From 77ac69796d2a92626d9b2c985ce9b83571d86b50 Mon Sep 17 00:00:00 2001 From: Francisco Date: Fri, 5 Mar 2021 17:08:57 +0000 Subject: [PATCH] sched,bug: change tbs/mcs derivation functions to forbid the use of alt cqi table for DCI format1A --- .../stack/mac/sched_ue_ctrl/sched_ue_cell.h | 13 ++- .../src/stack/mac/sched_phy_ch/sched_dci.cc | 4 +- srsenb/src/stack/mac/sched_ue.cc | 12 +-- .../stack/mac/sched_ue_ctrl/sched_ue_cell.cc | 80 +++++++++---------- 4 files changed, 54 insertions(+), 55 deletions(-) diff --git a/srsenb/hdr/stack/mac/sched_ue_ctrl/sched_ue_cell.h b/srsenb/hdr/stack/mac/sched_ue_ctrl/sched_ue_cell.h index 1aaacdf67..fce2c340c 100644 --- a/srsenb/hdr/stack/mac/sched_ue_ctrl/sched_ue_cell.h +++ b/srsenb/hdr/stack/mac/sched_ue_ctrl/sched_ue_cell.h @@ -89,11 +89,18 @@ private: * TBS/MCS derivation ************************************************************/ -tbs_info alloc_tbs_dl(const sched_ue_cell& cell, uint32_t nof_prb, uint32_t nof_re, int req_bytes = -1); +tbs_info cqi_to_tbs_dl(const sched_ue_cell& cell, + uint32_t nof_prb, + uint32_t nof_re, + srslte_dci_format_t dci_format, + int req_bytes = -1); tbs_info -alloc_tbs_ul(const sched_ue_cell& cell, uint32_t nof_prb, uint32_t nof_re, int req_bytes = -1, int explicit_mcs = -1); +cqi_to_tbs_ul(const sched_ue_cell& cell, uint32_t nof_prb, uint32_t nof_re, int req_bytes = -1, int explicit_mcs = -1); -int get_required_prb_dl(const sched_ue_cell& cell, tti_point tti_tx_dl, uint32_t req_bytes); +int get_required_prb_dl(const sched_ue_cell& cell, + tti_point tti_tx_dl, + srslte_dci_format_t dci_format, + uint32_t req_bytes); uint32_t get_required_prb_ul(const sched_ue_cell& cell, uint32_t req_bytes); } // namespace srsenb diff --git a/srsenb/src/stack/mac/sched_phy_ch/sched_dci.cc b/srsenb/src/stack/mac/sched_phy_ch/sched_dci.cc index e04482c3a..cdd5b7c9d 100644 --- a/srsenb/src/stack/mac/sched_phy_ch/sched_dci.cc +++ b/srsenb/src/stack/mac/sched_phy_ch/sched_dci.cc @@ -130,11 +130,9 @@ tbs_info compute_min_mcs_and_tbs_from_required_bytes(uint32_t nof_prb, bool ulqam64_enabled, bool use_tbs_index_alt) { - assert(req_bytes > 0); - // get max MCS/TBS that meets max coderate requirements tbs_info tb_max = compute_mcs_and_tbs(nof_prb, nof_re, cqi, max_mcs, is_ul, ulqam64_enabled, use_tbs_index_alt); - if (tb_max.tbs_bytes + 8 <= (int)req_bytes or tb_max.mcs == 0) { + if (tb_max.tbs_bytes + 8 <= (int)req_bytes or tb_max.mcs == 0 or req_bytes <= 0) { // if mcs cannot be lowered or a decrease in TBS index won't meet req_bytes requirement return tb_max; } diff --git a/srsenb/src/stack/mac/sched_ue.cc b/srsenb/src/stack/mac/sched_ue.cc index 6553a4bae..e517753aa 100644 --- a/srsenb/src/stack/mac/sched_ue.cc +++ b/srsenb/src/stack/mac/sched_ue.cc @@ -481,7 +481,7 @@ tbs_info sched_ue::compute_mcs_and_tbs(uint32_t enb_cc_idx, uint32_t nof_re = cells[enb_cc_idx].cell_cfg->get_dl_nof_res(tti_tx_dl, dci, cfi); // Compute MCS+TBS - tbs_info tb = alloc_tbs_dl(cells[enb_cc_idx], nof_alloc_prbs, nof_re, req_bytes.stop()); + tbs_info tb = cqi_to_tbs_dl(cells[enb_cc_idx], nof_alloc_prbs, nof_re, dci.format, req_bytes.stop()); if (tb.tbs_bytes > 0 and tb.tbs_bytes < (int)req_bytes.start()) { logger.info("SCHED: Could not get PRB allocation that avoids MAC CE or RLC SRB0 PDU segmentation"); @@ -613,7 +613,7 @@ int sched_ue::generate_format0(sched_interface::ul_sched_data_t* data, uint32_t N_srs = 0; uint32_t nof_symb = 2 * (SRSLTE_CP_NSYMB(cell.cp) - 1) - N_srs; uint32_t nof_re = nof_symb * alloc.length() * SRSLTE_NRE; - tbinfo = alloc_tbs_ul(cells[enb_cc_idx], alloc.length(), nof_re, req_bytes); + tbinfo = cqi_to_tbs_ul(cells[enb_cc_idx], alloc.length(), nof_re, req_bytes); // Reduce MCS to fit UCI if transmitted in this grant if (uci_type != UCI_PUSCH_NONE) { @@ -632,7 +632,7 @@ int sched_ue::generate_format0(sched_interface::ul_sched_data_t* data, } // Recompute again the MCS and TBS with the new spectral efficiency (based on the available RE for data) if (nof_re >= nof_uci_re) { - tbinfo = alloc_tbs_ul(cells[enb_cc_idx], alloc.length(), nof_re - nof_uci_re, req_bytes); + tbinfo = cqi_to_tbs_ul(cells[enb_cc_idx], alloc.length(), nof_re - nof_uci_re, req_bytes); } // NOTE: if (nof_re < nof_uci_re) we should set TBS=0 } @@ -738,7 +738,7 @@ rbg_interval sched_ue::get_required_dl_rbgs(uint32_t enb_cc_idx) if (req_bytes == srslte::interval{0, 0}) { return {0, 0}; } - int pending_prbs = get_required_prb_dl(cells[enb_cc_idx], to_tx_dl(current_tti), req_bytes.start()); + int pending_prbs = get_required_prb_dl(cells[enb_cc_idx], to_tx_dl(current_tti), get_dci_format(), req_bytes.start()); if (pending_prbs < 0) { // Cannot fit allocation in given PRBs logger.error("SCHED: DL CQI=%d does now allow fitting %d non-segmentable DL tx bytes into the cell bandwidth. " @@ -748,8 +748,8 @@ rbg_interval sched_ue::get_required_dl_rbgs(uint32_t enb_cc_idx) return {cellparams->nof_prb(), cellparams->nof_prb()}; } uint32_t min_pending_rbg = cellparams->nof_prbs_to_rbgs(pending_prbs); - pending_prbs = get_required_prb_dl(cells[enb_cc_idx], to_tx_dl(current_tti), req_bytes.stop()); - pending_prbs = (pending_prbs < 0) ? cellparams->nof_prb() : pending_prbs; + pending_prbs = get_required_prb_dl(cells[enb_cc_idx], to_tx_dl(current_tti), get_dci_format(), req_bytes.stop()); + pending_prbs = (pending_prbs < 0) ? cellparams->nof_prb() : pending_prbs; uint32_t max_pending_rbg = cellparams->nof_prbs_to_rbgs(pending_prbs); return {min_pending_rbg, max_pending_rbg}; } diff --git a/srsenb/src/stack/mac/sched_ue_ctrl/sched_ue_cell.cc b/srsenb/src/stack/mac/sched_ue_ctrl/sched_ue_cell.cc index e1d83f4cb..c4879434c 100644 --- a/srsenb/src/stack/mac/sched_ue_ctrl/sched_ue_cell.cc +++ b/srsenb/src/stack/mac/sched_ue_ctrl/sched_ue_cell.cc @@ -221,61 +221,52 @@ std::tuple false_position_method(int x1, int x2, YType y return false_position_method(x1, x2, y0, f, [](int x) { return false; }); } -/** - * In this scheduler we tend to use all the available bandwidth and select the MCS - * that approximates the minimum between the capacity and the requested rate - */ -tbs_info cqi_to_tbs(const sched_ue_cell& cell, uint32_t nof_prb, uint32_t nof_re, int req_bytes, bool is_ul) +tbs_info cqi_to_tbs_dl(const sched_ue_cell& cell, + uint32_t nof_prb, + uint32_t nof_re, + srslte_dci_format_t dci_format, + int req_bytes) { - // TODO: Compute real spectral efficiency based on PUSCH-UCI configuration - using ul64qam_cap = sched_interface::ue_cfg_t::ul64qam_cap; - uint32_t cqi = (is_ul) ? cell.ul_cqi : cell.dl_cqi; - uint32_t max_mcs = (is_ul) ? cell.max_mcs_ul : cell.max_mcs_dl; - bool ulqam64_enabled = is_ul and cell.get_ue_cfg()->support_ul64qam == ul64qam_cap::enabled; - bool use_tbs_index_alt = not is_ul and cell.get_ue_cfg()->use_tbs_index_alt; - - tbs_info tb; - if (req_bytes <= 0) { - tb = compute_mcs_and_tbs(nof_prb, nof_re, cqi, max_mcs, is_ul, ulqam64_enabled, use_tbs_index_alt); - } else { - tb = compute_min_mcs_and_tbs_from_required_bytes( - nof_prb, nof_re, cqi, max_mcs, req_bytes, is_ul, ulqam64_enabled, use_tbs_index_alt); - } - - // If coderate > SRSLTE_MIN(max_coderate, 0.930 * Qm) we should set TBS=0. We don't because it's not correctly - // handled by the scheduler, but we might be scheduling undecodable codewords at very low SNR - if (tb.tbs_bytes < 0) { - tb.mcs = 0; - tb.tbs_bytes = get_tbs_bytes((uint32_t)tb.mcs, nof_prb, use_tbs_index_alt, is_ul); - } - - return tb; -} + bool use_tbs_index_alt = cell.get_ue_cfg()->use_tbs_index_alt and dci_format != SRSLTE_DCI_FORMAT1A; -tbs_info alloc_tbs_dl(const sched_ue_cell& cell, uint32_t nof_prb, uint32_t nof_re, int req_bytes) -{ tbs_info ret; - - // Use a higher MCS for the Msg4 to fit in the 6 PRB case if (cell.fixed_mcs_dl < 0 or not cell.dl_cqi_rx) { // Dynamic MCS - ret = cqi_to_tbs(cell, nof_prb, nof_re, req_bytes, false); + ret = compute_min_mcs_and_tbs_from_required_bytes( + nof_prb, nof_re, cell.dl_cqi, cell.max_mcs_dl, req_bytes, false, false, use_tbs_index_alt); + + // If coderate > SRSLTE_MIN(max_coderate, 0.930 * Qm) we should set TBS=0. We don't because it's not correctly + // handled by the scheduler, but we might be scheduling undecodable codewords at very low SNR + if (ret.tbs_bytes < 0) { + ret.mcs = 0; + ret.tbs_bytes = get_tbs_bytes((uint32_t)ret.mcs, nof_prb, use_tbs_index_alt, false); + } } else { // Fixed MCS ret.mcs = cell.fixed_mcs_dl; - ret.tbs_bytes = get_tbs_bytes((uint32_t)cell.fixed_mcs_dl, nof_prb, cell.get_ue_cfg()->use_tbs_index_alt, false); + ret.tbs_bytes = get_tbs_bytes((uint32_t)cell.fixed_mcs_dl, nof_prb, use_tbs_index_alt, false); } return ret; } -tbs_info alloc_tbs_ul(const sched_ue_cell& cell, uint32_t nof_prb, uint32_t nof_re, int req_bytes, int explicit_mcs) +tbs_info cqi_to_tbs_ul(const sched_ue_cell& cell, uint32_t nof_prb, uint32_t nof_re, int req_bytes, int explicit_mcs) { - tbs_info ret; - int mcs = explicit_mcs >= 0 ? explicit_mcs : cell.fixed_mcs_ul; + using ul64qam_cap = sched_interface::ue_cfg_t::ul64qam_cap; + int mcs = explicit_mcs >= 0 ? explicit_mcs : cell.fixed_mcs_ul; + bool ulqam64_enabled = cell.get_ue_cfg()->support_ul64qam == ul64qam_cap::enabled; + tbs_info ret; if (mcs < 0) { // Dynamic MCS - ret = cqi_to_tbs(cell, nof_prb, nof_re, req_bytes, true); + ret = compute_min_mcs_and_tbs_from_required_bytes( + nof_prb, nof_re, cell.ul_cqi, cell.max_mcs_ul, req_bytes, true, ulqam64_enabled, false); + + // If coderate > SRSLTE_MIN(max_coderate, 0.930 * Qm) we should set TBS=0. We don't because it's not correctly + // handled by the scheduler, but we might be scheduling undecodable codewords at very low SNR + if (ret.tbs_bytes < 0) { + ret.mcs = 0; + ret.tbs_bytes = get_tbs_bytes((uint32_t)ret.mcs, nof_prb, false, true); + } } else { // Fixed MCS ret.mcs = mcs; @@ -285,11 +276,14 @@ tbs_info alloc_tbs_ul(const sched_ue_cell& cell, uint32_t nof_prb, uint32_t nof_ return ret; } -int get_required_prb_dl(const sched_ue_cell& cell, tti_point tti_tx_dl, uint32_t req_bytes) +int get_required_prb_dl(const sched_ue_cell& cell, + tti_point tti_tx_dl, + srslte_dci_format_t dci_format, + uint32_t req_bytes) { - auto compute_tbs_approx = [tti_tx_dl, &cell](uint32_t nof_prb) { + auto compute_tbs_approx = [tti_tx_dl, &cell, dci_format](uint32_t nof_prb) { uint32_t nof_re = cell.cell_cfg->get_dl_lb_nof_re(tti_tx_dl, nof_prb); - tbs_info tb = alloc_tbs_dl(cell, nof_prb, nof_re, -1); + tbs_info tb = cqi_to_tbs_dl(cell, nof_prb, nof_re, dci_format, -1); return tb.tbs_bytes; }; @@ -308,7 +302,7 @@ uint32_t get_required_prb_ul(const sched_ue_cell& cell, uint32_t req_bytes) auto compute_tbs_approx = [&cell](uint32_t nof_prb) { const uint32_t N_srs = 0; uint32_t nof_re = (2 * (SRSLTE_CP_NSYMB(cell.cell_cfg->cfg.cell.cp) - 1) - N_srs) * nof_prb * SRSLTE_NRE; - return alloc_tbs_ul(cell, nof_prb, nof_re, -1).tbs_bytes; + return cqi_to_tbs_ul(cell, nof_prb, nof_re, -1).tbs_bytes; }; // find nof prbs that lead to a tbs just above req_bytes