/** Converts the MIB message to symbols mapped to SLOT #1 ready for transmission
*/
void pbch_encode(pbch_t *q, pbch_mib_t *mib,
cf_t *slot1_symbols[MAX_PORTS_CTRL], int nof_ports) {
int i;
int nof_bits = 2 * q->nof_symbols;
assert(nof_ports <= MAX_PORTS_CTRL);
/* Set pointers for layermapping & precoding */
cf_t *x[MAX_LAYERS];
/* number of layers equals number of ports */
for (i = 0; i < nof_ports; i++) {
x[i] = q->pbch_x[i];
}
memset(&x[nof_ports], 0, sizeof(cf_t*) * (MAX_LAYERS - nof_ports));
if (q->frame_idx == 0) {
/* pack MIB */
pbch_mib_pack(mib, q->data);
/* encode & modulate */
crc_attach(&q->crc, q->data, 24);
crc_set_mask(q->data, nof_ports);
convcoder_encode(&q->encoder, q->data, q->data_enc, 40);
rm_conv_tx(q->data_enc, 120, q->pbch_rm_b, 4 * nof_bits);
}
scrambling_b_offset(&q->seq_pbch, &q->pbch_rm_b[q->frame_idx * nof_bits],
q->frame_idx * nof_bits, nof_bits);
mod_modulate(&q->mod, &q->pbch_rm_b[q->frame_idx * nof_bits], q->pbch_d,
nof_bits);
/* layer mapping & precoding */
if (nof_ports > 1) {
layermap_diversity(q->pbch_d, x, nof_ports, q->nof_symbols);
precoding_diversity(x, q->pbch_symbols, nof_ports,
q->nof_symbols / nof_ports);
} else {
memcpy(q->pbch_symbols[0], q->pbch_d, q->nof_symbols * sizeof(cf_t));
}
/* mapping to resource elements */
for (i = 0; i < nof_ports; i++) {
pbch_put(q->pbch_symbols[i], slot1_symbols[i], q->nof_prb, q->cp,
q->cell_id);
}
q->frame_idx++;
if (q->frame_idx == 4) {
q->frame_idx = 0;
}
}
/* 36.211 v10.3.0 Section 6.3.4 */
int precoding_type(cf_t *x[MAX_LAYERS], cf_t *y[MAX_PORTS], int nof_layers,
int nof_ports, int nof_symbols, lte_mimo_type_t type) {
if (nof_ports > MAX_PORTS) {
fprintf(stderr, "Maximum number of ports is %d (nof_ports=%d)\n", MAX_PORTS,
nof_ports);
return -1;
}
if (nof_layers > MAX_LAYERS) {
fprintf(stderr, "Maximum number of layers is %d (nof_layers=%d)\n",
MAX_LAYERS, nof_layers);
return -1;
}
switch (type) {
case SINGLE_ANTENNA:
if (nof_ports == 1 && nof_layers == 1) {
return precoding_single(x[0], y[0], nof_symbols);
} else {
fprintf(stderr,
"Number of ports and layers must be 1 for transmission on single antenna ports\n");
return -1;
}
break;
case TX_DIVERSITY:
if (nof_ports == nof_layers) {
return precoding_diversity(x, y, nof_ports, nof_symbols);
} else {
fprintf(stderr,
"Error number of layers must equal number of ports in transmit diversity\n");
return -1;
}
case SPATIAL_MULTIPLEX:
fprintf(stderr, "Spatial multiplexing not supported\n");
return -1;
}
return 0;
}
/** Converts the MIB message to symbols mapped to SLOT #1 ready for transmission
*/
int pbch_encode(pbch_t *q, pbch_mib_t *mib, cf_t *slot1_symbols[MAX_PORTS]) {
int i;
int nof_bits;
cf_t *x[MAX_LAYERS];
if (q != NULL &&
mib != NULL)
{
for (i=0;i<q->cell.nof_ports;i++) {
if (slot1_symbols[i] == NULL) {
return LIBLTE_ERROR_INVALID_INPUTS;
}
}
/* Set pointers for layermapping & precoding */
nof_bits = 2 * q->nof_symbols;
/* number of layers equals number of ports */
for (i = 0; i < q->cell.nof_ports; i++) {
x[i] = q->pbch_x[i];
}
memset(&x[q->cell.nof_ports], 0, sizeof(cf_t*) * (MAX_LAYERS - q->cell.nof_ports));
if (q->frame_idx == 0) {
/* pack MIB */
pbch_mib_pack(mib, q->data);
/* encode & modulate */
crc_attach(&q->crc, q->data, 24);
crc_set_mask(q->data, q->cell.nof_ports);
convcoder_encode(&q->encoder, q->data, q->data_enc, 40);
rm_conv_tx(q->data_enc, 120, q->pbch_rm_b, 4 * nof_bits);
}
scrambling_b_offset(&q->seq_pbch, &q->pbch_rm_b[q->frame_idx * nof_bits],
q->frame_idx * nof_bits, nof_bits);
mod_modulate(&q->mod, &q->pbch_rm_b[q->frame_idx * nof_bits], q->pbch_d,
nof_bits);
/* layer mapping & precoding */
if (q->cell.nof_ports > 1) {
layermap_diversity(q->pbch_d, x, q->cell.nof_ports, q->nof_symbols);
precoding_diversity(x, q->pbch_symbols, q->cell.nof_ports,
q->nof_symbols / q->cell.nof_ports);
} else {
memcpy(q->pbch_symbols[0], q->pbch_d, q->nof_symbols * sizeof(cf_t));
}
/* mapping to resource elements */
for (i = 0; i < q->cell.nof_ports; i++) {
pbch_put(q->pbch_symbols[i], slot1_symbols[i], q->cell);
}
q->frame_idx++;
if (q->frame_idx == 4) {
q->frame_idx = 0;
}
return LIBLTE_SUCCESS;
} else {
return LIBLTE_ERROR_INVALID_INPUTS;
}
}