int srslte_ue_dl_decode_phich(srslte_ue_dl_t* q,
srslte_dl_sf_cfg_t* sf,
srslte_ue_dl_cfg_t* cfg,
srslte_phich_grant_t* grant,
srslte_phich_res_t* result)
{
srslte_phich_resource_t n_phich;
uint32_t sf_idx = sf->tti % 10;
set_mi_value(q, sf, cfg);
srslte_phich_calc(&q->phich, grant, &n_phich);
INFO("Decoding PHICH sf_idx=%d, n_prb_lowest=%d, n_dmrs=%d, I_phich=%d, n_group=%d, n_seq=%d, Ngroups=%d, Nsf=%d\n",
sf_idx,
grant->n_prb_lowest,
grant->n_dmrs,
grant->I_phich,
n_phich.ngroup,
n_phich.nseq,
srslte_phich_ngroups(&q->phich),
srslte_phich_nsf(&q->phich));
if (!srslte_phich_decode(&q->phich, sf, &q->chest_res, n_phich, q->sf_symbols, result)) {
INFO("Decoded PHICH %d with distance %f\n", result->ack_value, result->distance);
return 0;
} else {
ERROR("Error decoding PHICH\n");
return -1;
}
}
/* Computes n_group and n_seq according to Section 9.1.2 in 36.213 and calls phich processing function */
bool srslte_ue_dl_decode_phich(srslte_ue_dl_t *q, uint32_t sf_idx, uint32_t n_prb_lowest, uint32_t n_dmrs)
{
uint8_t ack_bit;
float distance;
uint32_t Ngroups = srslte_phich_ngroups(&q->phich);
uint32_t ngroup = (n_prb_lowest+n_dmrs)%Ngroups;
uint32_t nseq = ((n_prb_lowest/Ngroups)+n_dmrs)%(2*srslte_phich_nsf(&q->phich));
DEBUG("Decoding PHICH sf_idx=%d, n_prb_lowest=%d, n_dmrs=%d, n_group=%d, n_seq=%d\n",
sf_idx, n_prb_lowest, n_dmrs, ngroup, nseq);
if (!srslte_phich_decode(&q->phich, q->sf_symbols, q->ce, 0, ngroup, nseq, sf_idx, &ack_bit, &distance)) {
INFO("Decoded PHICH %d with distance %f\n", ack_bit, distance);
} else {
fprintf(stderr, "Error decoding PHICH\n");
return false;
}
if (ack_bit && distance > 1.5) {
return true;
} else {
return false;
}
}
bool srslte_ue_dl_decode_phich(srslte_ue_dl_t *q, uint32_t sf_idx, uint32_t n_prb_lowest, uint32_t n_dmrs)
{
uint8_t ack_bit;
float distance;
uint32_t ngroup, nseq;
srslte_phich_calc(&q->phich, n_prb_lowest, n_dmrs, &ngroup, &nseq);
INFO("Decoding PHICH sf_idx=%d, n_prb_lowest=%d, n_dmrs=%d, n_group=%d, n_seq=%d, Ngroups=%d, Nsf=%d\n",
sf_idx, n_prb_lowest, n_dmrs, ngroup, nseq,
srslte_phich_ngroups(&q->phich), srslte_phich_nsf(&q->phich));
if (!srslte_phich_decode(&q->phich, q->sf_symbols_m, q->ce_m, 0, ngroup, nseq, sf_idx, &ack_bit, &distance)) {
q->last_phich_corr = distance;
INFO("Decoded PHICH %d with distance %f\n", ack_bit, distance);
} else {
fprintf(stderr, "Error decoding PHICH\n");
return false;
}
if (ack_bit) {
return true;
} else {
return false;
}
}
int main(int argc, char **argv) {
srslte_phich_t phich;
srslte_regs_t regs;
int i, j;
cf_t *ce[SRSLTE_MAX_PORTS];
int nof_re;
cf_t *slot_symbols[SRSLTE_MAX_PORTS];
uint8_t ack[50][SRSLTE_PHICH_NORM_NSEQUENCES], ack_rx;
uint32_t nsf;
float distance;
int cid, max_cid;
uint32_t ngroup, nseq, max_nseq;
parse_args(argc,argv);
max_nseq = SRSLTE_CP_ISNORM(cell.cp)?SRSLTE_PHICH_NORM_NSEQUENCES:SRSLTE_PHICH_EXT_NSEQUENCES;
nof_re = SRSLTE_CP_NORM_NSYMB * cell.nof_prb * SRSLTE_NRE;
/* init memory */
for (i=0;i<SRSLTE_MAX_PORTS;i++) {
ce[i] = malloc(sizeof(cf_t) * nof_re);
if (!ce[i]) {
perror("malloc");
exit(-1);
}
for (j=0;j<nof_re;j++) {
ce[i][j] = 1;
}
slot_symbols[i] = malloc(sizeof(cf_t) * nof_re);
if (!slot_symbols[i]) {
perror("malloc");
exit(-1);
}
}
if (cell.id == 1000) {
cid = 0;
max_cid = 503;
} else {
cid = cell.id;
max_cid = cell.id;
}
while(cid <= max_cid) {
cell.id = cid;
printf("Testing CellID=%d...\n", cid);
if (srslte_regs_init(®s, cell)) {
fprintf(stderr, "Error initiating regs\n");
exit(-1);
}
if (srslte_phich_init(&phich, ®s, cell)) {
fprintf(stderr, "Error creating PBCH object\n");
exit(-1);
}
for (nsf=0;nsf<10;nsf++) {
srslte_phich_reset(&phich, slot_symbols);
/* Transmit all PHICH groups and sequence numbers */
for (ngroup=0;ngroup<srslte_phich_ngroups(&phich);ngroup++) {
for (nseq=0;nseq<max_nseq;nseq++) {
ack[ngroup][nseq] = rand()%2;
srslte_phich_encode(&phich, ack[ngroup][nseq], ngroup, nseq, nsf, slot_symbols);
}
}
/* combine outputs */
for (i=1;i<cell.nof_ports;i++) {
for (j=0;j<nof_re;j++) {
slot_symbols[0][j] += slot_symbols[i][j];
}
}
/* Receive all PHICH groups and sequence numbers */
for (ngroup=0;ngroup<srslte_phich_ngroups(&phich);ngroup++) {
for (nseq=0;nseq<max_nseq;nseq++) {
if (srslte_phich_decode(&phich, slot_symbols[0], ce, 0, ngroup, nseq, nsf, &ack_rx, &distance)<0) {
printf("Error decoding ACK\n");
exit(-1);
}
INFO("%d/%d, ack_tx: %d, ack_rx: %d, ns: %d, distance: %f\n",
ngroup, nseq, ack[ngroup][nseq], ack_rx, nsf, distance);
if (ack[ngroup][nseq] != ack_rx) {
printf("Invalid received ACK: %d!=%d\n", ack[ngroup][nseq], ack_rx);
exit(-1);
}
if (distance < 1.5) {
printf("Error\n");
exit(-1);
}
}
}
}
srslte_phich_free(&phich);
srslte_regs_free(®s);
cid++;
}
for (i=0;i<SRSLTE_MAX_PORTS;i++) {
free(ce[i]);
free(slot_symbols[i]);
}
printf("OK\n");
exit(0);
}
/* the gateway function */
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
int i;
srslte_cell_t cell;
srslte_phich_t phich;
srslte_chest_dl_t chest;
srslte_ofdm_t ofdm_rx;
srslte_regs_t regs;
uint32_t sf_idx;
cf_t *input_fft, *input_signal;
if (nrhs < NOF_INPUTS) {
help();
return;
}
if (mexutils_read_cell(ENBCFG, &cell)) {
help();
return;
}
if (mexutils_read_uint32_struct(ENBCFG, "NSubframe", &sf_idx)) {
help();
return;
}
if (srslte_chest_dl_init(&chest, cell)) {
mexErrMsgTxt("Error initializing equalizer\n");
return;
}
if (srslte_ofdm_rx_init(&ofdm_rx, cell.cp, cell.nof_prb)) {
mexErrMsgTxt("Error initializing FFT\n");
return;
}
if (srslte_regs_init(®s, cell)) {
mexErrMsgTxt("Error initiating regs\n");
return;
}
if (srslte_phich_init(&phich, ®s, cell)) {
mexErrMsgTxt("Error creating PHICH object\n");
return;
}
// Read input signal
input_signal = NULL;
int insignal_len = mexutils_read_cf(INPUT, &input_signal);
if (insignal_len < 0) {
mexErrMsgTxt("Error reading input signal\n");
return;
}
if (insignal_len == SRSLTE_SF_LEN_RE(cell.nof_prb, cell.cp)) {
input_fft = input_signal;
} else {
input_fft = srslte_vec_malloc(SRSLTE_SF_LEN_RE(cell.nof_prb, cell.cp) * sizeof(cf_t));
srslte_ofdm_rx_sf(&ofdm_rx, input_signal, input_fft);
free(input_signal);
}
cf_t *ce[SRSLTE_MAX_PORTS];
for (i=0;i<cell.nof_ports;i++) {
ce[i] = srslte_vec_malloc(SRSLTE_SF_LEN_RE(cell.nof_prb, cell.cp) * sizeof(cf_t));
}
if (nrhs > NOF_INPUTS) {
cf_t *cearray = NULL;
mexutils_read_cf(prhs[NOF_INPUTS], &cearray);
cf_t *cearray_ptr = cearray;
for (i=0;i<cell.nof_ports;i++) {
for (int j=0;j<SRSLTE_SF_LEN_RE(cell.nof_prb, cell.cp);j++) {
ce[i][j] = *cearray_ptr;
cearray_ptr++;
}
}
if (cearray) {
free(cearray);
}
} else {
srslte_chest_dl_estimate(&chest, input_fft, ce, sf_idx);
}
float noise_power;
if (nrhs > NOF_INPUTS + 1) {
noise_power = mxGetScalar(prhs[NOF_INPUTS+1]);
} else if (nrhs > NOF_INPUTS) {
noise_power = 0;
} else {
noise_power = srslte_chest_dl_get_noise_estimate(&chest);
}
// Read hires values
float *hires = NULL;
int nhires = mexutils_read_f(HIRES, &hires);
if (nhires != 2) {
mexErrMsgTxt("Expecting 2 values for hires parameter\n");
return;
}
uint32_t ngroup = (uint32_t) hires[0];
uint32_t nseq = (uint32_t) hires[1];
uint8_t ack;
float corr_res;
int n = srslte_phich_decode(&phich, input_fft, ce, noise_power, ngroup, nseq, sf_idx, &ack, &corr_res);
if (nlhs >= 1) {
if (n < 0) {
plhs[0] = mxCreateDoubleScalar(-1);
} else {
plhs[0] = mxCreateDoubleScalar(ack);
}
}
if (nlhs >= 2) {
mexutils_write_cf(phich.z, &plhs[1], 1, SRSLTE_PHICH_NBITS);
}
srslte_chest_dl_free(&chest);
srslte_ofdm_rx_free(&ofdm_rx);
srslte_phich_free(&phich);
srslte_regs_free(®s);
for (i=0;i<cell.nof_ports;i++) {
free(ce[i]);
}
free(input_fft);
return;
}
