// Blind search for SI/P/RA-RNTI
static int find_dl_dci_type_siprarnti(srslte_ue_dl_t* q,
srslte_dl_sf_cfg_t* sf,
srslte_ue_dl_cfg_t* cfg,
uint16_t rnti,
srslte_dci_msg_t dci_msg[SRSLTE_MAX_DCI_MSG])
{
int ret = 0;
srslte_dci_cfg_t* dci_cfg = &cfg->dci_cfg;
// Configure and run DCI blind search
dci_blind_search_t search_space;
search_space.nof_locations = srslte_pdcch_common_locations(&q->pdcch, search_space.loc, MAX_CANDIDATES_COM, sf->cfi);
INFO("Searching SI/P/RA-RNTI in %d common locations, %d formats, tti=%d, cfi=%d, rnti=0x%x\n",
search_space.nof_locations,
nof_common_formats,
sf->tti,
sf->cfi,
rnti);
// Search for RNTI only if there is room for the common search space
if (search_space.nof_locations > 0) {
for (uint32_t f = 0; f < nof_common_formats; f++) {
search_space.format = common_formats[f];
if ((ret = dci_blind_search(q, sf, rnti, &search_space, dci_cfg, dci_msg))) {
return ret;
}
}
}
return SRSLTE_SUCCESS;
}
// Blind search for C-RNTI
static int find_dl_dci_type_crnti(srslte_ue_dl_t* q,
srslte_dl_sf_cfg_t* sf,
srslte_ue_dl_cfg_t* cfg,
uint16_t rnti,
srslte_dci_msg_t dci_msg[SRSLTE_MAX_DCI_MSG])
{
int ret = SRSLTE_SUCCESS;
dci_blind_search_t search_space;
dci_blind_search_t* current_ss = &search_space;
uint32_t sf_idx = sf->tti % 10;
uint32_t cfi = sf->cfi;
srslte_dci_cfg_t* dci_cfg = &cfg->dci_cfg;
// Search UE-specific search space
if (q->pregen_rnti == rnti) {
current_ss = &q->current_ss_ue[MI_IDX(sf_idx)][cfi - 1][sf_idx];
} else {
// If locations are not pre-generated, generate them now
current_ss->nof_locations = srslte_pdcch_ue_locations(&q->pdcch, sf, current_ss->loc, MAX_CANDIDATES_UE, rnti);
}
if (cfg->cfg.tm > SRSLTE_TM8) {
ERROR("Searching DL CRNTI: Invalid TM=%d\n", cfg->cfg.tm + 1);
}
for (int f = 0; f < 2; f++) {
srslte_dci_format_t format = ue_dci_formats[cfg->cfg.tm][f];
INFO("Searching DL C-RNTI %s in %d ue locations\n", srslte_dci_format_string(format), current_ss->nof_locations);
current_ss->format = format;
if ((ret = dci_blind_search(q, sf, rnti, current_ss, dci_cfg, dci_msg))) {
return ret;
}
}
// Search Format 1A in the Common SS also
if (q->pregen_rnti == rnti) {
current_ss = &q->current_ss_common[MI_IDX(sf_idx)][cfi - 1];
} else {
// If locations are not pre-generated, generate them now
current_ss->nof_locations = srslte_pdcch_common_locations(&q->pdcch, current_ss->loc, MAX_CANDIDATES_COM, cfi);
}
// Search for RNTI only if there is room for the common search space
if (current_ss->nof_locations > 0) {
current_ss->format = SRSLTE_DCI_FORMAT1A;
INFO("Searching DL C-RNTI in %d ue locations, format 1A\n", current_ss->nof_locations);
return dci_blind_search(q, sf, rnti, current_ss, dci_cfg, dci_msg);
}
return SRSLTE_SUCCESS;
}
/* Precalculate the PDSCH scramble sequences for a given RNTI. This function takes a while
* to execute, so shall be called once the final C-RNTI has been allocated for the session.
* For the connection procedure, use srslte_pusch_encode_rnti() or srslte_pusch_decode_rnti() functions
*/
void srslte_ue_dl_set_rnti(srslte_ue_dl_t *q, uint16_t rnti) {
srslte_pdsch_set_rnti(&q->pdsch, rnti);
// Compute UE-specific and Common search space for this RNTI
for (int cfi=0;cfi<3;cfi++) {
for (int sf_idx=0;sf_idx<10;sf_idx++) {
q->current_ss_ue[cfi][sf_idx].nof_locations = srslte_pdcch_ue_locations(&q->pdcch, q->current_ss_ue[cfi][sf_idx].loc, MAX_CANDIDATES_UE, sf_idx, cfi+1, rnti);
}
q->current_ss_common[cfi].nof_locations = srslte_pdcch_common_locations(&q->pdcch, q->current_ss_common[cfi].loc, MAX_CANDIDATES_COM, cfi+1);
}
q->current_rnti = rnti;
}
int srslte_ue_dl_find_dl_dci_type(srslte_ue_dl_t *q, srslte_dci_msg_t *dci_msg, uint32_t cfi, uint32_t sf_idx,
uint16_t rnti, srslte_rnti_type_t rnti_type)
{
srslte_dci_location_t locations[MAX_CANDIDATES];
uint32_t nof_locations;
uint32_t nof_formats;
srslte_dci_format_t *formats = NULL;
/* Generate PDCCH candidates */
if (rnti_type == SRSLTE_RNTI_SI || rnti_type == SRSLTE_RNTI_PCH || rnti_type == SRSLTE_RNTI_RAR) {
nof_locations = srslte_pdcch_common_locations(&q->pdcch, locations, MAX_CANDIDATES, q->cfi);
formats = common_formats;
nof_formats = nof_common_formats;
} else {
nof_locations = srslte_pdcch_ue_locations(&q->pdcch, locations, MAX_CANDIDATES, sf_idx, q->cfi, rnti);
formats = ue_formats;
nof_formats = nof_ue_formats;
}
uint16_t crc_rem = 0;
for (int f=0;f<nof_formats && crc_rem != rnti;f++) {
for (int i=0;i<nof_locations && crc_rem != rnti;i++) {
DEBUG("Trying format %s (nbits=%d), location L=%d, ncce=%d\n", srslte_dci_format_string(formats[f]),
srslte_dci_format_sizeof_lut(formats[f], q->cell.nof_prb), locations[i].L, locations[i].ncce);
q->last_n_cce = locations[i].ncce;
if (srslte_pdcch_decode_msg(&q->pdcch, dci_msg, &locations[i], formats[f], &crc_rem)) {
fprintf(stderr, "Error decoding DCI msg\n");
return SRSLTE_ERROR;
}
if (crc_rem == rnti) {
INFO("Found DCI nCCE: %d, L: %d, n_bits=%d\n", locations[i].ncce, locations[i].L, srslte_dci_format_sizeof_lut(formats[f], q->cell.nof_prb));
memcpy(&q->last_location, &locations[i], sizeof(srslte_dci_location_t));
}
if (crc_rem == rnti && formats[f] == SRSLTE_DCI_FORMAT1A && dci_msg->data[0] != 1) {
/* Save Format 0 msg. Recovered next call to srslte_ue_dl_find_ul_dci() */
q->pending_ul_dci_rnti = crc_rem;
memcpy(&q->pending_ul_dci_msg, dci_msg, sizeof(srslte_dci_msg_t));
crc_rem = 0;
}
DEBUG("Decoded DCI message RNTI: 0x%x\n", crc_rem);
}
}
if (crc_rem == rnti) {
return 1;
} else {
INFO("Couldn't find any DCI for RNTI=0x%x\n", rnti);
return 0;
}
}
// Blind search for C-RNTI
static int find_dl_dci_type_crnti(srslte_ue_dl_t *q, uint32_t tm, uint32_t cfi,
uint32_t sf_idx, uint16_t rnti, srslte_dci_msg_t *dci_msg) {
int ret = SRSLTE_SUCCESS;
dci_blind_search_t search_space;
dci_blind_search_t *current_ss = &search_space;
if (cfi < 1 || cfi > 3) {
ERROR("CFI must be 1 ≤ cfi ≤ 3 (cfi=%d)", cfi);
return SRSLTE_ERROR;
}
// Search UE-specific search space
if (q->current_rnti == rnti) {
current_ss = &q->current_ss_ue[cfi-1][sf_idx];
} else {
// If locations are not pre-generated, generate them now
current_ss->nof_locations = srslte_pdcch_ue_locations(&q->pdcch, current_ss->loc, MAX_CANDIDATES_UE, sf_idx, cfi, rnti);
}
for (int f = 0; f < 2; f++) {
srslte_dci_format_t format = ue_dci_formats[tm][f];
INFO("Searching DL C-RNTI %s in %d ue locations\n", srslte_dci_format_string(format),
current_ss->nof_locations);
current_ss->format = format;
if ((ret = dci_blind_search(q, current_ss, rnti, cfi, dci_msg))) {
return ret;
}
}
// Search Format 1A in the Common SS also
if (q->current_rnti == rnti) {
current_ss = &q->current_ss_common[cfi-1];
} else {
// If locations are not pre-generated, generate them now
current_ss->nof_locations = srslte_pdcch_common_locations(&q->pdcch, current_ss->loc, MAX_CANDIDATES_COM, cfi);
}
// Search for RNTI only if there is room for the common search space
if (current_ss->nof_locations > 0) {
current_ss->format = SRSLTE_DCI_FORMAT1A;
INFO("Searching DL C-RNTI in %d ue locations, format 1A\n", current_ss->nof_locations);
return dci_blind_search(q, current_ss, rnti, cfi, dci_msg);
}
return SRSLTE_SUCCESS;
}
// Blind search for SI/P/RA-RNTI
static int find_dl_dci_type_siprarnti(srslte_ue_dl_t *q, uint32_t cfi, uint16_t rnti, srslte_dci_msg_t *dci_msg)
{
int ret = 0;
// Configure and run DCI blind search
dci_blind_search_t search_space;
search_space.nof_locations = srslte_pdcch_common_locations(&q->pdcch, search_space.loc, MAX_CANDIDATES_COM, cfi);
INFO("Searching SI/P/RA-RNTI in %d common locations, %d formats\n", search_space.nof_locations, nof_common_formats);
// Search for RNTI only if there is room for the common search space
if (search_space.nof_locations > 0) {
for (int f=0;f<nof_common_formats;f++) {
search_space.format = common_formats[f];
if ((ret = dci_blind_search(q, &search_space, rnti, cfi, dci_msg))) {
return ret;
}
}
}
return SRSLTE_SUCCESS;
}
int srslte_ue_dl_find_dl_dci(srslte_ue_dl_t *q, srslte_dci_msg_t *dci_msg, uint32_t cfi, uint32_t sf_idx, uint16_t rnti)
{
srslte_dci_location_t locations[MAX_CANDIDATES];
uint32_t nof_locations;
uint32_t nof_formats;
srslte_dci_format_t *formats = NULL;
/* Generate PDCCH candidates */
if (rnti == SRSLTE_SIRNTI) {
nof_locations = srslte_pdcch_common_locations(&q->pdcch, locations, MAX_CANDIDATES, q->cfi);
formats = common_formats;
nof_formats = nof_common_formats;
} else {
nof_locations = srslte_pdcch_ue_locations(&q->pdcch, locations, MAX_CANDIDATES, sf_idx, q->cfi, rnti);
formats = ue_formats;
nof_formats = nof_ue_formats;
}
uint16_t crc_rem = 0;
for (int f=0;f<nof_formats && crc_rem != rnti;f++) {
INFO("Trying format %s\n", srslte_dci_format_string(formats[f]));
for (int i=0;i<nof_locations && crc_rem != rnti;i++) {
q->last_n_cce = locations[i].ncce;
if (srslte_pdcch_decode_msg(&q->pdcch, dci_msg, &locations[i], formats[f], &crc_rem)) {
fprintf(stderr, "Error decoding DCI msg\n");
return SRSLTE_ERROR;
}
if (formats[f] == SRSLTE_DCI_FORMAT1A) {
if (dci_msg->data[0] != 1) {
crc_rem = 0;
}
}
DEBUG("Decoded DCI message RNTI: 0x%x\n", crc_rem);
}
}
if (crc_rem == rnti) {
return 1;
} else {
return 0;
}
}
/* Precalculate the PDSCH scramble sequences for a given RNTI. This function takes a while
* to execute, so shall be called once the final C-RNTI has been allocated for the session.
* For the connection procedure, use srslte_pusch_encode_rnti() or srslte_pusch_decode_rnti() functions
*/
void srslte_ue_dl_set_rnti(srslte_ue_dl_t* q, uint16_t rnti)
{
srslte_pdsch_set_rnti(&q->pdsch, rnti);
srslte_dl_sf_cfg_t sf_cfg;
ZERO_OBJECT(sf_cfg);
// Compute UE-specific and Common search space for this RNTI
for (int i = 0; i < MI_NOF_REGS; i++) {
srslte_pdcch_set_regs(&q->pdcch, &q->regs[i]);
for (int cfi = 0; cfi < 3; cfi++) {
sf_cfg.cfi = cfi + 1;
for (int sf_idx = 0; sf_idx < 10; sf_idx++) {
sf_cfg.tti = sf_idx;
q->current_ss_ue[i][cfi][sf_idx].nof_locations = srslte_pdcch_ue_locations(
&q->pdcch, &sf_cfg, q->current_ss_ue[i][cfi][sf_idx].loc, MAX_CANDIDATES_UE, rnti);
}
q->current_ss_common[i][cfi].nof_locations =
srslte_pdcch_common_locations(&q->pdcch, q->current_ss_common[i][cfi].loc, MAX_CANDIDATES_COM, cfi + 1);
}
}
q->pregen_rnti = rnti;
}
int main(int argc, char **argv) {
srslte_ra_dl_dci_t ra_dl;
int i;
int frame_cnt;
int ret;
srslte_dci_location_t locations[MAX_CANDIDATES];
uint32_t nof_locations;
srslte_dci_msg_t dci_msg;
if (argc < 3) {
usage(argv[0]);
exit(-1);
}
parse_args(argc,argv);
if (base_init()) {
fprintf(stderr, "Error initializing memory\n");
exit(-1);
}
ret = -1;
frame_cnt = 0;
do {
srslte_filesource_read(&fsrc, input_buffer, flen);
INFO("Reading %d samples sub-frame %d\n", flen, frame_cnt);
srslte_ofdm_rx_sf(&fft, input_buffer, fft_buffer);
/* Get channel estimates for each port */
srslte_chest_dl_estimate(&chest, fft_buffer, ce, frame_cnt %10);
uint16_t crc_rem = 0;
if (srslte_pdcch_extract_llr(&pdcch, fft_buffer,
ce, srslte_chest_dl_get_noise_estimate(&chest),
frame_cnt %10, cfi)) {
fprintf(stderr, "Error extracting LLRs\n");
return -1;
}
if (rnti == SRSLTE_SIRNTI) {
INFO("Initializing common search space for SI-RNTI\n",0);
nof_locations = srslte_pdcch_common_locations(&pdcch, locations, MAX_CANDIDATES, cfi);
} else {
INFO("Initializing user-specific search space for RNTI: 0x%x\n", rnti);
nof_locations = srslte_pdcch_ue_locations(&pdcch, locations, MAX_CANDIDATES, frame_cnt %10, cfi, rnti);
}
for (i=0;i<nof_locations && crc_rem != rnti;i++) {
if (srslte_pdcch_decode_msg(&pdcch, &dci_msg, &locations[i], dci_format, &crc_rem)) {
fprintf(stderr, "Error decoding DCI msg\n");
return -1;
}
}
if (crc_rem == rnti) {
srslte_dci_msg_type_t type;
if (srslte_dci_msg_get_type(&dci_msg, &type, cell.nof_prb, rnti)) {
fprintf(stderr, "Can't get DCI message type\n");
exit(-1);
}
printf("MSG %d: ",i);
srslte_dci_msg_type_fprint(stdout, type);
switch(type.type) {
case SRSLTE_DCI_MSG_TYPE_PDSCH_SCHED:
bzero(&ra_dl, sizeof(srslte_ra_dl_dci_t));
if (srslte_dci_msg_unpack_pdsch(&dci_msg, &ra_dl, cell.nof_prb, rnti != SRSLTE_SIRNTI)) {
fprintf(stderr, "Can't unpack DCI message\n");
} else {
srslte_ra_pdsch_fprint(stdout, &ra_dl, cell.nof_prb);
if (ra_dl.alloc_type == SRSLTE_RA_ALLOC_TYPE2 && ra_dl.type2_alloc.mode == SRSLTE_RA_TYPE2_LOC
&& ra_dl.type2_alloc.riv == 11 && ra_dl.rv_idx == 0
&& ra_dl.harq_process == 0 && ra_dl.mcs_idx == 2) {
printf("This is the file signal.1.92M.amar.dat\n");
ret = 0;
}
}
break;
default:
fprintf(stderr, "Unsupported message type\n");
break;
}
}
frame_cnt++;
} while (frame_cnt <= max_frames);
base_free();
exit(ret);
}