;
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}
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q->fft_plan.options = DFT_DC_OFFSET | DFT_MIRROR_POS | DFT_NORMALIZE;
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q->nof_symbols = CP_NSYMB(cp_type);
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q->symbol_sz = symbol_sz;
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q->cp_type = cp_type;
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return 0;
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}
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void lte_fft_free_(lte_fft_t *q) {
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dft_plan_free(&q->fft_plan);
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bzero(q, sizeof(lte_fft_t));
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}
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int lte_fft_init(lte_fft_t *q, lte_cp_t cp_type, int symbol_sz) {
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return lte_fft_init_(q, cp_type, symbol_sz, FORWARD);
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}
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void lte_fft_free(lte_fft_t *q) {
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lte_fft_free_(q);
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}
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int lte_ifft_init(lte_fft_t *q, lte_cp_t cp_type, int symbol_sz) {
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return lte_fft_init_(q, cp_type, symbol_sz, BACKWARD);
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}
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void lte_ifft_free(lte_fft_t *q) {
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lte_fft_free_(q);
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}
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/* Transforms input samples into output OFDM symbols.
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* Performs FFT on a each symbol and removes CP.
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*/
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void lte_fft_run(lte_fft_t *q, cf_t *input, cf_t *output) {
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int i;
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for (i=0;i<q->nof_symbols;i++) {
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input += CP_ISNORM(q->cp_type)?CP_NORM(i, q->symbol_sz):CP_EXT(q->symbol_sz);
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dft_run_c2c(&q->fft_plan, input, output);
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input += q->symbol_sz;
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output += q->symbol_sz;
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}
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}
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/* Transforms input OFDM symbols into output samples.
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* Performs FFT on a each symbol and adds CP.
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*/
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void lte_ifft_run(lte_fft_t *q, cf_t *input, cf_t *output) {
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fprintf(stderr, "Error: Not implemented\n");
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}
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