/** Decodes the pmch from the received symbols */ int srslte_pmch_decode_multi(srslte_pmch_t *q, srslte_pdsch_cfg_t *cfg, srslte_softbuffer_rx_t *softbuffer, cf_t *sf_symbols[SRSLTE_MAX_PORTS], cf_t *ce[SRSLTE_MAX_PORTS][SRSLTE_MAX_PORTS], float noise_estimate, uint16_t area_id, uint8_t *data) { /* Set pointers for layermapping & precoding */ uint32_t i, n; cf_t *x[SRSLTE_MAX_LAYERS]; if (q != NULL && sf_symbols != NULL && data != NULL && cfg != NULL) { INFO("Decoding PMCH SF: %d, MBSFN area ID: 0x%x, Mod %s, TBS: %d, NofSymbols: %d, NofBitsE: %d, rv_idx: %d, C_prb=%d, cfi=%d\n", cfg->sf_idx, area_id, srslte_mod_string(cfg->grant.mcs[0].mod), cfg->grant.mcs[0].tbs, cfg->nbits[0].nof_re, cfg->nbits[0].nof_bits, 0, cfg->grant.nof_prb, cfg->nbits[0].lstart-1); /* 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)); for (int j=0;j<q->nof_rx_antennas;j++) { /* extract symbols */ n = srslte_pmch_get(q, sf_symbols[j], q->symbols[j], cfg->nbits[0].lstart); if (n != cfg->nbits[0].nof_re) { fprintf(stderr, "PMCH 1 extract symbols error expecting %d symbols but got %d, lstart %d\n", cfg->nbits[0].nof_re, n, cfg->nbits[0].lstart); return SRSLTE_ERROR; } /* extract channel estimates */ for (i = 0; i < q->cell.nof_ports; i++) { n = srslte_pmch_get(q, ce[i][j], q->ce[i][j], cfg->nbits[0].lstart); if (n != cfg->nbits[0].nof_re) { fprintf(stderr, "PMCH 2 extract chest error expecting %d symbols but got %d\n", cfg->nbits[0].nof_re, n); return SRSLTE_ERROR; } } } // No tx diversity in MBSFN srslte_predecoding_single_multi(q->symbols, q->ce[0], q->d, NULL, q->nof_rx_antennas, cfg->nbits[0].nof_re, 1.0f, noise_estimate); if (SRSLTE_VERBOSE_ISDEBUG()) { DEBUG("SAVED FILE subframe.dat: received subframe symbols\n"); srslte_vec_save_file("subframe.dat", sf_symbols, SRSLTE_SF_LEN_RE(q->cell.nof_prb, q->cell.cp)*sizeof(cf_t)); DEBUG("SAVED FILE hest0.dat: channel estimates for port 4\n"); srslte_vec_save_file("hest0.dat", ce[0], SRSLTE_SF_LEN_RE(q->cell.nof_prb, q->cell.cp)*sizeof(cf_t)); DEBUG("SAVED FILE pmch_symbols.dat: symbols after equalization\n"); srslte_vec_save_file("pmch_symbols.bin", q->d, cfg->nbits[0].nof_re*sizeof(cf_t)); } /* demodulate symbols * The MAX-log-MAP algorithm used in turbo decoding is unsensitive to SNR estimation, * thus we don't need tot set it in thde LLRs normalization */ srslte_demod_soft_demodulate_s(cfg->grant.mcs[0].mod, q->d, q->e, cfg->nbits[0].nof_re); /* descramble */ srslte_scrambling_s_offset(&q->seqs[area_id]->seq[cfg->sf_idx], q->e, 0, cfg->nbits[0].nof_bits); if (SRSLTE_VERBOSE_ISDEBUG()) { DEBUG("SAVED FILE llr.dat: LLR estimates after demodulation and descrambling\n"); srslte_vec_save_file("llr.dat", q->e, cfg->nbits[0].nof_bits*sizeof(int16_t)); } return srslte_dlsch_decode(&q->dl_sch, cfg, softbuffer, q->e, data); } else { return SRSLTE_ERROR_INVALID_INPUTS; } }
/** Decodes the PDSCH from the received symbols */ int srslte_pdsch_decode_rnti(srslte_pdsch_t *q, srslte_pdsch_cfg_t *cfg, srslte_softbuffer_rx_t *softbuffer, cf_t *sf_symbols, cf_t *ce[SRSLTE_MAX_PORTS], float noise_estimate, uint16_t rnti, uint8_t *data) { /* Set pointers for layermapping & precoding */ uint32_t i, n; cf_t *x[SRSLTE_MAX_LAYERS]; if (q != NULL && sf_symbols != NULL && data != NULL && cfg != NULL) { INFO("Decoding PDSCH SF: %d, RNTI: 0x%x, Mod %s, TBS: %d, NofSymbols: %d, NofBitsE: %d, rv_idx: %d, C_prb=%d\n", cfg->sf_idx, rnti, srslte_mod_string(cfg->grant.mcs.mod), cfg->grant.mcs.tbs, cfg->nbits.nof_re, cfg->nbits.nof_bits, cfg->rv, cfg->grant.nof_prb); /* 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)); /* extract symbols */ n = srslte_pdsch_get(q, sf_symbols, q->symbols[0], &cfg->grant, cfg->nbits.lstart, cfg->sf_idx); if (n != cfg->nbits.nof_re) { fprintf(stderr, "Error expecting %d symbols but got %d\n", cfg->nbits.nof_re, n); return SRSLTE_ERROR; } /* extract channel estimates */ for (i = 0; i < q->cell.nof_ports; i++) { n = srslte_pdsch_get(q, ce[i], q->ce[i], &cfg->grant, cfg->nbits.lstart, cfg->sf_idx); if (n != cfg->nbits.nof_re) { fprintf(stderr, "Error expecting %d symbols but got %d\n", cfg->nbits.nof_re, n); return SRSLTE_ERROR; } } /* TODO: only diversity is supported */ if (q->cell.nof_ports == 1) { /* no need for layer demapping */ srslte_predecoding_single(q->symbols[0], q->ce[0], q->d, cfg->nbits.nof_re, noise_estimate); } else { srslte_predecoding_diversity(&q->precoding, q->symbols[0], q->ce, x, q->cell.nof_ports, cfg->nbits.nof_re, noise_estimate); srslte_layerdemap_diversity(x, q->d, q->cell.nof_ports, cfg->nbits.nof_re / q->cell.nof_ports); } if (SRSLTE_VERBOSE_ISDEBUG()) { DEBUG("SAVED FILE pdsch_symbols.dat: symbols after equalization\n",0); srslte_vec_save_file("pdsch_symbols.dat", q->d, cfg->nbits.nof_re*sizeof(cf_t)); } /* demodulate symbols * The MAX-log-MAP algorithm used in turbo decoding is unsensitive to SNR estimation, * thus we don't need tot set it in the LLRs normalization */ srslte_demod_soft_demodulate_s(cfg->grant.mcs.mod, q->d, q->e, cfg->nbits.nof_re); /* descramble */ 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_s_offset(&seq, q->e, 0, cfg->nbits.nof_bits); srslte_sequence_free(&seq); } else { srslte_scrambling_s_offset(&q->seq[cfg->sf_idx], q->e, 0, cfg->nbits.nof_bits); } if (SRSLTE_VERBOSE_ISDEBUG()) { DEBUG("SAVED FILE llr.dat: LLR estimates after demodulation and descrambling\n",0); srslte_vec_save_file("llr.dat", q->e, cfg->nbits.nof_bits*sizeof(int16_t)); } return srslte_dlsch_decode(&q->dl_sch, cfg, softbuffer, q->e, data); } else { return SRSLTE_ERROR_INVALID_INPUTS; } }