/** * * \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 #include #include #include #include #include #include "srslte/phy/ch_estimation/refsignal_ul.h" #include "srslte/phy/phch/pusch.h" #include "srslte/phy/phch/pusch_cfg.h" #include "srslte/phy/phch/uci.h" #include "srslte/phy/common/phy_common.h" #include "srslte/phy/utils/bit.h" #include "srslte/phy/utils/debug.h" #include "srslte/phy/utils/vector.h" #include "srslte/phy/dft/dft_precoding.h" #define MAX_PUSCH_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 }; static int f_hop_sum(srslte_pusch_t *q, uint32_t i) { uint32_t sum = 0; for (uint32_t k=i*10+1;kseq_type2_fo.c[k]<<(k-(i*10+1))); } return sum; } static int f_hop(srslte_pusch_t *q, srslte_pusch_hopping_cfg_t *hopping, int i) { if (i == -1) { return 0; } else { if (hopping->n_sb == 1) { return 0; } else if (hopping->n_sb == 2) { return (f_hop(q, hopping, i-1) + f_hop_sum(q, i))%2; } else { return (f_hop(q, hopping, i-1) + f_hop_sum(q, i)%(hopping->n_sb-1)+1)%hopping->n_sb; } } } static int f_m(srslte_pusch_t *q, srslte_pusch_hopping_cfg_t *hopping, uint32_t i, uint32_t current_tx_nb) { if (hopping->n_sb == 1) { if (hopping->hop_mode == SRSLTE_PUSCH_HOP_MODE_INTER_SF) { return current_tx_nb%2; } else { return i%2; } } else { return q->seq_type2_fo.c[i*10]; } } /* Computes PUSCH frequency hopping as defined in Section 8.4 of 36.213 */ void compute_freq_hopping(srslte_pusch_t *q, srslte_ra_ul_grant_t *grant, srslte_pusch_hopping_cfg_t *hopping, uint32_t sf_idx, uint32_t current_tx_nb) { for (uint32_t slot=0;slot<2;slot++) { INFO("PUSCH Freq hopping: %d\n", grant->freq_hopping); uint32_t n_prb_tilde = grant->n_prb[slot]; if (grant->freq_hopping == 1) { if (hopping->hop_mode == SRSLTE_PUSCH_HOP_MODE_INTER_SF) { n_prb_tilde = grant->n_prb[current_tx_nb%2]; } else { n_prb_tilde = grant->n_prb[slot]; } } if (grant->freq_hopping == 2) { /* Freq hopping type 2 as defined in 5.3.4 of 36.211 */ uint32_t n_vrb_tilde = grant->n_prb[0]; if (hopping->n_sb > 1) { n_vrb_tilde -= (hopping->hopping_offset-1)/2+1; } int i=0; if (hopping->hop_mode == SRSLTE_PUSCH_HOP_MODE_INTER_SF) { i = sf_idx; } else { i = 2*sf_idx+slot; } uint32_t n_rb_sb = q->cell.nof_prb; if (hopping->n_sb > 1) { n_rb_sb = (n_rb_sb-hopping->hopping_offset-hopping->hopping_offset%2)/hopping->n_sb; } n_prb_tilde = (n_vrb_tilde+f_hop(q, hopping, i)*n_rb_sb+ (n_rb_sb-1)-2*(n_vrb_tilde%n_rb_sb)*f_m(q, hopping, i, current_tx_nb))%(n_rb_sb*hopping->n_sb); INFO("n_prb_tilde: %d, n_vrb_tilde: %d, n_rb_sb: %d, n_sb: %d\n", n_prb_tilde, n_vrb_tilde, n_rb_sb, hopping->n_sb); if (hopping->n_sb > 1) { n_prb_tilde += (hopping->hopping_offset-1)/2+1; } } grant->n_prb_tilde[slot] = n_prb_tilde; } } /* Allocate/deallocate PUSCH RBs to the resource grid */ int pusch_cp(srslte_pusch_t *q, srslte_ra_ul_grant_t *grant, cf_t *input, cf_t *output, bool advance_input) { cf_t *in_ptr = input; cf_t *out_ptr = output; uint32_t L_ref = 3; if (SRSLTE_CP_ISEXT(q->cell.cp)) { L_ref = 2; } for (uint32_t slot=0;slot<2;slot++) { uint32_t N_srs = 0; if (q->shortened && slot == 1) { N_srs = 1; } INFO("%s PUSCH %d PRB to index %d at slot %d\n",advance_input?"Allocating":"Getting",grant->L_prb, grant->n_prb_tilde[slot], slot); for (uint32_t l=0;lcell.cp)-N_srs;l++) { if (l != L_ref) { uint32_t idx = SRSLTE_RE_IDX(q->cell.nof_prb, l+slot*SRSLTE_CP_NSYMB(q->cell.cp), grant->n_prb_tilde[slot]*SRSLTE_NRE); if (advance_input) { out_ptr = &output[idx]; } else { in_ptr = &input[idx]; } memcpy(out_ptr, in_ptr, grant->L_prb * SRSLTE_NRE * sizeof(cf_t)); if (advance_input) { in_ptr += grant->L_prb*SRSLTE_NRE; } else { out_ptr += grant->L_prb*SRSLTE_NRE; } } } } if (advance_input) { return in_ptr - input; } else { return out_ptr - output; } } int pusch_put(srslte_pusch_t *q, srslte_ra_ul_grant_t *grant, cf_t *input, cf_t *output) { return pusch_cp(q, grant, input, output, true); } int pusch_get(srslte_pusch_t *q, srslte_ra_ul_grant_t *grant, cf_t *input, cf_t *output) { return pusch_cp(q, grant, input, output, false); } /** Initializes the PDCCH transmitter and receiver */ int pusch_init(srslte_pusch_t *q, uint32_t max_prb, bool is_ue) { int ret = SRSLTE_ERROR_INVALID_INPUTS; int i; if (q != NULL) { bzero(q, sizeof(srslte_pusch_t)); ret = SRSLTE_ERROR; q->max_re = max_prb * MAX_PUSCH_RE(SRSLTE_CP_NORM); INFO("Init PUSCH: %d PRBs\n", max_prb); 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]); } q->is_ue = is_ue; q->users = calloc(sizeof(srslte_pusch_user_t*), q->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; } srslte_sch_init(&q->ul_sch); if (srslte_dft_precoding_init(&q->dft_precoding, max_prb, is_ue)) { fprintf(stderr, "Error initiating DFT transform precoding\n"); goto clean; } // Allocate int16 for reception (LLRs). Buffer casted to uint8_t for transmission q->q = srslte_vec_malloc(sizeof(int16_t) * q->max_re * srslte_mod_bits_x_symbol(SRSLTE_MOD_64QAM)); if (!q->q) { goto clean; } // Allocate int16 for reception (LLRs). Buffer casted to uint8_t for transmission q->g = srslte_vec_malloc(sizeof(int16_t) * q->max_re * srslte_mod_bits_x_symbol(SRSLTE_MOD_64QAM)); if (!q->g) { goto clean; } q->d = srslte_vec_malloc(sizeof(cf_t) * q->max_re); if (!q->d) { goto clean; } if (!q->is_ue) { q->ce = srslte_vec_malloc(sizeof(cf_t) * q->max_re); if (!q->ce) { goto clean; } } q->z = srslte_vec_malloc(sizeof(cf_t) * q->max_re); if (!q->z) { goto clean; } ret = SRSLTE_SUCCESS; } clean: if (ret == SRSLTE_ERROR) { srslte_pusch_free(q); } return ret; } int srslte_pusch_init_ue(srslte_pusch_t *q, uint32_t max_prb) { return pusch_init(q, max_prb, true); } int srslte_pusch_init_enb(srslte_pusch_t *q, uint32_t max_prb) { return pusch_init(q, max_prb, false); } void srslte_pusch_free(srslte_pusch_t *q) { int i; if (q->q) { free(q->q); } if (q->d) { free(q->d); } if (q->g) { free(q->g); } if (q->ce) { free(q->ce); } if (q->z) { free(q->z); } srslte_dft_precoding_free(&q->dft_precoding); if (q->users) { if (q->is_ue) { srslte_pusch_free_rnti(q, 0); } else { for (int rnti=0;rnti<=SRSLTE_SIRNTI;rnti++) { srslte_pusch_free_rnti(q, rnti); } } free(q->users); } srslte_sequence_free(&q->seq_type2_fo); srslte_sequence_free(&q->tmp_seq); for (i = 0; i < 4; i++) { srslte_modem_table_free(&q->mod[i]); } srslte_sch_free(&q->ul_sch); bzero(q, sizeof(srslte_pusch_t)); } int srslte_pusch_set_cell(srslte_pusch_t *q, srslte_cell_t cell) { int ret = SRSLTE_ERROR_INVALID_INPUTS; if (q != NULL && srslte_cell_isvalid(&cell)) { q->max_re = cell.nof_prb * MAX_PUSCH_RE(q->cell.cp); INFO("PUSCH: Cell config PCI=%d, %d ports %d PRBs, max_symbols: %d\n", q->cell.id, q->cell.nof_ports, q->cell.nof_prb, q->max_re); if (q->cell.id != cell.id || q->cell.nof_prb == 0) { memcpy(&q->cell, &cell, sizeof(srslte_cell_t)); /* Precompute sequence for type2 frequency hopping */ if (srslte_sequence_LTE_pr(&q->seq_type2_fo, 210, q->cell.id)) { fprintf(stderr, "Error initiating type2 frequency hopping sequence\n"); return SRSLTE_ERROR; } } ret = SRSLTE_SUCCESS; } return ret; } /* Configures the structure srslte_pusch_cfg_t from the UL DCI allocation dci_msg. * If dci_msg is NULL, the grant is assumed to be already stored in cfg->grant */ int srslte_pusch_cfg(srslte_pusch_t *q, srslte_pusch_cfg_t *cfg, srslte_ra_ul_grant_t *grant, srslte_uci_cfg_t *uci_cfg, srslte_pusch_hopping_cfg_t *hopping_cfg, srslte_refsignal_srs_cfg_t *srs_cfg, uint32_t tti, uint32_t rv_idx, uint32_t current_tx_nb) { if (q && cfg && grant) { memcpy(&cfg->grant, grant, sizeof(srslte_ra_ul_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; } /* Compute PUSCH frequency hopping */ if (hopping_cfg) { compute_freq_hopping(q, &cfg->grant, hopping_cfg, tti%10, current_tx_nb); } else { cfg->grant.n_prb_tilde[0] = cfg->grant.n_prb[0]; cfg->grant.n_prb_tilde[1] = cfg->grant.n_prb[1]; } if (srs_cfg) { q->shortened = false; if (srs_cfg->configured) { // If UE-specific SRS is configured, PUSCH is shortened every time UE transmits SRS even if overlaping in the same RB or not if (srslte_refsignal_srs_send_cs(srs_cfg->subframe_config, tti%10) == 1 && srslte_refsignal_srs_send_ue(srs_cfg->I_srs, tti) == 1) { q->shortened = true; /* If RBs are contiguous, PUSCH is not shortened */ uint32_t k0_srs = srslte_refsignal_srs_rb_start_cs(srs_cfg->bw_cfg, q->cell.nof_prb); uint32_t nrb_srs = srslte_refsignal_srs_rb_L_cs(srs_cfg->bw_cfg, q->cell.nof_prb); for (uint32_t ns=0;ns<2 && q->shortened;ns++) { if (cfg->grant.n_prb_tilde[ns] == k0_srs + nrb_srs || // If PUSCH is contiguous on the right-hand side of SRS cfg->grant.n_prb_tilde[ns] + cfg->grant.L_prb == k0_srs) // If SRS is contiguous on the left-hand side of PUSCH { q->shortened = false; } } } // If not coincides with UE transmission. PUSCH shall be shortened if cell-specific SRS transmission RB //coincides with PUSCH allocated RB if (!q->shortened) { if (srslte_refsignal_srs_send_cs(srs_cfg->subframe_config, tti%10) == 1) { uint32_t k0_srs = srslte_refsignal_srs_rb_start_cs(srs_cfg->bw_cfg, q->cell.nof_prb); uint32_t nrb_srs = srslte_refsignal_srs_rb_L_cs(srs_cfg->bw_cfg, q->cell.nof_prb); for (uint32_t ns=0;ns<2 && !q->shortened;ns++) { if ((cfg->grant.n_prb_tilde[ns] >= k0_srs && cfg->grant.n_prb_tilde[ns] < k0_srs + nrb_srs) || (cfg->grant.n_prb_tilde[ns] + cfg->grant.L_prb >= k0_srs && cfg->grant.n_prb_tilde[ns] + cfg->grant.L_prb < k0_srs + nrb_srs) || (cfg->grant.n_prb_tilde[ns] <= k0_srs && cfg->grant.n_prb_tilde[ns] + cfg->grant.L_prb >= k0_srs + nrb_srs)) { q->shortened = true; } } } } } } /* Compute final number of bits and RE */ srslte_ra_ul_grant_to_nbits(&cfg->grant, q->cell.cp, q->shortened?1:0, &cfg->nbits); cfg->sf_idx = tti%10; cfg->tti = tti; cfg->rv = rv_idx; cfg->cp = q->cell.cp; // Save UCI configuration if (uci_cfg) { memcpy(&cfg->uci_cfg, uci_cfg, sizeof(srslte_uci_cfg_t)); } return SRSLTE_SUCCESS; } else { return SRSLTE_ERROR_INVALID_INPUTS; } } /* Precalculate the PUSCH 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() functions */ int srslte_pusch_set_rnti(srslte_pusch_t *q, uint16_t rnti) { uint32_t i; uint32_t rnti_idx = q->is_ue?0:rnti; if (!q->users[rnti_idx] || q->is_ue) { if (!q->users[rnti_idx]) { q->users[rnti_idx] = calloc(1, sizeof(srslte_pusch_user_t)); if (!q->users[rnti_idx]) { perror("calloc"); return -1; } } for (i = 0; i < SRSLTE_NSUBFRAMES_X_FRAME; i++) { if (srslte_sequence_pusch(&q->users[rnti_idx]->seq[i], rnti, 2 * i, q->cell.id, q->max_re * srslte_mod_bits_x_symbol(SRSLTE_MOD_64QAM))) { fprintf(stderr, "Error initializing PUSCH scrambling sequence\n"); srslte_pusch_free_rnti(q, rnti); return SRSLTE_ERROR; } } q->ue_rnti = rnti; q->users[rnti_idx]->cell_id = q->cell.id; q->users[rnti_idx]->sequence_generated = true; } else { fprintf(stderr, "Error generating PUSCH sequence: rnti=0x%x already generated\n", rnti); } return SRSLTE_SUCCESS; } void srslte_pusch_free_rnti(srslte_pusch_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; q->ue_rnti = 0; } } static srslte_sequence_t *get_user_sequence(srslte_pusch_t *q, uint16_t rnti, uint32_t sf_idx, uint32_t len) { uint32_t rnti_idx = q->is_ue?0:rnti; // The scrambling sequence is pregenerated for all RNTIs in the eNodeB but only for C-RNTI in the UE if (q->users[rnti_idx] && q->users[rnti_idx]->sequence_generated && q->users[rnti_idx]->cell_id == q->cell.id && q->ue_rnti == rnti && ((rnti >= SRSLTE_CRNTI_START && rnti < SRSLTE_CRNTI_END) || !q->is_ue)) { return &q->users[rnti_idx]->seq[sf_idx]; } else { srslte_sequence_pusch(&q->tmp_seq, rnti, 2 * sf_idx, q->cell.id, len); return &q->tmp_seq; } } /** Converts the PUSCH data bits to symbols mapped to the slot ready for transmission */ int srslte_pusch_encode(srslte_pusch_t *q, srslte_pusch_cfg_t *cfg, srslte_softbuffer_tx_t *softbuffer, uint8_t *data, srslte_uci_data_t uci_data, uint16_t rnti, cf_t *sf_symbols) { int ret = SRSLTE_ERROR_INVALID_INPUTS; if (q != NULL && cfg != NULL) { if (cfg->nbits.nof_re > q->max_re) { fprintf(stderr, "Error too many RE per subframe (%d). PUSCH 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 PUSCH SF: %d, Mod %s, RNTI: %d, TBS: %d, NofRE: %d, NofSymbols=%d, NofBitsE: %d, rv_idx: %d\n", cfg->sf_idx, srslte_mod_string(cfg->grant.mcs.mod), rnti, cfg->grant.mcs.tbs, cfg->nbits.nof_re, cfg->nbits.nof_symb, cfg->nbits.nof_bits, cfg->rv); bzero(q->q, cfg->nbits.nof_bits); if (srslte_ulsch_uci_encode(&q->ul_sch, cfg, softbuffer, data, uci_data, q->g, q->q)) { 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); // Run scrambling srslte_scrambling_bytes(seq, (uint8_t*) q->q, cfg->nbits.nof_bits); // Correct UCI placeholder/repetition bits uint8_t *d = q->q; for (int i = 0; i < q->ul_sch.nof_ri_ack_bits; i++) { if (q->ul_sch.ack_ri_bits[i].type == UCI_BIT_PLACEHOLDER) { d[q->ul_sch.ack_ri_bits[i].position/8] |= (1<<(7-q->ul_sch.ack_ri_bits[i].position%8)); } else if (q->ul_sch.ack_ri_bits[i].type == UCI_BIT_REPETITION) { if (q->ul_sch.ack_ri_bits[i].position > 1) { uint32_t p=q->ul_sch.ack_ri_bits[i].position; uint8_t bit = d[(p-1)/8] & (1<<(7-(p-1)%8)); if (bit) { d[p/8] |= 1<<(7-p%8); } else { d[p/8] &= ~(1<<(7-p%8)); } } } } // Bit mapping srslte_mod_modulate_bytes(&q->mod[cfg->grant.mcs.mod], (uint8_t*) q->q, q->d, cfg->nbits.nof_bits); // DFT precoding srslte_dft_precoding(&q->dft_precoding, q->d, q->z, cfg->grant.L_prb, cfg->nbits.nof_symb); // Mapping to resource elements pusch_put(q, &cfg->grant, q->z, sf_symbols); ret = SRSLTE_SUCCESS; } return ret; } /** Decodes the PUSCH from the received symbols */ int srslte_pusch_decode(srslte_pusch_t *q, srslte_pusch_cfg_t *cfg, srslte_softbuffer_rx_t *softbuffer, cf_t *sf_symbols, cf_t *ce, float noise_estimate, uint16_t rnti, uint8_t *data, srslte_cqi_value_t *cqi_value, srslte_uci_data_t *uci_data) { int ret = SRSLTE_ERROR_INVALID_INPUTS; uint32_t n; if (q != NULL && sf_symbols != NULL && data != NULL && cfg != NULL) { INFO("Decoding PUSCH SF: %d, Mod %s, NofBits: %d, NofRE: %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_symb, cfg->nbits.nof_bits, cfg->rv); /* extract symbols */ n = pusch_get(q, &cfg->grant, sf_symbols, q->d); 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 */ n = pusch_get(q, &cfg->grant, ce, q->ce); if (n != cfg->nbits.nof_re) { fprintf(stderr, "Error expecting %d symbols but got %d\n", cfg->nbits.nof_re, n); return SRSLTE_ERROR; } // Equalization srslte_predecoding_single(q->d, q->ce, q->z, NULL, cfg->nbits.nof_re, 1.0f, noise_estimate); // DFT predecoding srslte_dft_precoding(&q->dft_precoding, q->z, q->d, cfg->grant.L_prb, cfg->nbits.nof_symb); // Soft demodulation srslte_demod_soft_demodulate_s(cfg->grant.mcs.mod, q->d, q->q, 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); // Set CQI len assuming RI = 1 (3GPP 36.212 Clause 5.2.4.1. Uplink control information on PUSCH without UL-SCH data) if (cqi_value) { if (cqi_value->type == SRSLTE_CQI_TYPE_SUBBAND_HL && cqi_value->subband_hl.ri_present) { cqi_value->subband_hl.rank_is_not_one = false; uci_data->uci_ri_len = (q->cell.nof_ports == 4) ? 2 : 1; } uci_data->uci_cqi_len = (uint32_t) srslte_cqi_size(cqi_value); } // Decode RI/HARQ bits before descrambling if (srslte_ulsch_uci_decode_ri_ack(&q->ul_sch, cfg, softbuffer, q->q, seq->c, uci_data)) { fprintf(stderr, "Error decoding RI/HARQ bits\n"); return SRSLTE_ERROR; } // Set CQI len with corresponding RI if (cqi_value) { if (cqi_value->type == SRSLTE_CQI_TYPE_SUBBAND_HL) { cqi_value->subband_hl.rank_is_not_one = (uci_data->uci_ri != 0); } uci_data->uci_cqi_len = (uint32_t) srslte_cqi_size(cqi_value); } // Descrambling srslte_scrambling_s_offset(seq, q->q, 0, cfg->nbits.nof_bits); // Decode ret = srslte_ulsch_uci_decode(&q->ul_sch, cfg, softbuffer, q->q, q->g, data, uci_data); // Unpack CQI value if available if (cqi_value) { srslte_cqi_value_unpack(uci_data->uci_cqi, cqi_value); } } return ret; } uint32_t srslte_pusch_last_noi(srslte_pusch_t *q) { return q->ul_sch.nof_iterations; }