Common library for all Osmocom projects (libosmocore, libosmogsm, libosmovty, libosmogb, libosmosim, libosmousb, ...) https://osmocom.org/projects/libosmocore
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libosmocore/src/coding/gsm0503_interleaving.c

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/*
* (C) 2013 by Andreas Eversberg <jolly@eversberg.eu>
* (C) 2016 by Tom Tsou <tom.tsou@ettus.com>
*
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdint.h>
#include <string.h>
#include <osmocom/core/bits.h>
#include <osmocom/coding/gsm0503_tables.h>
#include <osmocom/coding/gsm0503_interleaving.h>
/*
* GSM xCCH interleaving and burst mapping
*
* Interleaving:
*
* Given 456 coded input bits, form 4 blocks of 114 bits:
*
* i(B, j) = c(n, k) k = 0, ..., 455
* n = 0, ..., N, N + 1, ...
* B = B_0 + 4n + (k mod 4)
* j = 2(49k mod 57) + ((k mod 8) div 4)
*
* Mapping on Burst:
*
* e(B, j) = i(B, j)
* e(B, 59 + j) = i(B, 57 + j) j = 0, ..., 56
* e(B, 57) = h_l(B)
* e(B, 58) = h_n(B)
*
* Where hl(B) and hn(B) are bits in burst B indicating flags.
*/
void gsm0503_xcch_deinterleave(sbit_t *cB, const sbit_t *iB)
{
int j, k, B;
for (k = 0; k < 456; k++) {
B = k & 3;
j = 2 * ((49 * k) % 57) + ((k & 7) >> 2);
cB[k] = iB[B * 114 + j];
}
}
void gsm0503_xcch_interleave(ubit_t *cB, ubit_t *iB)
{
int j, k, B;
for (k = 0; k < 456; k++) {
B = k & 3;
j = 2 * ((49 * k) % 57) + ((k & 7) >> 2);
iB[B * 114 + j] = cB[k];
}
}
void gsm0503_mcs1_dl_deinterleave(sbit_t *u, sbit_t *hc,
sbit_t *dc, const sbit_t *iB)
{
int k;
sbit_t c[452];
sbit_t cp[456];
gsm0503_xcch_deinterleave(cp, iB);
for (k = 0; k < 25; k++)
c[k] = cp[k];
for (k = 26; k < 82; k++)
c[k - 1] = cp[k];
for (k = 83; k < 139; k++)
c[k - 2] = cp[k];
for (k = 140; k < 424; k++)
c[k - 3] = cp[k];
for (k = 425; k < 456; k++)
c[k - 4] = cp[k];
if (u) {
for (k = 0; k < 12; k++)
u[k] = c[k];
}
if (hc) {
for (k = 12; k < 80; k++)
hc[k - 12] = c[k];
}
if (dc) {
for (k = 80; k < 452; k++)
dc[k - 80] = c[k];
}
}
void gsm0503_mcs1_dl_interleave(const ubit_t *up, const ubit_t *hc,
const ubit_t *dc, ubit_t *iB)
{
int k;
ubit_t c[452];
ubit_t cp[456];
for (k = 0; k < 12; k++)
c[k] = up[k];
for (k = 12; k < 80; k++)
c[k] = hc[k - 12];
for (k = 80; k < 452; k++)
c[k] = dc[k - 80];
for (k = 0; k < 25; k++)
cp[k] = c[k];
for (k = 26; k < 82; k++)
cp[k] = c[k - 1];
for (k = 83; k < 139; k++)
cp[k] = c[k - 2];
for (k = 140; k < 424; k++)
cp[k] = c[k - 3];
for (k = 425; k < 456; k++)
cp[k] = c[k - 4];
cp[25] = 0;
cp[82] = 0;
cp[139] = 0;
cp[424] = 0;
gsm0503_xcch_interleave(cp, iB);
}
void gsm0503_mcs1_ul_deinterleave(sbit_t *hc, sbit_t *dc, const sbit_t *iB)
{
int k;
sbit_t c[452];
sbit_t cp[456];
gsm0503_xcch_deinterleave(cp, iB);
for (k = 0; k < 25; k++)
c[k] = cp[k];
for (k = 26; k < 82; k++)
c[k - 1] = cp[k];
for (k = 83; k < 139; k++)
c[k - 2] = cp[k];
for (k = 140; k < 424; k++)
c[k - 3] = cp[k];
for (k = 425; k < 456; k++)
c[k - 4] = cp[k];
if (hc) {
for (k = 0; k < 80; k++)
hc[k] = c[k];
}
if (dc) {
for (k = 80; k < 452; k++)
dc[k - 80] = c[k];
}
}
void gsm0503_mcs1_ul_interleave(const ubit_t *hc, const ubit_t *dc, ubit_t *iB)
{
int k;
ubit_t c[452];
ubit_t cp[456];
for (k = 0; k < 80; k++)
c[k] = hc[k];
for (k = 80; k < 452; k++)
c[k] = dc[k - 80];
for (k = 0; k < 25; k++)
cp[k] = c[k];
for (k = 26; k < 82; k++)
cp[k] = c[k - 1];
for (k = 83; k < 139; k++)
cp[k] = c[k - 2];
for (k = 140; k < 424; k++)
cp[k] = c[k - 3];
for (k = 425; k < 456; k++)
cp[k] = c[k - 4];
cp[25] = 0;
cp[82] = 0;
cp[139] = 0;
cp[424] = 0;
gsm0503_xcch_interleave(cp, iB);
}
void gsm0503_mcs5_ul_interleave(const ubit_t *hc, const ubit_t *dc,
ubit_t *hi, ubit_t *di)
{
int j, k;
/* Header */
for (k = 0; k < 136; k++) {
j = 34 * (k % 4) + 2 * (11 * k % 17) + k % 8 / 4;
hi[j] = hc[k];
}
/* Data */
for (k = 0; k < 1248; k++) {
j = gsm0503_interleave_mcs5[k];
di[j] = dc[k];
}
}
void gsm0503_mcs5_ul_deinterleave(sbit_t *hc, sbit_t *dc,
const sbit_t *hi, const sbit_t *di)
{
int j, k;
/* Header */
if (hc) {
for (k = 0; k < 136; k++) {
j = 34 * (k % 4) + 2 * (11 * k % 17) + k % 8 / 4;
hc[k] = hi[j];
}
}
/* Data */
if (dc) {
for (k = 0; k < 1248; k++) {
j = gsm0503_interleave_mcs5[k];
dc[k] = di[j];
}
}
}
void gsm0503_mcs5_dl_interleave(const ubit_t *hc, const ubit_t *dc,
ubit_t *hi, ubit_t *di)
{
int j, k;
/* Header */
for (k = 0; k < 100; k++) {
j = 25 * (k % 4) + ((17 * k) % 25);
hi[j] = hc[k];
}
/* Data */
for (k = 0; k < 1248; k++) {
j = gsm0503_interleave_mcs5[k];
di[j] = dc[k];
}
}
void gsm0503_mcs5_dl_deinterleave(sbit_t *hc, sbit_t *dc,
const sbit_t *hi, const sbit_t *di)
{
int j, k;
/* Header */
if (hc) {
for (k = 0; k < 100; k++) {
j = 25 * (k % 4) + ((17 * k) % 25);
hc[k] = hi[j];
}
}
/* Data */
if (dc) {
for (k = 0; k < 1248; k++) {
j = gsm0503_interleave_mcs5[k];
dc[k] = di[j];
}
}
}
void gsm0503_mcs7_dl_interleave(const ubit_t *hc, const ubit_t *c1,
const ubit_t *c2, ubit_t *hi, ubit_t *di)
{
int j, k;
ubit_t dc[1224];
/* Header */
for (k = 0; k < 124; k++) {
j = 31 * (k % 4) + ((17 * k) % 31);
hi[j] = hc[k];
}
memcpy(&dc[0], c1, 612);
memcpy(&dc[612], c2, 612);
/* Data */
for (k = 0; k < 1224; k++) {
j = 306 * (k % 4) + 3 * (44 * k % 102 + k / 4 % 2) +
(k + 2 - k / 408) % 3;
di[j] = dc[k];
}
}
void gsm0503_mcs7_dl_deinterleave(sbit_t *hc, sbit_t *c1, sbit_t *c2,
const sbit_t *hi, const sbit_t *di)
{
int j, k;
ubit_t dc[1224];
/* Header */
if (hc) {
for (k = 0; k < 124; k++) {
j = 31 * (k % 4) + ((17 * k) % 31);
hc[k] = hi[j];
}
}
/* Data */
if (c1 && c2) {
for (k = 0; k < 1224; k++) {
j = 306 * (k % 4) + 3 * (44 * k % 102 + k / 4 % 2) +
(k + 2 - k / 408) % 3;
dc[k] = di[j];
}
memcpy(c1, &dc[0], 612);
memcpy(c2, &dc[612], 612);
}
}
void gsm0503_mcs7_ul_interleave(const ubit_t *hc, const ubit_t *c1,
const ubit_t *c2, ubit_t *hi, ubit_t *di)
{
int j, k;
ubit_t dc[1224];
/* Header */
for (k = 0; k < 160; k++) {
j = 40 * (k % 4) + 2 * (13 * (k / 8) % 20) + k % 8 / 4;
hi[j] = hc[k];
}
memcpy(&dc[0], c1, 612);
memcpy(&dc[612], c2, 612);
/* Data */
for (k = 0; k < 1224; k++) {
j = 306 * (k % 4) + 3 * (44 * k % 102 + k / 4 % 2) +
(k + 2 - k / 408) % 3;
di[j] = dc[k];
}
}
void gsm0503_mcs7_ul_deinterleave(sbit_t *hc, sbit_t *c1, sbit_t *c2,
const sbit_t *hi, const sbit_t *di)
{
int j, k;
ubit_t dc[1224];
/* Header */
if (hc) {
for (k = 0; k < 160; k++) {
j = 40 * (k % 4) + 2 * (13 * (k / 8) % 20) + k % 8 / 4;
hc[k] = hi[j];
}
}
/* Data */
if (c1 && c2) {
for (k = 0; k < 1224; k++) {
j = 306 * (k % 4) + 3 * (44 * k % 102 + k / 4 % 2) +
(k + 2 - k / 408) % 3;
dc[k] = di[j];
}
memcpy(c1, &dc[0], 612);
memcpy(c2, &dc[612], 612);
}
}
void gsm0503_mcs8_ul_interleave(const ubit_t *hc, const ubit_t *c1,
const ubit_t *c2, ubit_t *hi, ubit_t *di)
{
int j, k;
ubit_t dc[1224];
/* Header */
for (k = 0; k < 160; k++) {
j = 40 * (k % 4) + 2 * (13 * (k / 8) % 20) + k % 8 / 4;
hi[j] = hc[k];
}
memcpy(&dc[0], c1, 612);
memcpy(&dc[612], c2, 612);
/* Data */
for (k = 0; k < 1224; k++) {
j = 306 * (2 * (k / 612) + (k % 2)) +
3 * (74 * k % 102 + k / 2 % 2) + (k + 2 - k / 204) % 3;
di[j] = dc[k];
}
}
void gsm0503_mcs8_ul_deinterleave(sbit_t *hc, sbit_t *c1, sbit_t *c2,
const sbit_t *hi, const sbit_t *di)
{
int j, k;
ubit_t dc[1224];
/* Header */
if (hc) {
for (k = 0; k < 160; k++) {
j = 40 * (k % 4) + 2 * (13 * (k / 8) % 20) + k % 8 / 4;
hc[k] = hi[j];
}
}
/* Data */
if (c1 && c2) {
for (k = 0; k < 1224; k++) {
j = 306 * (2 * (k / 612) + (k % 2)) +
3 * (74 * k % 102 + k / 2 % 2) + (k + 2 - k / 204) % 3;
dc[k] = di[j];
}
memcpy(c1, &dc[0], 612);
memcpy(c2, &dc[612], 612);
}
}
void gsm0503_mcs8_dl_interleave(const ubit_t *hc, const ubit_t *c1,
const ubit_t *c2, ubit_t *hi, ubit_t *di)
{
int j, k;
ubit_t dc[1224];
/* Header */
for (k = 0; k < 124; k++) {
j = 31 * (k % 4) + ((17 * k) % 31);
hi[j] = hc[k];
}
memcpy(&dc[0], c1, 612);
memcpy(&dc[612], c2, 612);
/* Data */
for (k = 0; k < 1224; k++) {
j = 306 * (2 * (k / 612) + (k % 2)) +
3 * (74 * k % 102 + k / 2 % 2) + (k + 2 - k / 204) % 3;
di[j] = dc[k];
}
}
void gsm0503_mcs8_dl_deinterleave(sbit_t *hc, sbit_t *c1, sbit_t *c2,
const sbit_t *hi, const sbit_t *di)
{
int j, k;
ubit_t dc[1224];
/* Header */
if (hc) {
for (k = 0; k < 124; k++) {
j = 31 * (k % 4) + ((17 * k) % 31);
hc[k] = hi[j];
}
}
/* Data */
if (c1 && c2) {
for (k = 0; k < 1224; k++) {
j = 306 * (2 * (k / 612) + (k % 2)) +
3 * (74 * k % 102 + k / 2 % 2) + (k + 2 - k / 204) % 3;
dc[k] = di[j];
}
memcpy(c1, &dc[0], 612);
memcpy(c2, &dc[612], 612);
}
}
/*
* GSM TCH FR/EFR/AFS interleaving and burst mapping
*
* Interleaving:
*
* Given 456 coded input bits, form 8 blocks of 114 bits,
* where even bits of the first 4 blocks and odd bits of the last 4 blocks
* are used:
*
* i(B, j) = c(n, k) k = 0, ..., 455
* n = 0, ..., N, N + 1, ...
* B = B_0 + 4n + (k mod 8)
* j = 2(49k mod 57) + ((k mod 8) div 4)
*
* Mapping on Burst:
*
* e(B, j) = i(B, j)
* e(B, 59 + j) = i(B, 57 + j) j = 0, ..., 56
* e(B, 57) = h_l(B)
* e(B, 58) = h_n(B)
*
* Where hl(B) and hn(B) are bits in burst B indicating flags.
*/
void gsm0503_tch_fr_deinterleave(sbit_t *cB, sbit_t *iB)
{
int j, k, B;
for (k = 0; k < 456; k++) {
B = k & 7;
j = 2 * ((49 * k) % 57) + ((k & 7) >> 2);
cB[k] = iB[B * 114 + j];
}
}
void gsm0503_tch_fr_interleave(ubit_t *cB, ubit_t *iB)
{
int j, k, B;
for (k = 0; k < 456; k++) {
B = k & 7;
j = 2 * ((49 * k) % 57) + ((k & 7) >> 2);
iB[B * 114 + j] = cB[k];
}
}
/*
* GSM TCH HR/AHS interleaving and burst mapping
*
* Interleaving:
*
* Given 288 coded input bits, form 4 blocks of 114 bits,
* where even bits of the first 2 blocks and odd bits of the last 2 blocks
* are used:
*
* i(B, j) = c(n, k) k = 0, ..., 227
* n = 0, ..., N, N + 1, ...
* B = B_0 + 2n + b
* j, b = table[k];
*
* Mapping on Burst:
*
* e(B, j) = i(B, j)
* e(B, 59 + j) = i(B, 57 + j) j = 0, ..., 56
* e(B, 57) = h_l(B)
* e(B, 58) = h_n(B)
*
* Where hl(B) and hn(B) are bits in burst B indicating flags.
*/
void gsm0503_tch_hr_deinterleave(sbit_t *cB, sbit_t *iB)
{
int j, k, B;
for (k = 0; k < 228; k++) {
B = gsm0503_tch_hr_interleaving[k][1];
j = gsm0503_tch_hr_interleaving[k][0];
cB[k] = iB[B * 114 + j];
}
}
void gsm0503_tch_hr_interleave(ubit_t *cB, ubit_t *iB)
{
int j, k, B;
for (k = 0; k < 228; k++) {
B = gsm0503_tch_hr_interleaving[k][1];
j = gsm0503_tch_hr_interleaving[k][0];
iB[B * 114 + j] = cB[k];
}
}