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srsLTE/lib/src/phy/phch/uci.c

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/**
* Copyright 2013-2022 Software Radio Systems Limited
*
* This file is part of srsRAN.
*
* srsRAN 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.
*
* srsRAN 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 <assert.h>
#include <math.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include "srsran/phy/common/phy_common.h"
#include "srsran/phy/fec/block/block.h"
#include "srsran/phy/fec/convolutional/convcoder.h"
#include "srsran/phy/fec/convolutional/rm_conv.h"
#include "srsran/phy/fec/crc.h"
#include "srsran/phy/phch/uci.h"
#include "srsran/phy/utils/bit.h"
#include "srsran/phy/utils/debug.h"
#include "srsran/phy/utils/vector.h"
/* Table 5.2.3.3-1: Basis sequences for (20, A) code */
static uint8_t M_basis_seq_pucch[20][13] = {
{1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0}, {1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0},
{1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1}, {1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 1, 1},
{1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1}, {1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1},
{1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1}, {1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1},
{1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1}, {1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1},
{1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1}, {1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1},
{1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1}, {1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1},
{1, 0, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1}, {1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1},
{1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1}, {1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1},
{1, 1, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0}, {1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0},
};
void srsran_uci_cqi_pucch_init(srsran_uci_cqi_pucch_t* q)
{
uint8_t word[16];
uint32_t nwords = 1 << SRSRAN_UCI_MAX_CQI_LEN_PUCCH;
q->cqi_table = srsran_vec_malloc(nwords * sizeof(int8_t*));
q->cqi_table_s = srsran_vec_malloc(nwords * sizeof(int16_t*));
for (uint32_t w = 0; w < nwords; w++) {
q->cqi_table[w] = srsran_vec_malloc(SRSRAN_UCI_CQI_CODED_PUCCH_B * sizeof(int8_t));
q->cqi_table_s[w] = srsran_vec_malloc(SRSRAN_UCI_CQI_CODED_PUCCH_B * sizeof(int16_t));
uint8_t* ptr = word;
srsran_bit_unpack(w, &ptr, SRSRAN_UCI_MAX_CQI_LEN_PUCCH);
srsran_uci_encode_cqi_pucch(word, SRSRAN_UCI_MAX_CQI_LEN_PUCCH, q->cqi_table[w]);
for (int j = 0; j < SRSRAN_UCI_CQI_CODED_PUCCH_B; j++) {
q->cqi_table_s[w][j] = (int16_t)(2 * q->cqi_table[w][j] - 1);
}
}
}
void srsran_uci_cqi_pucch_free(srsran_uci_cqi_pucch_t* q)
{
uint32_t nwords = 1 << SRSRAN_UCI_MAX_CQI_LEN_PUCCH;
for (uint32_t w = 0; w < nwords; w++) {
if (q->cqi_table[w]) {
free(q->cqi_table[w]);
}
if (q->cqi_table_s[w]) {
free(q->cqi_table_s[w]);
}
}
free(q->cqi_table);
free(q->cqi_table_s);
}
/* Encode UCI CQI/PMI as described in 5.2.3.3 of 36.212
*/
int srsran_uci_encode_cqi_pucch(uint8_t* cqi_data, uint32_t cqi_len, uint8_t b_bits[SRSRAN_UCI_CQI_CODED_PUCCH_B])
{
if (cqi_len <= SRSRAN_UCI_MAX_CQI_LEN_PUCCH) {
for (uint32_t i = 0; i < SRSRAN_UCI_CQI_CODED_PUCCH_B; i++) {
uint64_t x = 0;
for (uint32_t n = 0; n < cqi_len; n++) {
x += cqi_data[n] * M_basis_seq_pucch[i][n];
}
b_bits[i] = (uint8_t)(x % 2);
}
return SRSRAN_SUCCESS;
} else {
return SRSRAN_ERROR_INVALID_INPUTS;
}
}
int srsran_uci_encode_cqi_pucch_from_table(srsran_uci_cqi_pucch_t* q,
uint8_t* cqi_data,
uint32_t cqi_len,
uint8_t b_bits[SRSRAN_UCI_CQI_CODED_PUCCH_B])
{
if (cqi_len <= SRSRAN_UCI_MAX_CQI_LEN_PUCCH) {
bzero(&cqi_data[cqi_len], SRSRAN_UCI_MAX_CQI_LEN_PUCCH - cqi_len);
uint8_t* ptr = cqi_data;
uint32_t packed = srsran_bit_pack(&ptr, SRSRAN_UCI_MAX_CQI_LEN_PUCCH);
memcpy(b_bits, q->cqi_table[packed], SRSRAN_UCI_CQI_CODED_PUCCH_B);
return SRSRAN_SUCCESS;
} else {
return SRSRAN_ERROR_INVALID_INPUTS;
}
}
/* Decode UCI CQI/PMI over PUCCH
*/
int16_t srsran_uci_decode_cqi_pucch(srsran_uci_cqi_pucch_t* q,
int16_t b_bits[SRSRAN_CQI_MAX_BITS],
uint8_t* cqi_data,
uint32_t cqi_len)
{
if (q != NULL && cqi_len < SRSRAN_UCI_MAX_CQI_LEN_PUCCH && b_bits != NULL && cqi_data != NULL) {
uint32_t max_w = 0;
int32_t max_corr = INT32_MIN;
uint32_t nwords = 1 << SRSRAN_UCI_MAX_CQI_LEN_PUCCH;
for (uint32_t w = 0; w < nwords; w += 1 << (SRSRAN_UCI_MAX_CQI_LEN_PUCCH - cqi_len)) {
// Calculate correlation with pregenerated word and select maximum
int32_t corr = srsran_vec_dot_prod_sss(q->cqi_table_s[w], b_bits, SRSRAN_UCI_CQI_CODED_PUCCH_B);
if (corr > max_corr) {
max_corr = corr;
max_w = w;
}
}
// Convert word to bits again
uint8_t* ptr = cqi_data;
srsran_bit_unpack(max_w, &ptr, SRSRAN_UCI_MAX_CQI_LEN_PUCCH);
INFO("Decoded CQI: w=%d, corr=%d", max_w, max_corr);
return max_corr;
} else {
return SRSRAN_ERROR_INVALID_INPUTS;
}
}
int srsran_uci_cqi_init(srsran_uci_cqi_pusch_t* q)
{
if (srsran_crc_init(&q->crc, SRSRAN_LTE_CRC8, 8)) {
return SRSRAN_ERROR;
}
int poly[3] = {0x6D, 0x4F, 0x57};
if (srsran_viterbi_init(&q->viterbi, SRSRAN_VITERBI_37, poly, SRSRAN_UCI_MAX_CQI_LEN_PUSCH, true)) {
return SRSRAN_ERROR;
}
return SRSRAN_SUCCESS;
}
void srsran_uci_cqi_free(srsran_uci_cqi_pusch_t* q)
{
srsran_viterbi_free(&q->viterbi);
}
static uint32_t Q_prime_cqi(srsran_pusch_cfg_t* cfg, uint32_t O, float beta, uint32_t Q_prime_ri)
{
uint32_t K = cfg->K_segm;
uint32_t Q_prime = 0;
uint32_t L = (O < 11) ? 0 : 8;
uint32_t x = 999999;
if (K > 0) {
x = (uint32_t)ceilf((float)(O + L) * cfg->grant.L_prb * SRSRAN_NRE * cfg->grant.nof_symb * beta / K);
}
Q_prime = SRSRAN_MIN(x, cfg->grant.L_prb * SRSRAN_NRE * cfg->grant.nof_symb - Q_prime_ri);
return Q_prime;
}
uint32_t srsran_qprime_cqi_ext(uint32_t L_prb, uint32_t nof_symbols, uint32_t tbs, float beta)
{
srsran_pusch_cfg_t cfg = {};
cfg.grant.L_prb = L_prb;
cfg.grant.nof_symb = nof_symbols;
cfg.K_segm = tbs;
// O is the number of CQI + CRC len (8). See 5.2.2.6
return Q_prime_cqi(&cfg, SRSRAN_UCI_CQI_CODED_PUCCH_B + 8, beta, 0);
}
/* Encode UCI CQI/PMI for payloads equal or lower to 11 bits (Sec 5.2.2.6.4)
*/
int encode_cqi_short(srsran_uci_cqi_pusch_t* q, uint8_t* data, uint32_t nof_bits, uint8_t* q_bits, uint32_t Q)
{
if (nof_bits <= SRSRAN_FEC_BLOCK_MAX_NOF_BITS && nof_bits > 0 && q != NULL && data != NULL && q_bits != NULL) {
srsran_block_encode(data, nof_bits, q_bits, Q);
return SRSRAN_SUCCESS;
}
return SRSRAN_ERROR_INVALID_INPUTS;
}
// For decoding the block-encoded CQI we use ML decoding
int decode_cqi_short(srsran_uci_cqi_pusch_t* q, int16_t* q_bits, uint32_t Q, uint8_t* data, uint32_t nof_bits)
{
if (nof_bits <= SRSRAN_FEC_BLOCK_MAX_NOF_BITS && nof_bits > 0 && q != NULL && data != NULL && q_bits != NULL) {
int32_t max_corr = srsran_block_decode_i16(q_bits, Q, data, nof_bits);
INFO("Decoded CQI: corr=%d", max_corr);
return SRSRAN_SUCCESS;
} else {
return SRSRAN_ERROR_INVALID_INPUTS;
}
}
/* Encode UCI CQI/PMI for payloads greater than 11 bits (go through CRC, conv coder and rate match)
*/
int encode_cqi_long(srsran_uci_cqi_pusch_t* q, uint8_t* data, uint32_t nof_bits, uint8_t* q_bits, uint32_t Q)
{
srsran_convcoder_t encoder;
if (nof_bits + 8 < SRSRAN_UCI_MAX_CQI_LEN_PUSCH && q != NULL && data != NULL && q_bits != NULL) {
int poly[3] = {0x6D, 0x4F, 0x57};
encoder.K = 7;
encoder.R = 3;
encoder.tail_biting = true;
memcpy(encoder.poly, poly, 3 * sizeof(int));
memcpy(q->tmp_cqi, data, sizeof(uint8_t) * nof_bits);
srsran_crc_attach(&q->crc, q->tmp_cqi, nof_bits);
DEBUG("cqi_crc_tx=");
if (SRSRAN_VERBOSE_ISDEBUG()) {
srsran_vec_fprint_b(stdout, q->tmp_cqi, nof_bits + 8);
}
srsran_convcoder_encode(&encoder, q->tmp_cqi, q->encoded_cqi, nof_bits + 8);
DEBUG("cconv_tx=");
if (SRSRAN_VERBOSE_ISDEBUG()) {
srsran_vec_fprint_b(stdout, q->encoded_cqi, 3 * (nof_bits + 8));
}
srsran_rm_conv_tx(q->encoded_cqi, 3 * (nof_bits + 8), q_bits, Q);
return SRSRAN_SUCCESS;
} else {
return SRSRAN_ERROR_INVALID_INPUTS;
}
}
int decode_cqi_long(srsran_uci_cqi_pusch_t* q, int16_t* q_bits, uint32_t Q, uint8_t* data, uint32_t nof_bits)
{
int ret = SRSRAN_ERROR_INVALID_INPUTS;
if (nof_bits + 8 < SRSRAN_UCI_MAX_CQI_LEN_PUSCH && q != NULL && data != NULL && q_bits != NULL) {
srsran_rm_conv_rx_s(q_bits, Q, q->encoded_cqi_s, 3 * (nof_bits + 8));
DEBUG("cconv_rx=");
if (SRSRAN_VERBOSE_ISDEBUG()) {
srsran_vec_fprint_s(stdout, q->encoded_cqi_s, 3 * (nof_bits + 8));
}
srsran_viterbi_decode_s(&q->viterbi, q->encoded_cqi_s, q->tmp_cqi, nof_bits + 8);
DEBUG("cqi_crc_rx=");
if (SRSRAN_VERBOSE_ISDEBUG()) {
srsran_vec_fprint_b(stdout, q->tmp_cqi, nof_bits + 8);
}
ret = srsran_crc_checksum(&q->crc, q->tmp_cqi, nof_bits + 8);
if (ret == 0) {
memcpy(data, q->tmp_cqi, nof_bits * sizeof(uint8_t));
ret = 1;
} else {
ret = 0;
}
}
return ret;
}
/* Encode UCI CQI/PMI
*/
int srsran_uci_decode_cqi_pusch(srsran_uci_cqi_pusch_t* q,
srsran_pusch_cfg_t* cfg,
int16_t* q_bits,
float beta,
uint32_t Q_prime_ri,
uint32_t cqi_len,
uint8_t* cqi_data,
bool* cqi_ack)
{
if (beta < 0) {
ERROR("Error beta is reserved");
return -1;
}
uint32_t Q_prime = Q_prime_cqi(cfg, cqi_len, beta, Q_prime_ri);
uint32_t Qm = srsran_mod_bits_x_symbol(cfg->grant.tb.mod);
int ret = SRSRAN_ERROR;
if (cqi_len <= 11) {
ret = decode_cqi_short(q, q_bits, Q_prime * Qm, cqi_data, cqi_len);
if (cqi_ack) {
*cqi_ack = true;
}
} else {
ret = decode_cqi_long(q, q_bits, Q_prime * Qm, cqi_data, cqi_len);
if (ret == 1) {
if (cqi_ack) {
*cqi_ack = true;
}
ret = 0;
} else if (ret == 0) {
if (cqi_ack) {
*cqi_ack = false;
}
}
}
if (ret) {
return ret;
} else {
return (int)Q_prime;
}
}
/* Encode UCI CQI/PMI as described in 5.2.2.6 of 36.212
*/
int srsran_uci_encode_cqi_pusch(srsran_uci_cqi_pusch_t* q,
srsran_pusch_cfg_t* cfg,
uint8_t* cqi_data,
uint32_t cqi_len,
float beta,
uint32_t Q_prime_ri,
uint8_t* q_bits)
{
if (beta < 0) {
ERROR("Error beta is reserved");
return -1;
}
uint32_t Q_prime = Q_prime_cqi(cfg, cqi_len, beta, Q_prime_ri);
uint32_t Qm = srsran_mod_bits_x_symbol(cfg->grant.tb.mod);
int ret = SRSRAN_ERROR;
if (cqi_len <= 11) {
ret = encode_cqi_short(q, cqi_data, cqi_len, q_bits, Q_prime * Qm);
} else {
ret = encode_cqi_long(q, cqi_data, cqi_len, q_bits, Q_prime * Qm);
}
if (ret) {
return ret;
} else {
return (int)Q_prime;
}
}
/* Generates UCI-ACK bits and computes position in q bits */
static int uci_ulsch_interleave_ack_gen(uint32_t ack_q_bit_idx,
uint32_t Qm,
uint32_t H_prime_total,
uint32_t N_pusch_symbs,
srsran_uci_bit_t* ack_bits)
{
const uint32_t ack_column_set_norm[4] = {2, 3, 8, 9};
const uint32_t ack_column_set_ext[4] = {1, 2, 6, 7};
if (H_prime_total / N_pusch_symbs >= 1 + ack_q_bit_idx / 4) {
uint32_t row = H_prime_total / N_pusch_symbs - 1 - ack_q_bit_idx / 4;
uint32_t colidx = (3 * ack_q_bit_idx) % 4;
uint32_t col = N_pusch_symbs > 10 ? ack_column_set_norm[colidx] : ack_column_set_ext[colidx];
for (uint32_t k = 0; k < Qm; k++) {
ack_bits[k].position = row * Qm + (H_prime_total / N_pusch_symbs) * col * Qm + k;
}
return SRSRAN_SUCCESS;
} else {
ERROR("Error interleaving UCI-ACK bit idx %d for H_prime_total=%d and N_pusch_symbs=%d",
ack_q_bit_idx,
H_prime_total,
N_pusch_symbs);
return SRSRAN_ERROR;
}
}
/* Inserts UCI-RI bits into the correct positions in the g buffer before interleaving */
static int uci_ulsch_interleave_ri_gen(uint32_t ri_q_bit_idx,
uint32_t Qm,
uint32_t H_prime_total,
uint32_t N_pusch_symbs,
srsran_uci_bit_t* ri_bits)
{
static uint32_t ri_column_set_norm[4] = {1, 4, 7, 10};
static uint32_t ri_column_set_ext[4] = {0, 3, 5, 8};
if (H_prime_total / N_pusch_symbs >= 1 + ri_q_bit_idx / 4) {
uint32_t row = H_prime_total / N_pusch_symbs - 1 - ri_q_bit_idx / 4;
uint32_t colidx = (3 * ri_q_bit_idx) % 4;
uint32_t col = N_pusch_symbs > 10 ? ri_column_set_norm[colidx] : ri_column_set_ext[colidx];
for (uint32_t k = 0; k < Qm; k++) {
ri_bits[k].position = row * Qm + (H_prime_total / N_pusch_symbs) * col * Qm + k;
}
return SRSRAN_SUCCESS;
} else {
ERROR("Error interleaving UCI-RI bit idx %d for H_prime_total=%d and N_pusch_symbs=%d",
ri_q_bit_idx,
H_prime_total,
N_pusch_symbs);
return SRSRAN_ERROR;
}
}
static uint32_t Q_prime_ri_ack(srsran_pusch_cfg_t* cfg, uint32_t O, uint32_t O_cqi, float beta)
{
if (beta < 0) {
ERROR("Error beta is reserved");
return -1;
}
uint32_t K = cfg->K_segm;
// If not carrying UL-SCH, get Q_prime according to 5.2.4.1
if (K == 0) {
if (O_cqi <= 11) {
K = O_cqi;
} else {
K = O_cqi + 8;
}
}
if (K == 0) {
ERROR("K is zero!");
return 0;
}
uint32_t x = (uint32_t)ceilf((float)O * cfg->grant.L_prb * SRSRAN_NRE * cfg->grant.nof_symb * beta / K);
uint32_t Q_prime = SRSRAN_MIN(x, 4 * cfg->grant.L_prb * SRSRAN_NRE);
return Q_prime;
}
uint32_t srsran_qprime_ack_ext(uint32_t L_prb, uint32_t nof_symbols, uint32_t tbs, uint32_t nof_ack, float beta)
{
srsran_pusch_cfg_t cfg = {};
cfg.grant.L_prb = L_prb;
cfg.grant.nof_symb = nof_symbols;
cfg.K_segm = tbs;
return Q_prime_ri_ack(&cfg, nof_ack, 0, beta);
}
static uint32_t encode_ri_ack(const uint8_t data[2], uint32_t O_ack, uint8_t Qm, srsran_uci_bit_t* q_encoded_bits)
{
uint32_t i = 0;
if (O_ack == 1) {
q_encoded_bits[i++].type = data[0] ? UCI_BIT_1 : UCI_BIT_0;
q_encoded_bits[i++].type = UCI_BIT_REPETITION;
while (i < Qm) {
q_encoded_bits[i++].type = UCI_BIT_PLACEHOLDER;
}
} else if (O_ack == 2) {
q_encoded_bits[i++].type = data[0] ? UCI_BIT_1 : UCI_BIT_0;
q_encoded_bits[i++].type = data[1] ? UCI_BIT_1 : UCI_BIT_0;
while (i < Qm) {
q_encoded_bits[i++].type = UCI_BIT_PLACEHOLDER;
}
q_encoded_bits[i++].type = (data[0] ^ data[1]) ? UCI_BIT_1 : UCI_BIT_0;
q_encoded_bits[i++].type = data[0] ? UCI_BIT_1 : UCI_BIT_0;
while (i < Qm * 2) {
q_encoded_bits[i++].type = UCI_BIT_PLACEHOLDER;
}
q_encoded_bits[i++].type = data[1] ? UCI_BIT_1 : UCI_BIT_0;
q_encoded_bits[i++].type = (data[0] ^ data[1]) ? UCI_BIT_1 : UCI_BIT_0;
while (i < Qm * 3) {
q_encoded_bits[i++].type = UCI_BIT_PLACEHOLDER;
}
}
return i;
}
static uint32_t
encode_ack_long(const uint8_t* data, uint32_t O_ack, uint8_t Q_m, uint32_t Q_prime, srsran_uci_bit_t* q_encoded_bits)
{
uint32_t Q_ack = Q_m * Q_prime;
if (O_ack > SRSRAN_UCI_MAX_ACK_BITS) {
ERROR("Error encoding long ACK bits: O_ack can't be higher than %d", SRSRAN_UCI_MAX_ACK_BITS);
return 0;
}
// Encoded bits
uint8_t q[SRSRAN_FEC_BLOCK_SIZE] = {};
// Encode
srsran_block_encode(data, O_ack, q, SRSRAN_FEC_BLOCK_SIZE);
// Convert to UCI bits
for (uint32_t i = 0; i < Q_ack; i++) {
q_encoded_bits[i].type = q[i % SRSRAN_FEC_BLOCK_SIZE] ? UCI_BIT_1 : UCI_BIT_0;
}
return Q_ack;
}
static int32_t decode_ri_ack_1bit(const int16_t* q_bits, const uint8_t* c_seq, uint8_t data[1])
{
int32_t sum = (int32_t)(q_bits[0] + q_bits[1]);
if (data) {
data[0] = (sum > 0) ? 1 : 0;
}
return abs(sum);
}
static int32_t decode_ri_ack_2bits(const int16_t* llr, uint32_t Qm, uint8_t data[2])
{
uint32_t p0 = Qm * 0 + 0;
uint32_t p1 = Qm * 0 + 1;
uint32_t p2 = Qm * 1 + 0;
uint32_t p3 = Qm * 1 + 1;
uint32_t p4 = Qm * 2 + 0;
uint32_t p5 = Qm * 2 + 1;
int16_t sum1 = llr[p0] + llr[p3];
int16_t sum2 = llr[p1] + llr[p4];
int16_t sum3 = llr[p2] + llr[p5];
data[0] = (sum1 > 0) ? 1 : 0;
data[1] = (sum2 > 0) ? 1 : 0;
bool parity_check = (sum3 > 0) == (data[0] ^ data[1]);
// Return 0 if parity check is not valid
return (parity_check ? (abs(sum1) + abs(sum2) + abs(sum3)) : 0);
}
// Table 5.2.2.6-A
const static uint8_t w_scram[4][4] = {{1, 1, 1, 1}, {1, 0, 1, 0}, {1, 1, 0, 0}, {1, 0, 0, 1}};
static void uci_ack_scramble_tdd(srsran_uci_bit_t* q, uint32_t O_ack, uint32_t Q_ack, uint32_t N_bundle)
{
if (N_bundle == 0) {
return;
}
uint32_t wi = (N_bundle - 1) % 4;
uint32_t m = O_ack == 1 ? 1 : 3;
srsran_uci_bit_type_t q_m1 = q[0].type;
uint32_t k = 0;
for (uint32_t i = 0; i < Q_ack; i++) {
switch (q[i].type) {
case UCI_BIT_REPETITION:
// A repetition bit always comes after a 1 or 0 so we can do i-1
if (i > 0) {
q[i].type = ((q_m1 == UCI_BIT_1 ? 1 : 0) + w_scram[wi][k / m]) % 2;
}
k = (k + 1) % (4 * m);
break;
case UCI_BIT_PLACEHOLDER:
// do not change
break;
default:
q_m1 = q[i].type;
q[i].type = ((q[i].type == UCI_BIT_1 ? 1 : 0) + w_scram[wi][k / m]) % 2;
k = (k + 1) % (4 * m);
break;
}
}
}
/* Encode UCI ACK/RI bits as described in 5.2.2.6 of 36.212
* Currently only supporting 1-bit RI
*/
int srsran_uci_encode_ack_ri(srsran_pusch_cfg_t* cfg,
uint8_t* data,
uint32_t O_ack,
uint32_t O_cqi,
float beta,
uint32_t H_prime_total,
bool input_is_ri,
uint32_t N_bundle,
srsran_uci_bit_t* bits)
{
if (beta < 0) {
ERROR("Error beta is reserved");
return -1;
}
uint32_t Q_prime = Q_prime_ri_ack(cfg, O_ack, O_cqi, beta);
uint32_t Q_ack = 0;
uint32_t Qm = srsran_mod_bits_x_symbol(cfg->grant.tb.mod);
if (O_ack < 3) {
uint32_t enc_len = encode_ri_ack(data, O_ack, Qm, bits);
// Repeat bits Q_prime times, remainder bits will be ignored later
while (Q_ack < Q_prime * Qm) {
for (uint32_t j = 0; j < enc_len; j++) {
bits[Q_ack++].type = bits[j].type;
}
}
} else {
Q_ack = encode_ack_long(data, O_ack, Qm, Q_prime, bits);
}
// Generate interleaver positions
if (Q_ack > 0) {
for (uint32_t i = 0; i < Q_prime; i++) {
if (input_is_ri) {
uci_ulsch_interleave_ri_gen(i, Qm, H_prime_total, cfg->grant.nof_symb, &bits[Qm * i]);
} else {
uci_ulsch_interleave_ack_gen(i, Qm, H_prime_total, cfg->grant.nof_symb, &bits[Qm * i]);
}
}
// TDD-bundling scrambling
if (!input_is_ri && N_bundle && O_ack > 0) {
uci_ack_scramble_tdd(bits, O_ack, Q_prime * Qm, N_bundle);
}
}
return (int)Q_prime;
}
/* Decode UCI ACK/RI bits as described in 5.2.2.6 of 36.212
* Currently only supporting 1-bit RI
*/
int srsran_uci_decode_ack_ri(srsran_pusch_cfg_t* cfg,
int16_t* q_bits,
uint8_t* c_seq,
float beta,
uint32_t H_prime_total,
uint32_t O_cqi,
srsran_uci_bit_t* ack_ri_bits,
uint8_t* data,
bool* valid,
uint32_t nof_bits,
bool is_ri)
{
if (beta < 0) {
ERROR("Error beta (%f) is reserved", beta);
return SRSRAN_ERROR;
}
uint32_t Qprime = Q_prime_ri_ack(cfg, nof_bits, O_cqi, beta);
uint32_t Qm = srsran_mod_bits_x_symbol(cfg->grant.tb.mod);
int16_t llr_acc[32] = {}; ///< LLR accumulator
uint32_t nof_acc = (nof_bits == 1) ? Qm
: (nof_bits == 2) ? Qm * 3
: SRSRAN_FEC_BLOCK_SIZE; ///< Number of required LLR
uint32_t count_acc = 0; ///< LLR counter
for (uint32_t i = 0; i < Qprime; i++) {
if (is_ri) {
uci_ulsch_interleave_ri_gen(i, Qm, H_prime_total, cfg->grant.nof_symb, &ack_ri_bits[count_acc]);
} else {
uci_ulsch_interleave_ack_gen(i, Qm, H_prime_total, cfg->grant.nof_symb, &ack_ri_bits[count_acc]);
}
/// Extract and accumulate LLR
for (uint32_t j = 0; j < Qm; j++, count_acc++) {
// Calculate circular LLR index
uint32_t acc_idx = count_acc % nof_acc;
uint32_t pos = ack_ri_bits[count_acc].position;
int16_t q = q_bits[pos];
// Remove scrambling of repeated bits
if (nof_bits == 1) {
if (acc_idx == 1 && pos > 0) {
q = (c_seq[pos] == c_seq[pos - 1]) ? +q : -q;
}
}
// Accumulate LLR
llr_acc[acc_idx] += q;
/// Limit accumulator boundaries
llr_acc[acc_idx] = SRSRAN_MIN(llr_acc[acc_idx], INT16_MAX / 2);
llr_acc[acc_idx] = SRSRAN_MAX(llr_acc[acc_idx], -INT16_MAX / 2);
}
}
/// Decode UCI HARQ/ACK bits as described in 5.2.2.6 of 36.212
int32_t thr = (count_acc * ((Qm < 4) ? 100 : (Qm < 6) ? 200 : (Qm < 8) ? 700 : 1000)) / Qm;
int32_t corr = 0;
switch (nof_bits) {
case 1:
corr = decode_ri_ack_1bit(llr_acc, c_seq, data);
break;
case 2:
corr = decode_ri_ack_2bits(llr_acc, Qm, data);
break;
default:
// For more than 2 bits...
corr = srsran_block_decode_i16(llr_acc, SRSRAN_FEC_BLOCK_SIZE, data, nof_bits);
}
if (valid) {
*valid = corr > thr;
}
return (int)Qprime;
}
uint32_t srsran_uci_cfg_total_ack(const srsran_uci_cfg_t* uci_cfg)
{
uint32_t nof_ack = 0;
for (uint32_t i = 0; i < SRSRAN_MAX_CARRIERS; i++) {
nof_ack += uci_cfg->ack[i].nof_acks;
}
return nof_ack;
}
void srsran_uci_data_reset(srsran_uci_data_t* uci_data)
{
bzero(uci_data, sizeof(srsran_uci_data_t));
/* Set all ACKs to DTX */
memset(uci_data->value.ack.ack_value, 2, SRSRAN_UCI_MAX_ACK_BITS);
}
int srsran_uci_data_info(srsran_uci_cfg_t* uci_cfg, srsran_uci_value_t* uci_data, char* str, uint32_t str_len)
{
int n = 0;
if (uci_cfg->is_scheduling_request_tti) {
n = srsran_print_check(str, str_len, n, ", sr=%s", uci_data->scheduling_request ? "yes" : "no");
}
uint32_t nof_acks = srsran_uci_cfg_total_ack(uci_cfg);
if (nof_acks) {
n = srsran_print_check(str, str_len, n, ", ack=");
if (uci_data->ack.valid) {
for (uint32_t i = 0; i < nof_acks; i++) {
n = srsran_print_check(str, str_len, n, "%d", uci_data->ack.ack_value[i]);
}
if (uci_cfg->ack[0].N_bundle) {
n = srsran_print_check(str, str_len, n, ", n_bundle=%d", uci_cfg->ack[0].N_bundle);
}
} else {
n = srsran_print_check(str, str_len, n, "invalid");
}
}
if (uci_cfg->cqi.ri_len) {
n = srsran_print_check(str, str_len, n, ", ri=%d", uci_data->ri);
}
if (uci_cfg->cqi.data_enable) {
char cqi_str[SRSRAN_CQI_STR_MAX_CHAR] = "";
srsran_cqi_value_tostring(&uci_cfg->cqi, &uci_data->cqi, cqi_str, SRSRAN_CQI_STR_MAX_CHAR);
n = srsran_print_check(str, str_len, n, "%s (cc=%d)", cqi_str, uci_cfg->cqi.scell_index);
}
return n;
}
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