static int srslte_pdsch_codeword_decode(srslte_pdsch_t *q, srslte_pdsch_cfg_t *cfg, srslte_softbuffer_rx_t *softbuffer, uint16_t rnti, uint8_t *data, uint32_t codeword_idx, uint32_t tb_idx, bool *ack) { srslte_ra_nbits_t *nbits = &cfg->nbits[tb_idx]; srslte_ra_mcs_t *mcs = &cfg->grant.mcs[tb_idx]; uint32_t rv = cfg->rv[tb_idx]; int ret = SRSLTE_ERROR_INVALID_INPUTS; if (softbuffer && data && ack) { INFO("Decoding PDSCH SF: %d (CW%d -> TB%d), Mod %s, NofBits: %d, NofSymbols: %d, NofBitsE: %d, rv_idx: %d\n", cfg->sf_idx, codeword_idx, tb_idx, srslte_mod_string(mcs->mod), mcs->tbs, nbits->nof_re, nbits->nof_bits, rv); /* 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(mcs->mod, q->d[codeword_idx], q->e[codeword_idx], nbits->nof_re); /* Select scrambling sequence */ srslte_sequence_t *seq = get_user_sequence(q, rnti, codeword_idx, cfg->sf_idx, nbits->nof_bits); /* Bit scrambling */ srslte_scrambling_s_offset(seq, q->e[codeword_idx], 0, nbits->nof_bits); /* Return */ ret = srslte_dlsch_decode2(&q->dl_sch, cfg, softbuffer, q->e[codeword_idx], data, tb_idx); q->last_nof_iterations[codeword_idx] = srslte_sch_last_noi(&q->dl_sch); if (ret == SRSLTE_SUCCESS) { *ack = true; } else if (ret == SRSLTE_ERROR) { *ack = false; ret = SRSLTE_SUCCESS; } else if (ret == SRSLTE_ERROR_INVALID_INPUTS) { *ack = false; ret = SRSLTE_ERROR; } } else { ERROR("Detected NULL pointer in TB%d &softbuffer=%p &data=%p &ack=%p", codeword_idx, softbuffer, (void*)data, ack); } return ret; }
void srslte_scrambling_s(srslte_sequence_t *s, short *data) { srslte_scrambling_s_offset(s, data, 0, s->cur_len); }
/** 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; } }
static int srslte_pdsch_codeword_decode(srslte_pdsch_t *q, srslte_pdsch_cfg_t *cfg, srslte_softbuffer_rx_t *softbuffer, uint16_t rnti, uint8_t *data, uint32_t codeword_idx, uint32_t tb_idx, bool *ack) { srslte_ra_nbits_t *nbits = &cfg->nbits[tb_idx]; srslte_ra_mcs_t *mcs = &cfg->grant.mcs[tb_idx]; uint32_t rv = cfg->rv[tb_idx]; int ret = SRSLTE_ERROR_INVALID_INPUTS; if (softbuffer && data && ack) { INFO("Decoding PDSCH SF: %d (CW%d -> TB%d), Mod %s, NofBits: %d, NofSymbols: %d, NofBitsE: %d, rv_idx: %d\n", cfg->sf_idx, codeword_idx, tb_idx, srslte_mod_string(mcs->mod), mcs->tbs, nbits->nof_re, nbits->nof_bits, rv); /* 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(mcs->mod, q->d[codeword_idx], q->e[codeword_idx], nbits->nof_re); /* Select scrambling sequence */ srslte_sequence_t *seq = get_user_sequence(q, rnti, codeword_idx, cfg->sf_idx, nbits->nof_bits); /* Bit scrambling */ srslte_scrambling_s_offset(seq, q->e[codeword_idx], 0, nbits->nof_bits); uint32_t qm = nbits->nof_bits/nbits->nof_re; switch(cfg->grant.mcs[tb_idx].mod) { case SRSLTE_MOD_BPSK: qm = 1; break; case SRSLTE_MOD_QPSK: qm = 2; break; case SRSLTE_MOD_16QAM: qm = 4; break; case SRSLTE_MOD_64QAM: qm = 6; break; default: ERROR("No modulation"); } int16_t *e = q->e[codeword_idx]; if (q->csi_enabled) { const uint32_t csi_max_idx = srslte_vec_max_fi(q->csi[codeword_idx], nbits->nof_bits / qm); float csi_max = 1.0f; if (csi_max_idx < nbits->nof_bits / qm) { csi_max = q->csi[codeword_idx][csi_max_idx]; } for (int i = 0; i < nbits->nof_bits / qm; i++) { const float csi = q->csi[codeword_idx][i] / csi_max; for (int k = 0; k < qm; k++) { e[qm * i + k] = (int16_t) ((float) e[qm * i + k] * csi); } } } /* Return */ ret = srslte_dlsch_decode2(&q->dl_sch, cfg, softbuffer, q->e[codeword_idx], data, tb_idx); q->last_nof_iterations[codeword_idx] = srslte_sch_last_noi(&q->dl_sch); if (ret == SRSLTE_SUCCESS) { *ack = true; } else if (ret == SRSLTE_ERROR) { *ack = false; ret = SRSLTE_SUCCESS; } else if (ret == SRSLTE_ERROR_INVALID_INPUTS) { *ack = false; ret = SRSLTE_ERROR; } } else { ERROR("Detected NULL pointer in TB%d &softbuffer=%p &data=%p &ack=%p", codeword_idx, softbuffer, (void*)data, ack); } return ret; }