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.
109 lines
2.3 KiB
C
109 lines
2.3 KiB
C
/**
|
|
*
|
|
* \section COPYRIGHT
|
|
*
|
|
* Copyright 2013-2014 The libLTE Developers. See the
|
|
* COPYRIGHT file at the top-level directory of this distribution.
|
|
*
|
|
* \section LICENSE
|
|
*
|
|
* This file is part of the libLTE library.
|
|
*
|
|
* libLTE is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU Lesser General Public License as
|
|
* published by the Free Software Foundation, either version 3 of
|
|
* the License, or (at your option) any later version.
|
|
*
|
|
* libLTE 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 Lesser General Public License for more details.
|
|
*
|
|
* A copy of the GNU Lesser 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 "liblte/phy/common/sequence.h"
|
|
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <strings.h>
|
|
#include <assert.h>
|
|
|
|
#define Nc 1600
|
|
|
|
|
|
/*
|
|
* Pseudo Random Sequence generation.
|
|
* It follows the 3GPP Release 8 (LTE) 36.211
|
|
* Section 7.2
|
|
*/
|
|
void generate_prs_c(sequence_t *q, unsigned int seed) {
|
|
int n;
|
|
unsigned int *x1;
|
|
unsigned int *x2;
|
|
|
|
x1 = calloc(Nc + q->len + 31, sizeof(unsigned int));
|
|
if (!x1) {
|
|
perror("calloc");
|
|
return;
|
|
}
|
|
x2 = calloc(Nc + q->len + 31, sizeof(unsigned int));
|
|
if (!x2) {
|
|
free(x1);
|
|
perror("calloc");
|
|
return;
|
|
}
|
|
|
|
for (n = 0; n < 31; n++) {
|
|
x2[n] = (seed >> n) & 0x1;
|
|
}
|
|
x1[0] = 1;
|
|
|
|
for (n = 0; n < Nc + q->len; n++) {
|
|
x1[n + 31] = (x1[n + 3] + x1[n]) & 0x1;
|
|
x2[n + 31] = (x2[n + 3] + x2[n + 2] + +x2[n+1] + x2[n]) & 0x1;
|
|
}
|
|
|
|
for (n = 0; n < q->len; n++) {
|
|
q->c[n] = (x1[n + Nc] + x2[n + Nc]) & 0x1;
|
|
}
|
|
|
|
free(x1);
|
|
free(x2);
|
|
}
|
|
|
|
int sequence_LTEPRS(sequence_t *q, int len, int seed) {
|
|
if (sequence_init(q, len)) {
|
|
return -1;
|
|
}
|
|
q->len = len;
|
|
generate_prs_c(q, seed);
|
|
return 0;
|
|
}
|
|
|
|
int sequence_init(sequence_t *q, int len) {
|
|
if (q->c && (q->len != len)) {
|
|
free(q->c);
|
|
}
|
|
if (!q->c) {
|
|
q->c = malloc(len * sizeof(char));
|
|
if (!q->c) {
|
|
return -1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void sequence_free(sequence_t *q) {
|
|
if (q->c) {
|
|
free(q->c);
|
|
}
|
|
bzero(q, sizeof(sequence_t));
|
|
}
|
|
|
|
|