int srslte_layermap_multiplex(cf_t *d[SRSLTE_MAX_CODEWORDS], cf_t *x[SRSLTE_MAX_LAYERS], int nof_cw, int nof_layers,
int nof_symbols[SRSLTE_MAX_CODEWORDS]) {
if (nof_cw == nof_layers) {
for (int i = 0; i < nof_cw; i++) {
srs_vec_cf_cpy(d[i], x[i], (uint32_t) nof_symbols[0]);
}
return nof_symbols[0];
} else if (nof_cw == 1) {
return srslte_layermap_diversity(d[0], x, nof_layers, nof_symbols[0]);
} else {
int n[2];
n[0] = nof_layers / nof_cw;
n[1] = nof_layers - n[0];
if (nof_symbols[0] / n[0] == nof_symbols[1] / n[1]) {
srslte_layermap_diversity(d[0], x, n[0], nof_symbols[0]);
srslte_layermap_diversity(d[1], &x[n[0]], n[1], nof_symbols[1]);
return nof_symbols[0] / n[0];
} else {
ERROR("Number of symbols in codewords 0 and 1 is not consistent (%d, %d)\n", nof_symbols[0], nof_symbols[1]);
return -1;
}
}
return 0;
}
/** Encodes CFI and maps symbols to the slot
*/
int srslte_pcfich_encode(srslte_pcfich_t *q, uint32_t cfi, cf_t *slot_symbols[SRSLTE_MAX_PORTS],
uint32_t subframe) {
int i;
if (q != NULL &&
cfi < 3 &&
slot_symbols != NULL &&
subframe < SRSLTE_NSUBFRAMES_X_FRAME)
{
/* Set pointers for layermapping & precoding */
cf_t *x[SRSLTE_MAX_LAYERS];
cf_t *symbols_precoding[SRSLTE_MAX_PORTS];
/* number of layers equals number of ports */
for (i = 0; i < q->cell.nof_ports; i++) {
x[i] = q->x[i];
}
for (i = 0; i < SRSLTE_MAX_PORTS; i++) {
symbols_precoding[i] = q->symbols[i];
}
/* pack CFI */
srslte_pcfich_cfi_encode(cfi, q->data);
/* scramble for slot sequence nslot */
srslte_scrambling_b(&q->seq[subframe], q->data);
srslte_mod_modulate(&q->mod, q->data, q->d, PCFICH_CFI_LEN);
/* layer mapping & precoding */
if (q->cell.nof_ports > 1) {
srslte_layermap_diversity(q->d, x, q->cell.nof_ports, q->nof_symbols);
srslte_precoding_diversity(x, symbols_precoding, q->cell.nof_ports,
q->nof_symbols / q->cell.nof_ports);
} else {
memcpy(q->symbols[0], q->d, q->nof_symbols * sizeof(cf_t));
}
/* mapping to resource elements */
for (i = 0; i < q->cell.nof_ports; i++) {
if (srslte_regs_pcfich_put(q->regs, q->symbols[i], slot_symbols[i]) < 0) {
fprintf(stderr, "Error putting PCHICH resource elements\n");
return SRSLTE_ERROR;
}
}
return SRSLTE_SUCCESS;
} else {
return SRSLTE_ERROR_INVALID_INPUTS;
}
}
/* Layer mapping generates the vector of layer-mapped symbols "x" based on the vector of data symbols "d"
* Based on 36.211 6.3.3
* Returns the number of symbols per layer (M_symb^layer in the specs)
*/
int srslte_layermap_type(cf_t* d[SRSLTE_MAX_CODEWORDS],
cf_t* x[SRSLTE_MAX_LAYERS],
int nof_cw,
int nof_layers,
int nof_symbols[SRSLTE_MAX_CODEWORDS],
srslte_tx_scheme_t type)
{
if (nof_cw > SRSLTE_MAX_CODEWORDS) {
ERROR("Maximum number of codewords is %d (nof_cw=%d)\n", SRSLTE_MAX_CODEWORDS, nof_cw);
return -1;
}
if (nof_layers > SRSLTE_MAX_LAYERS) {
ERROR("Maximum number of layers is %d (nof_layers=%d)\n", SRSLTE_MAX_LAYERS, nof_layers);
return -1;
}
if (nof_layers < nof_cw) {
ERROR("Number of codewords must be lower or equal than number of layers\n");
return -1;
}
switch(type) {
case SRSLTE_TXSCHEME_PORT0:
if (nof_cw == 1 && nof_layers == 1) {
return srslte_layermap_single(d[0], x[0], nof_symbols[0]);
} else {
ERROR("Number of codewords and layers must be 1 for transmission on single antenna ports\n");
return -1;
}
break;
case SRSLTE_TXSCHEME_DIVERSITY:
if (nof_cw == 1) {
if (nof_layers == 2 || nof_layers == 4) {
return srslte_layermap_diversity(d[0], x, nof_layers, nof_symbols[0]);
} else {
ERROR("Number of layers must be 2 or 4 for transmit diversity\n");
return -1;
}
} else {
ERROR("Number of codewords must be 1 for transmit diversity\n");
return -1;
}
break;
case SRSLTE_TXSCHEME_SPATIALMUX:
case SRSLTE_TXSCHEME_CDD:
return srslte_layermap_multiplex(d, x, nof_cw, nof_layers, nof_symbols);
break;
}
return 0;
}
/** Converts the PDSCH data bits to symbols mapped to the slot ready for transmission
*/
int srslte_pdsch_encode_rnti(srslte_pdsch_t *q,
srslte_pdsch_cfg_t *cfg, srslte_softbuffer_tx_t *softbuffer,
uint8_t *data, uint16_t rnti, cf_t *sf_symbols[SRSLTE_MAX_PORTS])
{
int i;
/* Set pointers for layermapping & precoding */
cf_t *x[SRSLTE_MAX_LAYERS];
int ret = SRSLTE_ERROR_INVALID_INPUTS;
if (q != NULL &&
data != NULL &&
cfg != NULL)
{
for (i=0; i<q->cell.nof_ports; i++) {
if (sf_symbols[i] == NULL) {
return SRSLTE_ERROR_INVALID_INPUTS;
}
}
if (cfg->grant.mcs.tbs == 0) {
return SRSLTE_ERROR_INVALID_INPUTS;
}
if (cfg->nbits.nof_re > q->max_re) {
fprintf(stderr,
"Error too many RE per subframe (%d). PDSCH configured for %d RE (%d PRB)\n",
cfg->nbits.nof_re, q->max_re, q->cell.nof_prb);
return SRSLTE_ERROR_INVALID_INPUTS;
}
INFO("Encoding PDSCH SF: %d, Mod %s, NofBits: %d, NofSymbols: %d, NofBitsE: %d, rv_idx: %d\n",
cfg->sf_idx, srslte_mod_string(cfg->grant.mcs.mod), cfg->grant.mcs.tbs,
cfg->nbits.nof_re, cfg->nbits.nof_bits, cfg->rv);
/* number of layers equals number of ports */
for (i = 0; i < q->cell.nof_ports; i++) {
x[i] = q->x[i];
}
memset(&x[q->cell.nof_ports], 0, sizeof(cf_t*) * (SRSLTE_MAX_LAYERS - q->cell.nof_ports));
if (srslte_dlsch_encode(&q->dl_sch, cfg, softbuffer, data, q->e)) {
fprintf(stderr, "Error encoding TB\n");
return SRSLTE_ERROR;
}
if (rnti != q->rnti) {
srslte_sequence_t seq;
if (srslte_sequence_pdsch(&seq, rnti, 0, 2 * cfg->sf_idx, q->cell.id, cfg->nbits.nof_bits)) {
return SRSLTE_ERROR;
}
srslte_scrambling_bytes_offset(&seq, (uint8_t*) q->e, 0, cfg->nbits.nof_bits);
srslte_sequence_free(&seq);
} else {
srslte_scrambling_bytes_offset(&q->seq[cfg->sf_idx], (uint8_t*) q->e, 0, cfg->nbits.nof_bits);
}
srslte_mod_modulate_bytes(&q->mod[cfg->grant.mcs.mod], (uint8_t*) q->e, q->d, cfg->nbits.nof_bits);
/* TODO: only diversity supported */
if (q->cell.nof_ports > 1) {
srslte_layermap_diversity(q->d, x, q->cell.nof_ports, cfg->nbits.nof_re);
srslte_precoding_diversity(&q->precoding, x, q->symbols, q->cell.nof_ports,
cfg->nbits.nof_re / q->cell.nof_ports);
} else {
memcpy(q->symbols[0], q->d, cfg->nbits.nof_re * sizeof(cf_t));
}
/* mapping to resource elements */
for (i = 0; i < q->cell.nof_ports; i++) {
srslte_pdsch_put(q, q->symbols[i], sf_symbols[i], &cfg->grant, cfg->nbits.lstart, cfg->sf_idx);
}
ret = SRSLTE_SUCCESS;
}
return ret;
}
/** Encodes ACK/NACK bits, modulates and inserts into resource.
* The parameter ack is an array of srslte_phich_ngroups() pointers to buffers of nof_sequences uint8_ts
*/
int srslte_phich_encode(srslte_phich_t *q, uint8_t ack, uint32_t ngroup, uint32_t nseq, uint32_t subframe,
cf_t *slot_symbols[SRSLTE_MAX_PORTS]) {
int i;
if (q == NULL || slot_symbols == NULL) {
return SRSLTE_ERROR_INVALID_INPUTS;
}
if (subframe >= SRSLTE_NSUBFRAMES_X_FRAME) {
fprintf(stderr, "Invalid nslot %d\n", subframe);
return SRSLTE_ERROR_INVALID_INPUTS;
}
if (SRSLTE_CP_ISEXT(q->cell.cp)) {
if (nseq >= SRSLTE_PHICH_EXT_NSEQUENCES) {
fprintf(stderr, "Invalid nseq %d\n", nseq);
return SRSLTE_ERROR_INVALID_INPUTS;
}
} else {
if (nseq >= SRSLTE_PHICH_NORM_NSEQUENCES) {
fprintf(stderr, "Invalid nseq %d\n", nseq);
return SRSLTE_ERROR_INVALID_INPUTS;
}
}
if (ngroup >= srslte_regs_phich_ngroups(q->regs)) {
fprintf(stderr, "Invalid ngroup %d\n", ngroup);
return SRSLTE_ERROR_INVALID_INPUTS;
}
/* Set pointers for layermapping & precoding */
cf_t *x[SRSLTE_MAX_LAYERS];
cf_t *symbols_precoding[SRSLTE_MAX_PORTS];
/* number of layers equals number of ports */
for (i = 0; i < q->cell.nof_ports; i++) {
x[i] = q->x[i];
}
for (i = 0; i < SRSLTE_MAX_PORTS; i++) {
symbols_precoding[i] = q->symbols[i];
}
/* encode ACK/NACK bit */
srslte_phich_ack_encode(ack, q->data);
srslte_mod_modulate(&q->mod, q->data, q->z, SRSLTE_PHICH_NBITS);
DEBUG("data: ", 0);
if (SRSLTE_VERBOSE_ISDEBUG())
srslte_vec_fprint_c(stdout, q->z, SRSLTE_PHICH_NBITS);
/* Spread with w */
if (SRSLTE_CP_ISEXT(q->cell.cp)) {
for (i = 0; i < SRSLTE_PHICH_EXT_MSYMB; i++) {
q->d[i] = w_ext[nseq][i % SRSLTE_PHICH_EXT_NSF]
* q->z[i / SRSLTE_PHICH_EXT_NSF];
}
} else {
for (i = 0; i < SRSLTE_PHICH_NORM_MSYMB; i++) {
q->d[i] = w_normal[nseq][i % SRSLTE_PHICH_NORM_NSF]
* q->z[i / SRSLTE_PHICH_NORM_NSF];
}
}
DEBUG("d: ", 0);
if (SRSLTE_VERBOSE_ISDEBUG())
srslte_vec_fprint_c(stdout, q->d, SRSLTE_PHICH_EXT_MSYMB);
srslte_scrambling_c(&q->seq[subframe], q->d);
/* align to REG */
if (SRSLTE_CP_ISEXT(q->cell.cp)) {
if (ngroup % 2) {
for (i = 0; i < SRSLTE_PHICH_EXT_MSYMB / 2; i++) {
q->d0[4 * i + 0] = 0;
q->d0[4 * i + 1] = 0;
q->d0[4 * i + 2] = q->d[2 * i];
q->d0[4 * i + 3] = q->d[2 * i + 1];
}
} else {
for (i = 0; i < SRSLTE_PHICH_EXT_MSYMB / 2; i++) {
q->d0[4 * i + 0] = q->d[2 * i];
q->d0[4 * i + 1] = q->d[2 * i + 1];
q->d0[4 * i + 2] = 0;
q->d0[4 * i + 3] = 0;
}
}
} else {
memcpy(q->d0, q->d, SRSLTE_PHICH_MAX_NSYMB * sizeof(cf_t));
}
DEBUG("d0: ", 0);
if (SRSLTE_VERBOSE_ISDEBUG())
srslte_vec_fprint_c(stdout, q->d0, SRSLTE_PHICH_MAX_NSYMB);
/* layer mapping & precoding */
if (q->cell.nof_ports > 1) {
srslte_layermap_diversity(q->d0, x, q->cell.nof_ports, SRSLTE_PHICH_MAX_NSYMB);
srslte_precoding_diversity(&q->precoding, x, symbols_precoding, q->cell.nof_ports,
SRSLTE_PHICH_MAX_NSYMB / q->cell.nof_ports);
/**FIXME: According to 6.9.2, Precoding for 4 tx ports is different! */
} else {
memcpy(q->symbols[0], q->d0, SRSLTE_PHICH_MAX_NSYMB * sizeof(cf_t));
}
/* mapping to resource elements */
for (i = 0; i < q->cell.nof_ports; i++) {
if (srslte_regs_phich_add(q->regs, q->symbols[i], ngroup, slot_symbols[i])
< 0) {
fprintf(stderr, "Error putting PCHICH resource elements\n");
return SRSLTE_ERROR;
}
}
return SRSLTE_SUCCESS;
}
