/** * * \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 "srslte/phch/pdsch.h" #include "srslte/phch/pusch.h" #include "srslte/phch/sch.h" #include "srslte/phch/uci.h" #include "srslte/common/phy_common.h" #include "srslte/utils/bit.h" #include "srslte/utils/debug.h" #include "srslte/utils/vector.h" #define SRSLTE_PDSCH_MAX_TDEC_ITERS 4 /* 36.213 Table 8.6.3-1: Mapping of HARQ-ACK offset values and the index signalled by higher layers */ float beta_harq_offset[16] = {2.0, 2.5, 3.125, 4.0, 5.0, 6.250, 8.0, 10.0, 12.625, 15.875, 20.0, 31.0, 50.0, 80.0, 126.0, -1.0}; /* 36.213 Table 8.6.3-2: Mapping of RI offset values and the index signalled by higher layers */ float beta_ri_offset[16] = {1.25, 1.625, 2.0, 2.5, 3.125, 4.0, 5.0, 6.25, 8.0, 10.0, 12.625, 15.875, 20.0, -1.0, -1.0, -1.0}; /* 36.213 Table 8.6.3-3: Mapping of CQI offset values and the index signalled by higher layers */ float beta_cqi_offset[16] = {-1.0, -1.0, 1.125, 1.25, 1.375, 1.625, 1.750, 2.0, 2.25, 2.5, 2.875, 3.125, 3.5, 4.0, 5.0, 6.25}; float srslte_sch_beta_cqi(uint32_t I_cqi) { if (I_cqi < 16) { return beta_cqi_offset[I_cqi]; } else { return 0; } } uint32_t srslte_sch_find_Ioffset_ack(float beta) { for (int i=0;i<16;i++) { if (beta_harq_offset[i] >= beta) { return i; } } return 0; } uint32_t srslte_sch_find_Ioffset_ri(float beta) { for (int i=0;i<16;i++) { if (beta_ri_offset[i] >= beta) { return i; } } return 0; } uint32_t srslte_sch_find_Ioffset_cqi(float beta) { for (int i=0;i<16;i++) { if (beta_cqi_offset[i] >= beta) { return i; } } return 0; } int srslte_sch_init(srslte_sch_t *q) { int ret = SRSLTE_ERROR_INVALID_INPUTS; if (q) { bzero(q, sizeof(srslte_sch_t)); if (srslte_crc_init(&q->crc_tb, SRSLTE_LTE_CRC24A, 24)) { fprintf(stderr, "Error initiating CRC\n"); goto clean; } if (srslte_crc_init(&q->crc_cb, SRSLTE_LTE_CRC24B, 24)) { fprintf(stderr, "Error initiating CRC\n"); goto clean; } if (srslte_tcod_init(&q->encoder, SRSLTE_TCOD_MAX_LEN_CB)) { fprintf(stderr, "Error initiating Turbo Coder\n"); goto clean; } if (srslte_tdec_init(&q->decoder, SRSLTE_TCOD_MAX_LEN_CB)) { fprintf(stderr, "Error initiating Turbo Decoder\n"); goto clean; } q->max_iterations = SRSLTE_PDSCH_MAX_TDEC_ITERS; srslte_rm_turbo_gentables(); // Allocate int16 for reception (LLRs) q->cb_in = srslte_vec_malloc(sizeof(uint8_t) * (SRSLTE_TCOD_MAX_LEN_CB+8)/8); if (!q->cb_in) { goto clean; } q->parity_bits = srslte_vec_malloc(sizeof(uint8_t) * (3 * SRSLTE_TCOD_MAX_LEN_CB + 16) / 8); if (!q->parity_bits) { goto clean; } q->temp_g_bits = srslte_vec_malloc(sizeof(uint8_t)*SRSLTE_MAX_PRB*12*12*12); if (!q->temp_g_bits) { goto clean; } bzero(q->temp_g_bits, SRSLTE_MAX_PRB*12*12*12); q->ul_interleaver = srslte_vec_malloc(sizeof(uint16_t)*SRSLTE_MAX_PRB*12*12*12); if (!q->ul_interleaver) { goto clean; } if (srslte_uci_cqi_init(&q->uci_cqi)) { goto clean; } ret = SRSLTE_SUCCESS; } clean: if (ret == SRSLTE_ERROR) { srslte_sch_free(q); } return ret; } void srslte_sch_free(srslte_sch_t *q) { if (q->cb_in) { free(q->cb_in); } if (q->parity_bits) { free(q->parity_bits); } if (q->temp_g_bits) { free(q->temp_g_bits); } if (q->ul_interleaver) { free(q->ul_interleaver); } srslte_tdec_free(&q->decoder); srslte_tcod_free(&q->encoder); srslte_uci_cqi_free(&q->uci_cqi); bzero(q, sizeof(srslte_sch_t)); } void srslte_sch_set_max_noi(srslte_sch_t *q, uint32_t max_iterations) { q->max_iterations = max_iterations; } float srslte_sch_average_noi(srslte_sch_t *q) { return q->average_nof_iterations; } uint32_t srslte_sch_last_noi(srslte_sch_t *q) { return q->nof_iterations; } /* Encode a transport block according to 36.212 5.3.2 * */ static int encode_tb_off(srslte_sch_t *q, srslte_softbuffer_tx_t *softbuffer, srslte_cbsegm_t *cb_segm, uint32_t Qm, uint32_t rv, uint32_t nof_e_bits, uint8_t *data, uint8_t *e_bits, uint32_t w_offset) { uint8_t parity[3] = {0, 0, 0}; uint32_t par; uint32_t i; uint32_t cb_len=0, rp=0, wp=0, rlen=0, n_e=0; int ret = SRSLTE_ERROR_INVALID_INPUTS; if (q != NULL && e_bits != NULL && cb_segm != NULL && softbuffer != NULL) { if (cb_segm->F) { fprintf(stderr, "Error filler bits are not supported. Use standard TBS\n"); return SRSLTE_ERROR; } if (cb_segm->C > softbuffer->max_cb) { fprintf(stderr, "Error number of CB (%d) exceeds soft buffer size (%d CBs)\n", cb_segm->C, softbuffer->max_cb); return -1; } uint32_t Gp = nof_e_bits / Qm; uint32_t gamma = Gp; if (cb_segm->C > 0) { gamma = Gp%cb_segm->C; } if (data) { /* Compute transport block CRC */ par = srslte_crc_checksum_byte(&q->crc_tb, data, cb_segm->tbs); /* parity bits will be appended later */ parity[0] = (par&(0xff<<16))>>16; parity[1] = (par&(0xff<<8))>>8; parity[2] = par&0xff; } wp = 0; rp = 0; for (i = 0; i < cb_segm->C; i++) { uint32_t cblen_idx; /* Get read lengths */ if (i < cb_segm->C2) { cb_len = cb_segm->K2; cblen_idx = cb_segm->K2_idx; } else { cb_len = cb_segm->K1; cblen_idx = cb_segm->K1_idx; } if (cb_segm->C > 1) { rlen = cb_len - 24; } else { rlen = cb_len; } if (i <= cb_segm->C - gamma - 1) { n_e = Qm * (Gp/cb_segm->C); } else { n_e = Qm * ((uint32_t) ceilf((float) Gp/cb_segm->C)); } INFO("CB#%d: cb_len: %d, rlen: %d, wp: %d, rp: %d, E: %d\n", i, cb_len, rlen, wp, rp, n_e); if (data) { /* Copy data to another buffer, making space for the Codeblock CRC */ if (i < cb_segm->C - 1) { // Copy data memcpy(q->cb_in, &data[rp/8], rlen * sizeof(uint8_t)/8); } else { INFO("Last CB, appending parity: %d from %d and 24 to %d\n", rlen - 24, rp, rlen - 24); /* Append Transport Block parity bits to the last CB */ memcpy(q->cb_in, &data[rp/8], (rlen - 24) * sizeof(uint8_t)/8); memcpy(&q->cb_in[(rlen - 24)/8], parity, 3 * sizeof(uint8_t)); } /* Attach Codeblock CRC */ if (cb_segm->C > 1) { srslte_crc_attach_byte(&q->crc_cb, q->cb_in, rlen); } /* Turbo Encoding */ srslte_tcod_encode_lut(&q->encoder, q->cb_in, q->parity_bits, cblen_idx); } DEBUG("RM cblen_idx=%d, n_e=%d, wp=%d, nof_e_bits=%d\n",cblen_idx, n_e, wp, nof_e_bits); /* Rate matching */ if (srslte_rm_turbo_tx_lut(softbuffer->buffer_b[i], q->cb_in, q->parity_bits, &e_bits[(wp+w_offset)/8], cblen_idx, n_e, (wp+w_offset)%8, rv)) { fprintf(stderr, "Error in rate matching\n"); return SRSLTE_ERROR; } /* Set read/write pointers */ rp += rlen; wp += n_e; } INFO("END CB#%d: wp: %d, rp: %d\n", i, wp, rp); ret = SRSLTE_SUCCESS; } return ret; } static int encode_tb(srslte_sch_t *q, srslte_softbuffer_tx_t *soft_buffer, srslte_cbsegm_t *cb_segm, uint32_t Qm, uint32_t rv, uint32_t nof_e_bits, uint8_t *data, uint8_t *e_bits) { return encode_tb_off(q, soft_buffer, cb_segm, Qm, rv, nof_e_bits, data, e_bits, 0); } /* Decode a transport block according to 36.212 5.3.2 * */ static int decode_tb(srslte_sch_t *q, srslte_softbuffer_rx_t *softbuffer, srslte_cbsegm_t *cb_segm, uint32_t Qm, uint32_t rv, uint32_t nof_e_bits, int16_t *e_bits, uint8_t *data) { uint8_t parity[3] = {0, 0, 0}; uint32_t par_rx, par_tx; uint32_t i; uint32_t cb_len, rp, wp, rlen, n_e; if (q != NULL && data != NULL && softbuffer != NULL && e_bits != NULL && cb_segm != NULL) { if (cb_segm->tbs == 0 || cb_segm->C == 0) { return SRSLTE_SUCCESS; } rp = 0; rp = 0; wp = 0; uint32_t Gp = nof_e_bits / Qm; uint32_t gamma=Gp; if (cb_segm->F) { fprintf(stderr, "Error filler bits are not supported. Use standard TBS\n"); return SRSLTE_ERROR; } if (cb_segm->C > softbuffer->max_cb) { fprintf(stderr, "Error number of CB (%d) exceeds soft buffer size (%d CBs)\n", cb_segm->C, softbuffer->max_cb); return -1; } if (cb_segm->C>0) { gamma = Gp%cb_segm->C; } bool early_stop = true; for (i = 0; i < cb_segm->C && early_stop; i++) { /* Get read/write lengths */ uint32_t cblen_idx; if (i < cb_segm->C2) { cb_len = cb_segm->K2; cblen_idx = cb_segm->K2_idx; } else { cb_len = cb_segm->K1; cblen_idx = cb_segm->K1_idx; } if (cb_segm->C == 1) { rlen = cb_len; } else { rlen = cb_len - 24; } if (i <= cb_segm->C - gamma - 1) { n_e = Qm * (Gp/cb_segm->C); } else { n_e = Qm * ((uint32_t) ceilf((float) Gp/cb_segm->C)); } /* Rate Unmatching */ if (srslte_rm_turbo_rx_lut(&e_bits[rp], softbuffer->buffer_f[i], n_e, cblen_idx, rv)) { fprintf(stderr, "Error in rate matching\n"); return SRSLTE_ERROR; } if (SRSLTE_VERBOSE_ISDEBUG()) { char tmpstr[64]; snprintf(tmpstr,64,"rmout_%d.dat",i); DEBUG("SAVED FILE %s: Encoded turbo code block %d\n", tmpstr, i); srslte_vec_save_file(tmpstr, softbuffer->buffer_f[i], (3*cb_len+12)*sizeof(int16_t)); } /* Turbo Decoding with CRC-based early stopping */ q->nof_iterations = 0; uint32_t len_crc; srslte_crc_t *crc_ptr; early_stop = false; srslte_tdec_reset(&q->decoder, cb_len); do { srslte_tdec_iteration(&q->decoder, softbuffer->buffer_f[i], cb_len); q->nof_iterations++; if (cb_segm->C > 1) { len_crc = cb_len; crc_ptr = &q->crc_cb; } else { len_crc = cb_segm->tbs+24; crc_ptr = &q->crc_tb; } srslte_tdec_decision_byte(&q->decoder, q->cb_in, cb_len); /* Check Codeblock CRC and stop early if correct */ if (!srslte_crc_checksum_byte(crc_ptr, q->cb_in, len_crc)) { early_stop = true; } } while (q->nof_iterations < q->max_iterations && !early_stop); q->average_nof_iterations = SRSLTE_VEC_EMA((float) q->nof_iterations, q->average_nof_iterations, 0.2); INFO("CB#%d: cb_len: %d, rlen: %d, wp: %d, rp: %d, E: %d, n_iters=%d\n", i, cb_len, rlen, wp, rp, n_e, q->nof_iterations); // If CB CRC is not correct, early_stop will be false and wont continue with rest of CBs /* Copy data to another buffer, removing the Codeblock CRC */ if (i < cb_segm->C - 1) { memcpy(&data[wp/8], q->cb_in, rlen/8 * sizeof(uint8_t)); } else { /* Append Transport Block parity bits to the last CB */ memcpy(&data[wp/8], q->cb_in, (rlen - 24)/8 * sizeof(uint8_t)); memcpy(parity, &q->cb_in[(rlen - 24)/8], 3 * sizeof(uint8_t)); } if (SRSLTE_VERBOSE_ISDEBUG()) { early_stop = true; } /* Set read/write pointers */ wp += rlen; rp += n_e; } if (!early_stop) { INFO("CB %d failed. TB is erroneous.\n",i-1); return SRSLTE_ERROR; } else { INFO("END CB#%d: wp: %d, rp: %d\n", i, wp, rp); // Compute transport block CRC par_rx = srslte_crc_checksum_byte(&q->crc_tb, data, cb_segm->tbs); // check parity bits par_tx = ((uint32_t) parity[0])<<16 | ((uint32_t) parity[1])<<8 | ((uint32_t) parity[2]); if (!par_rx) { INFO("Warning: Received all-zero transport block\n\n", 0); } if (par_rx == par_tx && par_rx) { INFO("TB decoded OK\n",i); return SRSLTE_SUCCESS; } else { INFO("Error in TB parity: par_tx=0x%x, par_rx=0x%x\n", par_tx, par_rx); return SRSLTE_ERROR; } } } else { return SRSLTE_ERROR_INVALID_INPUTS; } } int srslte_dlsch_decode(srslte_sch_t *q, srslte_pdsch_cfg_t *cfg, srslte_softbuffer_rx_t *softbuffer, int16_t *e_bits, uint8_t *data) { return decode_tb(q, softbuffer, &cfg->cb_segm, cfg->grant.Qm, cfg->rv, cfg->nbits.nof_bits, e_bits, data); } int srslte_dlsch_encode(srslte_sch_t *q, srslte_pdsch_cfg_t *cfg, srslte_softbuffer_tx_t *softbuffer, uint8_t *data, uint8_t *e_bits) { return encode_tb(q, softbuffer, &cfg->cb_segm, cfg->grant.Qm, cfg->rv, cfg->nbits.nof_bits, data, e_bits); } /* Compute the interleaving function on-the-fly, because it depends on number of RI bits * Profiling show that the computation of this matrix is neglegible. */ static void ulsch_interleave_gen(uint32_t H_prime_total, uint32_t N_pusch_symbs, uint32_t Qm, uint8_t *ri_present, uint16_t *interleaver_lut) { uint32_t rows = H_prime_total/N_pusch_symbs; uint32_t cols = N_pusch_symbs; uint32_t idx = 0; for(uint32_t j=0; j 0) { for (uint32_t i=0;i 0) { for (uint32_t i=0;i 0) { for (uint32_t i=0;i 0) { for (uint32_t i=0;inbits.nof_bits; uint32_t Qm = cfg->grant.Qm; cfg->last_O_cqi = uci_data->uci_cqi_len; // Deinterleave and decode HARQ bits if (uci_data->uci_ack_len > 0) { float beta = beta_harq_offset[cfg->uci_cfg.I_offset_ack]; if (cfg->cb_segm.tbs == 0) { beta /= beta_cqi_offset[cfg->uci_cfg.I_offset_cqi]; } ret = srslte_uci_decode_ack(cfg, q_bits, c_seq, beta, nb_q/Qm, uci_data->uci_cqi_len, q->ack_ri_bits, &uci_data->uci_ack); if (ret < 0) { return ret; } Q_prime_ack = (uint32_t) ret; // Set zeros to HARQ bits for (uint32_t i=0;iack_ri_bits[i].position] = 0; } } // Deinterleave and decode RI bits if (uci_data->uci_ri_len > 0) { float beta = beta_ri_offset[cfg->uci_cfg.I_offset_ri]; if (cfg->cb_segm.tbs == 0) { beta /= beta_cqi_offset[cfg->uci_cfg.I_offset_cqi]; } ret = srslte_uci_decode_ri(cfg, q_bits, c_seq, beta, nb_q/Qm, uci_data->uci_cqi_len, q->ack_ri_bits, &uci_data->uci_ri); if (ret < 0) { return ret; } Q_prime_ri = (uint32_t) ret; } q->nof_ri_ack_bits = Q_prime_ri; return SRSLTE_SUCCESS; } int srslte_ulsch_uci_decode(srslte_sch_t *q, srslte_pusch_cfg_t *cfg, srslte_softbuffer_rx_t *softbuffer, int16_t *q_bits, int16_t *g_bits, uint8_t *data, srslte_uci_data_t *uci_data) { int ret = 0; uint32_t Q_prime_ri = q->nof_ri_ack_bits; uint32_t Q_prime_cqi = 0; uint32_t e_offset = 0; uint32_t nb_q = cfg->nbits.nof_bits; uint32_t Qm = cfg->grant.Qm; // Deinterleave data and CQI in ULSCH ulsch_deinterleave(q_bits, Qm, nb_q/Qm, cfg->nbits.nof_symb, g_bits, q->ack_ri_bits, Q_prime_ri*Qm, q->temp_g_bits, q->ul_interleaver); // Decode CQI (multiplexed at the front of ULSCH) if (uci_data->uci_cqi_len > 0) { ret = srslte_uci_decode_cqi_pusch(&q->uci_cqi, cfg, g_bits, beta_cqi_offset[cfg->uci_cfg.I_offset_cqi], Q_prime_ri, uci_data->uci_cqi_len, uci_data->uci_cqi, &uci_data->cqi_ack); if (ret < 0) { return ret; } Q_prime_cqi = (uint32_t) ret; } e_offset += Q_prime_cqi*Qm; // Decode ULSCH if (cfg->cb_segm.tbs > 0) { uint32_t G = nb_q/Qm - Q_prime_ri - Q_prime_cqi; ret = decode_tb(q, softbuffer, &cfg->cb_segm, Qm, cfg->rv, G*Qm, &g_bits[e_offset], data); if (ret) { return ret; } } return SRSLTE_SUCCESS; } int srslte_ulsch_encode(srslte_sch_t *q, srslte_pusch_cfg_t *cfg, srslte_softbuffer_tx_t *softbuffer, uint8_t *data, uint8_t *g_bits, uint8_t *q_bits) { srslte_uci_data_t uci_data; bzero(&uci_data, sizeof(srslte_uci_data_t)); return srslte_ulsch_uci_encode(q, cfg, softbuffer, data, uci_data, g_bits, q_bits); } int srslte_ulsch_uci_encode(srslte_sch_t *q, srslte_pusch_cfg_t *cfg, srslte_softbuffer_tx_t *softbuffer, uint8_t *data, srslte_uci_data_t uci_data, uint8_t *g_bits, uint8_t *q_bits) { int ret; uint32_t e_offset = 0; uint32_t Q_prime_cqi = 0; uint32_t Q_prime_ack = 0; uint32_t Q_prime_ri = 0; uint32_t nb_q = cfg->nbits.nof_bits; uint32_t Qm = cfg->grant.Qm; // Encode RI if (uci_data.uci_ri_len > 0) { float beta = beta_ri_offset[cfg->uci_cfg.I_offset_ri]; if (cfg->cb_segm.tbs == 0) { beta /= beta_cqi_offset[cfg->uci_cfg.I_offset_cqi]; } ret = srslte_uci_encode_ri(cfg, uci_data.uci_ri, uci_data.uci_cqi_len, beta, nb_q/Qm, q->ack_ri_bits); if (ret < 0) { return ret; } Q_prime_ri = (uint32_t) ret; } // Encode CQI cfg->last_O_cqi = uci_data.uci_cqi_len; if (uci_data.uci_cqi_len > 0) { ret = srslte_uci_encode_cqi_pusch(&q->uci_cqi, cfg, uci_data.uci_cqi, uci_data.uci_cqi_len, beta_cqi_offset[cfg->uci_cfg.I_offset_cqi], Q_prime_ri, q->temp_g_bits); if (ret < 0) { return ret; } Q_prime_cqi = (uint32_t) ret; srslte_bit_pack_vector(q->temp_g_bits, g_bits, Q_prime_cqi*Qm); // Reset the buffer because will be reused in ulsch_interleave bzero(q->temp_g_bits, Q_prime_cqi*Qm); } e_offset += Q_prime_cqi*Qm; // Encode UL-SCH if (cfg->cb_segm.tbs > 0) { uint32_t G = nb_q/Qm - Q_prime_ri - Q_prime_cqi; ret = encode_tb_off(q, softbuffer, &cfg->cb_segm, Qm, cfg->rv, G*Qm, data, &g_bits[e_offset/8], e_offset%8); if (ret) { return ret; } } // Interleave UL-SCH (and RI and CQI) ulsch_interleave(g_bits, Qm, nb_q/Qm, cfg->nbits.nof_symb, q_bits, q->ack_ri_bits, Q_prime_ri*Qm, q->temp_g_bits, q->ul_interleaver); // Encode (and interleave) ACK if (uci_data.uci_ack_len > 0) { float beta = beta_harq_offset[cfg->uci_cfg.I_offset_ack]; if (cfg->cb_segm.tbs == 0) { beta /= beta_cqi_offset[cfg->uci_cfg.I_offset_cqi]; } ret = srslte_uci_encode_ack(cfg, uci_data.uci_ack, uci_data.uci_cqi_len, beta, nb_q/Qm, &q->ack_ri_bits[Q_prime_ri*Qm]); if (ret < 0) { return ret; } Q_prime_ack = (uint32_t) ret; } q->nof_ri_ack_bits = (Q_prime_ack+Q_prime_ri)*Qm; for (uint32_t i=0;inof_ri_ack_bits;i++) { uint32_t p = q->ack_ri_bits[i].position; if (p < nb_q) { if (q->ack_ri_bits[i].type == UCI_BIT_1) { q_bits[p/8] |= (1<<(7-p%8)); } else { q_bits[p/8] &= ~(1<<(7-p%8)); } } else { fprintf(stderr, "Invalid RI/ACK bit position %d. Max bits=%d\n", p, nb_q); } } INFO("Q_prime_ack=%d, Q_prime_cqi=%d, Q_prime_ri=%d\n",Q_prime_ack, Q_prime_cqi, Q_prime_ri); return SRSLTE_SUCCESS; }