/** * * \section COPYRIGHT * * Copyright 2013-2015 Software Radio Systems Limited * * \section LICENSE * * This file is part of the srsLTE library. * * srsLTE is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of * the License, or (at your option) any later version. * * srsLTE is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * A copy of the GNU Affero General Public License can be found in * the LICENSE file in the top-level directory of this distribution * and at http://www.gnu.org/licenses/. * */ #include #include #include #include #include "srslte/phy/phch/pdsch.h" #include "prb_dl.h" #include "srslte/phy/utils/debug.h" #include "srslte/phy/utils/vector.h" #define MAX_PDSCH_RE(cp) (2 * SRSLTE_CP_NSYMB(cp) * 12) const static srslte_mod_t modulations[4] = { SRSLTE_MOD_BPSK, SRSLTE_MOD_QPSK, SRSLTE_MOD_16QAM, SRSLTE_MOD_64QAM }; //#define DEBUG_IDX #ifdef DEBUG_IDX cf_t *offset_original=NULL; extern int indices[100000]; extern int indices_ptr; #endif int srslte_pdsch_cp(srslte_pdsch_t *q, cf_t *input, cf_t *output, srslte_ra_dl_grant_t *grant, uint32_t lstart_grant, uint32_t nsubframe, bool put) { uint32_t s, n, l, lp, lstart, lend, nof_refs; bool is_pbch, is_sss; cf_t *in_ptr = input, *out_ptr = output; uint32_t offset = 0; #ifdef DEBUG_IDX indices_ptr = 0; if (put) { offset_original = output; } else { offset_original = input; } #endif if (q->cell.nof_ports == 1) { nof_refs = 2; } else { nof_refs = 4; } for (s = 0; s < 2; s++) { for (l = 0; l < SRSLTE_CP_NSYMB(q->cell.cp); l++) { for (n = 0; n < q->cell.nof_prb; n++) { // If this PRB is assigned if (grant->prb_idx[s][n]) { if (s == 0) { lstart = lstart_grant; } else { lstart = 0; } lend = SRSLTE_CP_NSYMB(q->cell.cp); is_pbch = is_sss = false; // Skip PSS/SSS signals if (s == 0 && (nsubframe == 0 || nsubframe == 5)) { if (n >= q->cell.nof_prb / 2 - 3 && n < q->cell.nof_prb / 2 + 3 + (q->cell.nof_prb%2)) { lend = SRSLTE_CP_NSYMB(q->cell.cp) - 2; is_sss = true; } } // Skip PBCH if (s == 1 && nsubframe == 0) { if (n >= q->cell.nof_prb / 2 - 3 && n < q->cell.nof_prb / 2 + 3 + (q->cell.nof_prb%2)) { lstart = 4; is_pbch = true; } } lp = l + s * SRSLTE_CP_NSYMB(q->cell.cp); if (put) { out_ptr = &output[(lp * q->cell.nof_prb + n) * SRSLTE_NRE]; } else { in_ptr = &input[(lp * q->cell.nof_prb + n) * SRSLTE_NRE]; } // This is a symbol in a normal PRB with or without references if (l >= lstart && l < lend) { if (SRSLTE_SYMBOL_HAS_REF(l, q->cell.cp, q->cell.nof_ports)) { if (nof_refs == 2) { if (l == 0) { offset = q->cell.id % 6; } else { offset = (q->cell.id + 3) % 6; } } else { offset = q->cell.id % 3; } prb_cp_ref(&in_ptr, &out_ptr, offset, nof_refs, nof_refs, put); } else { prb_cp(&in_ptr, &out_ptr, 1); } } // This is a symbol in a PRB with PBCH or Synch signals (SS). // If the number or total PRB is odd, half of the the PBCH or SS will fall into the symbol if ((q->cell.nof_prb % 2) && ((is_pbch && l < lstart) || (is_sss && l >= lend))) { if (n == q->cell.nof_prb / 2 - 3) { if (SRSLTE_SYMBOL_HAS_REF(l, q->cell.cp, q->cell.nof_ports)) { prb_cp_ref(&in_ptr, &out_ptr, offset, nof_refs, nof_refs/2, put); } else { prb_cp_half(&in_ptr, &out_ptr, 1); } } else if (n == q->cell.nof_prb / 2 + 3) { if (put) { out_ptr += 6; } else { in_ptr += 6; } if (SRSLTE_SYMBOL_HAS_REF(l, q->cell.cp, q->cell.nof_ports)) { prb_cp_ref(&in_ptr, &out_ptr, offset, nof_refs, nof_refs/2, put); } else { prb_cp_half(&in_ptr, &out_ptr, 1); } } } } } } } int r; if (put) { r = abs((int) (input - in_ptr)); } else { r = abs((int) (output - out_ptr)); } return r; } /** * Puts PDSCH in slot number 1 * * Returns the number of symbols written to sf_symbols * * 36.211 10.3 section 6.3.5 */ int srslte_pdsch_put(srslte_pdsch_t *q, cf_t *symbols, cf_t *sf_symbols, srslte_ra_dl_grant_t *grant, uint32_t lstart, uint32_t subframe) { return srslte_pdsch_cp(q, symbols, sf_symbols, grant, lstart, subframe, true); } /** * Extracts PDSCH from slot number 1 * * Returns the number of symbols written to PDSCH * * 36.211 10.3 section 6.3.5 */ int srslte_pdsch_get(srslte_pdsch_t *q, cf_t *sf_symbols, cf_t *symbols, srslte_ra_dl_grant_t *grant, uint32_t lstart, uint32_t subframe) { return srslte_pdsch_cp(q, sf_symbols, symbols, grant, lstart, subframe, false); } /** Initializes the PDCCH transmitter and receiver */ int pdsch_init_multi(srslte_pdsch_t *q, uint32_t max_prb, uint32_t nof_rx_antennas, bool is_ue) { int ret = SRSLTE_ERROR_INVALID_INPUTS; int i; if (q != NULL && nof_rx_antennas <= SRSLTE_MAX_PORTS) { bzero(q, sizeof(srslte_pdsch_t)); ret = SRSLTE_ERROR; q->max_re = max_prb * MAX_PDSCH_RE(q->cell.cp); q->nof_rx_antennas = nof_rx_antennas; INFO("Init PDSCH: %d PRBs, max_symbols: %d\n", max_prb, q->max_re); for (i = 0; i < 4; i++) { if (srslte_modem_table_lte(&q->mod[i], modulations[i])) { goto clean; } srslte_modem_table_bytes(&q->mod[i]); } srslte_sch_init(&q->dl_sch); // Allocate int16_t for reception (LLRs) q->e = srslte_vec_malloc(sizeof(int16_t) * q->max_re * srslte_mod_bits_x_symbol(SRSLTE_MOD_64QAM)); if (!q->e) { goto clean; } q->d = srslte_vec_malloc(sizeof(cf_t) * q->max_re); if (!q->d) { goto clean; } for (i = 0; i < SRSLTE_MAX_PORTS; i++) { q->x[i] = srslte_vec_malloc(sizeof(cf_t) * q->max_re); if (!q->x[i]) { goto clean; } if (is_ue) { for (int j=0;jnof_rx_antennas;j++) { q->ce[i][j] = srslte_vec_malloc(sizeof(cf_t) * q->max_re); if (!q->ce[i][j]) { goto clean; } } } } for (int j=0;jnof_rx_antennas, q->cell.nof_ports);j++) { q->symbols[j] = srslte_vec_malloc(sizeof(cf_t) * q->max_re); if (!q->symbols[j]) { goto clean; } } q->is_ue = is_ue; q->users = calloc(sizeof(srslte_pdsch_user_t*), is_ue?1:(1+SRSLTE_SIRNTI)); if (!q->users) { perror("malloc"); goto clean; } if (srslte_sequence_init(&q->tmp_seq, q->max_re * srslte_mod_bits_x_symbol(SRSLTE_MOD_64QAM))) { goto clean; } ret = SRSLTE_SUCCESS; } clean: if (ret == SRSLTE_ERROR) { srslte_pdsch_free(q); } return ret; } int srslte_pdsch_init_ue(srslte_pdsch_t *q, uint32_t max_prb) { return pdsch_init_multi(q, max_prb, 1, true); } int srslte_pdsch_init_enb(srslte_pdsch_t *q, uint32_t max_prb) { return pdsch_init_multi(q, max_prb, 1, false); } int srslte_pdsch_init_multi_ue(srslte_pdsch_t *q, uint32_t max_prb, uint32_t nof_rx_antennas) { return pdsch_init_multi(q, max_prb, nof_rx_antennas, true); } int srslte_pdsch_init_multi_enb(srslte_pdsch_t *q, uint32_t max_prb, uint32_t nof_rx_antennas) { return pdsch_init_multi(q, max_prb, nof_rx_antennas, false); } void srslte_pdsch_free(srslte_pdsch_t *q) { int i; if (q->e) { free(q->e); } if (q->d) { free(q->d); } for (i = 0; i < SRSLTE_MAX_PORTS; i++) { if (q->x[i]) { free(q->x[i]); } for (int j=0;jnof_rx_antennas;j++) { if (q->ce[i][j]) { free(q->ce[i][j]); } } } for (int j=0;jnof_rx_antennas;j++) { if (q->symbols[j]) { free(q->symbols[j]); } } if (q->users) { if (q->is_ue) { srslte_pdsch_free_rnti(q, 0); } else { for (uint16_t u=0;uusers[u]) { srslte_pdsch_free_rnti(q, u); } } } free(q->users); } srslte_sequence_free(&q->tmp_seq); for (i = 0; i < 4; i++) { srslte_modem_table_free(&q->mod[i]); } srslte_sch_free(&q->dl_sch); bzero(q, sizeof(srslte_pdsch_t)); } int srslte_pdsch_set_cell(srslte_pdsch_t *q, srslte_cell_t cell) { int ret = SRSLTE_ERROR_INVALID_INPUTS; if (q != NULL && srslte_cell_isvalid(&cell)) { memcpy(&q->cell, &cell, sizeof(srslte_cell_t)); q->max_re = q->cell.nof_prb * MAX_PDSCH_RE(q->cell.cp); INFO("PDSCH: Cell config PCI=%d, %d ports, %d PRBs, max_symbols: %d\n", q->cell.nof_ports, q->cell.id, q->cell.nof_prb, q->max_re); ret = SRSLTE_SUCCESS; } return ret; } /* Configures the structure srslte_pdsch_cfg_t from the DL DCI allocation dci_msg. * If dci_msg is NULL, the grant is assumed to be already stored in cfg->grant */ int srslte_pdsch_cfg(srslte_pdsch_cfg_t *cfg, srslte_cell_t cell, srslte_ra_dl_grant_t *grant, uint32_t cfi, uint32_t sf_idx, uint32_t rvidx) { if (cfg) { if (grant) { memcpy(&cfg->grant, grant, sizeof(srslte_ra_dl_grant_t)); } if (srslte_cbsegm(&cfg->cb_segm, cfg->grant.mcs.tbs)) { fprintf(stderr, "Error computing Codeblock segmentation for TBS=%d\n", cfg->grant.mcs.tbs); return SRSLTE_ERROR; } srslte_ra_dl_grant_to_nbits(&cfg->grant, cfi, cell, sf_idx, &cfg->nbits); cfg->sf_idx = sf_idx; cfg->rv = rvidx; return SRSLTE_SUCCESS; } else { return SRSLTE_ERROR_INVALID_INPUTS; } } /* 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. */ int srslte_pdsch_set_rnti(srslte_pdsch_t *q, uint16_t rnti) { uint32_t i; uint32_t rnti_idx = q->is_ue?0:rnti; if (!q->users[rnti_idx]) { q->users[rnti_idx] = calloc(1, sizeof(srslte_pdsch_user_t)); if (q->users[rnti_idx]) { for (i = 0; i < SRSLTE_NSUBFRAMES_X_FRAME; i++) { if (srslte_sequence_pdsch(&q->users[rnti_idx]->seq[i], rnti, 0, 2 * i, q->cell.id, q->max_re * srslte_mod_bits_x_symbol(SRSLTE_MOD_64QAM))) { return SRSLTE_ERROR; } } q->users[rnti_idx]->sequence_generated = true; } } return SRSLTE_SUCCESS; } void srslte_pdsch_free_rnti(srslte_pdsch_t* q, uint16_t rnti) { uint32_t rnti_idx = q->is_ue?0:rnti; if (q->users[rnti_idx]) { for (int i = 0; i < SRSLTE_NSUBFRAMES_X_FRAME; i++) { srslte_sequence_free(&q->users[rnti_idx]->seq[i]); } free(q->users[rnti_idx]); q->users[rnti_idx] = NULL; } } int srslte_pdsch_decode(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) { cf_t *_sf_symbols[SRSLTE_MAX_PORTS]; cf_t *_ce[SRSLTE_MAX_PORTS][SRSLTE_MAX_PORTS]; _sf_symbols[0] = sf_symbols; for (int i=0;icell.nof_ports;i++) { _ce[i][0] = ce[i]; } return srslte_pdsch_decode_multi(q, cfg, softbuffer, _sf_symbols, _ce, noise_estimate, rnti, data); } static srslte_sequence_t *get_user_sequence(srslte_pdsch_t *q, uint16_t rnti, uint32_t sf_idx, uint32_t len) { uint32_t rnti_idx = q->is_ue?0:rnti; if (q->users[rnti_idx] && q->users[rnti_idx]->sequence_generated) { return &q->users[rnti_idx]->seq[sf_idx]; } else { srslte_sequence_pdsch(&q->tmp_seq, rnti, 0, 2 * sf_idx, q->cell.id, len); return &q->tmp_seq; } } /** Decodes the PDSCH from the received symbols */ int srslte_pdsch_decode_multi(srslte_pdsch_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 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)); for (int j=0;jnof_rx_antennas;j++) { /* extract symbols */ n = srslte_pdsch_get(q, sf_symbols[j], q->symbols[j], &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][j], q->ce[i][j], &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_multi(q->symbols, q->ce[0], q->d, q->nof_rx_antennas, cfg->nbits.nof_re, noise_estimate); } else { srslte_predecoding_diversity_multi(q->symbols, q->ce, x, q->nof_rx_antennas, q->cell.nof_ports, cfg->nbits.nof_re); 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 subframe.dat: received subframe symbols\n",0); srslte_vec_save_file("subframe.dat", sf_symbols[0], SRSLTE_SF_LEN_RE(q->cell.nof_prb, q->cell.cp)*sizeof(cf_t)); DEBUG("SAVED FILE hest0.dat and hest1.dat: channel estimates for port 0 and port 1\n",0); srslte_vec_save_file("hest0.dat", ce[0][0], SRSLTE_SF_LEN_RE(q->cell.nof_prb, q->cell.cp)*sizeof(cf_t)); if (q->cell.nof_ports > 1) { srslte_vec_save_file("hest1.dat", ce[1][0], SRSLTE_SF_LEN_RE(q->cell.nof_prb, q->cell.cp)*sizeof(cf_t)); } 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); // Generate scrambling sequence if not pre-generated srslte_sequence_t *seq = get_user_sequence(q, rnti, cfg->sf_idx, cfg->nbits.nof_bits); // Run scrambling srslte_scrambling_s_offset(seq, 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; } } int srslte_pdsch_encode(srslte_pdsch_t *q, srslte_pdsch_cfg_t *cfg, srslte_softbuffer_tx_t *softbuffer, uint8_t *data, uint16_t rnti, cf_t *sf_symbols[SRSLTE_MAX_PORTS]) { int i; /* Set pointers for layermapping & precoding */ cf_t *x[SRSLTE_MAX_LAYERS]; int ret = SRSLTE_ERROR_INVALID_INPUTS; if (q != NULL && cfg != NULL) { for (i=0;icell.nof_ports;i++) { if (sf_symbols[i] == NULL) { return SRSLTE_ERROR_INVALID_INPUTS; } } if (cfg->grant.mcs.tbs == 0) { return SRSLTE_ERROR_INVALID_INPUTS; } if (cfg->nbits.nof_re > q->max_re) { fprintf(stderr, "Error too many RE per subframe (%d). PDSCH configured for %d RE (%d PRB)\n", cfg->nbits.nof_re, q->max_re, q->cell.nof_prb); return SRSLTE_ERROR_INVALID_INPUTS; } INFO("Encoding PDSCH SF: %d, Mod %s, NofBits: %d, NofSymbols: %d, NofBitsE: %d, rv_idx: %d\n", cfg->sf_idx, srslte_mod_string(cfg->grant.mcs.mod), cfg->grant.mcs.tbs, cfg->nbits.nof_re, cfg->nbits.nof_bits, cfg->rv); /* 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)); if (srslte_dlsch_encode(&q->dl_sch, cfg, softbuffer, data, q->e)) { fprintf(stderr, "Error encoding TB\n"); return SRSLTE_ERROR; } // Generate scrambling sequence if not pre-generated srslte_sequence_t *seq = get_user_sequence(q, rnti, cfg->sf_idx, cfg->nbits.nof_bits); srslte_scrambling_bytes(seq, (uint8_t*) q->e, cfg->nbits.nof_bits); srslte_mod_modulate_bytes(&q->mod[cfg->grant.mcs.mod], (uint8_t*) q->e, q->d, cfg->nbits.nof_bits); /* TODO: only diversity supported */ if (q->cell.nof_ports > 1) { srslte_layermap_diversity(q->d, x, q->cell.nof_ports, cfg->nbits.nof_re); srslte_precoding_diversity(x, q->symbols, q->cell.nof_ports, cfg->nbits.nof_re / q->cell.nof_ports); } else { memcpy(q->symbols[0], q->d, cfg->nbits.nof_re * sizeof(cf_t)); } /* mapping to resource elements */ for (i = 0; i < q->cell.nof_ports; i++) { srslte_pdsch_put(q, q->symbols[i], sf_symbols[i], &cfg->grant, cfg->nbits.lstart, cfg->sf_idx); } ret = SRSLTE_SUCCESS; } return ret; } float srslte_pdsch_average_noi(srslte_pdsch_t *q) { return q->dl_sch.average_nof_iterations; } uint32_t srslte_pdsch_last_noi(srslte_pdsch_t *q) { return q->dl_sch.nof_iterations; }