From 16f028dba56b88148ffaf0e84e35d097a2b4eedf Mon Sep 17 00:00:00 2001 From: Bartosz Podrygajlo Date: Mon, 21 Oct 2024 10:54:55 +0200 Subject: [PATCH] Dynamic PDCCH aggregation level The aggregation level search order for PDCCH candidates is modified: - the search starts from desired_agg_level_index, which is a value from 0 to 4 proportial to pdcch_cl_adjust. - pdcch_cl_adjust is a value between 0 and 1 that indicates PDCCH channel quality by averaging HARQ DTX rate. A value of 0 means perfect channel, a value o 1 means impaired channel. --- doc/MAC/mac-usage.md | 22 +++++++++ openair1/PHY/NR_TRANSPORT/nr_dci.c | 5 +- openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c | 8 ++-- .../LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c | 6 ++- .../LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c | 6 ++- .../NR_MAC_gNB/gNB_scheduler_primitives.c | 47 ++++++++++++++++--- .../LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c | 1 + .../LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c | 9 ++-- openair2/LAYER2/NR_MAC_gNB/mac_proto.h | 4 +- openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h | 13 +++++ 10 files changed, 102 insertions(+), 19 deletions(-) diff --git a/doc/MAC/mac-usage.md b/doc/MAC/mac-usage.md index f96f94d522..8141e50df3 100644 --- a/doc/MAC/mac-usage.md +++ b/doc/MAC/mac-usage.md @@ -38,6 +38,28 @@ The actual scheduler implementation can be found in functions `pf_dl()` and [`gNB_scheduler_ulsch.c`](../../openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c) (for UL), respectively. +## PDDCH aggregation level + +PDCCH aggregation level is selected using closed loop controller, where DL HARQ +feedback is the controller feedback signal. It is used to increment `pdcch_cl_adjust` +variable if no feedback is detected and decrement the variable when feedback is detected. +`pdcch_cl_adjust` is later mapped PDCCH aggregation level range. + +The value of `pdcch_cl_adjust` is clamped to range <0,1>, the increment value is 0.05 while +the decrement value is 0.01. + +### Examples: +#### Example 1: +Say we have 90% PDCCH success rate at aggregation level 1, `pdcch_cl_adjust` will stay at 0 +for most of the time. 2 consecutive PDCCH failures will not result in increasing the aggregation +level (because (0.05 + 0.05) * 4 = 0.4 which is closer to 0 than to 1). If PDCCH fails 3 times +in a row the aggregation level will change to 2 and hopefully back to 1 once more PDDCH successes +happen. + +### Example 2 +Say we have 0% PDCCH success rate (radio link failure scenario) but `pdcch_cl_adjust` is 0 indicating +perfect PDCCH channel. it would take ~18 PDCCH failures to reach maximum aggregation level. + # Periodic output and interpretation The scheduler periodically outputs statistics that can help you judge the radio diff --git a/openair1/PHY/NR_TRANSPORT/nr_dci.c b/openair1/PHY/NR_TRANSPORT/nr_dci.c index 9bda1b96c4..49f07063d2 100644 --- a/openair1/PHY/NR_TRANSPORT/nr_dci.c +++ b/openair1/PHY/NR_TRANSPORT/nr_dci.c @@ -99,7 +99,7 @@ static void nr_generate_dci(PHY_VARS_gNB *gNB, if (dci_pdu->RNTI != 0xFFFF) LOG_D(NR_PHY_DCI, "DL_DCI : rb_offset %d, nb_rb %d, DMRS length per symbol %d\t DCI encoded length %d (precoder_granularity %d, " - "reg_mapping %d), Scrambling_Id %d, ScramblingRNTI %x, PayloadSizeBits %d\n", + "reg_mapping %d), Scrambling_Id %d, ScramblingRNTI %x, PayloadSizeBits %d AggregationLevel %d\n", rb_offset, n_rb, dmrs_length, @@ -108,7 +108,8 @@ static void nr_generate_dci(PHY_VARS_gNB *gNB, pdcch_pdu_rel15->CceRegMappingType, dci_pdu->ScramblingId, dci_pdu->ScramblingRNTI, - dci_pdu->PayloadSizeBits); + dci_pdu->PayloadSizeBits, + dci_pdu->AggregationLevel); dmrs_length += rb_offset*6; // To accommodate more DMRS symbols in case of rb offset /// DMRS QPSK modulation diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c index 3f3cbbad12..2d61a7332e 100644 --- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c +++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c @@ -874,7 +874,8 @@ static void nr_generate_Msg3_retransmission(module_id_t module_idP, ss, coreset, &ra->sched_pdcch, - true); + true, + 0); if (CCEIndex < 0) { LOG_E(NR_MAC, "UE %04x cannot find free CCE!\n", ra->rnti); return; @@ -1484,7 +1485,7 @@ static void nr_generate_Msg2(module_id_t module_idP, } uint8_t aggregation_level; - int CCEIndex = get_cce_index(nr_mac, CC_id, slotP, 0, &aggregation_level, beam.idx, ss, coreset, &ra->sched_pdcch, true); + int CCEIndex = get_cce_index(nr_mac, CC_id, slotP, 0, &aggregation_level, beam.idx, ss, coreset, &ra->sched_pdcch, true, 0); if (CCEIndex < 0) { LOG_W(NR_MAC, "UE %04x: %d.%d cannot find free CCE for Msg2!\n", ra->rnti, frameP, slotP); @@ -2006,7 +2007,8 @@ static void nr_generate_Msg4_MsgB(module_id_t module_idP, ss, coreset, &ra->sched_pdcch, - true); + true, + 0); if (CCEIndex < 0) { LOG_E(NR_MAC, "Cannot find free CCE for RA RNTI 0x%04x!\n", ra->rnti); diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c index 8b6639a3e7..5660f2b6b5 100644 --- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c +++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c @@ -553,7 +553,8 @@ static bool allocate_dl_retransmission(module_id_t module_id, sched_ctrl->search_space, sched_ctrl->coreset, &sched_ctrl->sched_pdcch, - false); + false, + sched_ctrl->pdcch_cl_adjust); if (CCEIndex<0) { LOG_D(NR_MAC, "[UE %04x][%4d.%2d] could not find free CCE for DL DCI retransmission\n", UE->rnti, frame, slot); return false; @@ -817,7 +818,8 @@ static void pf_dl(module_id_t module_id, sched_ctrl->search_space, sched_ctrl->coreset, &sched_ctrl->sched_pdcch, - false); + false, + sched_ctrl->pdcch_cl_adjust); if (CCEIndex < 0) { LOG_D(NR_MAC, "[UE %04x][%4d.%2d] could not find free CCE for DL DCI\n", rnti, frame, slot); reset_beam_status(&mac->beam_info, diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c index 989aa1be9a..4aee39b45e 100644 --- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c +++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c @@ -148,7 +148,8 @@ void nr_preprocessor_phytest(module_id_t module_id, frame_t frame, sub_frame_t s sched_ctrl->search_space, sched_ctrl->coreset, &sched_ctrl->sched_pdcch, - false); + false, + 0); AssertFatal(CCEIndex >= 0, "Could not find CCE for UE %04x\n", UE->rnti); NR_sched_pdsch_t *sched_pdsch = &sched_ctrl->sched_pdsch; @@ -312,7 +313,8 @@ bool nr_ul_preprocessor_phytest(module_id_t module_id, frame_t frame, sub_frame_ sched_ctrl->search_space, sched_ctrl->coreset, &sched_ctrl->sched_pdcch, - false); + false, + 0); if (CCEIndex < 0) { LOG_E(MAC, "%s(): CCE list not empty, couldn't schedule PUSCH\n", __func__); return false; diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c index d6f63d46d1..2db589d0ee 100644 --- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c +++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c @@ -119,6 +119,9 @@ static const uint16_t cqi_table3[16][2] = {{0, 0}, {6, 6660}, {6, 7720}}; +static void determine_aggregation_level_search_order(int agg_level_search_order[NUM_PDCCH_AGG_LEVELS], + float pdcch_cl_adjust); + uint8_t get_dl_nrOfLayers(const NR_UE_sched_ctrl_t *sched_ctrl, const nr_dci_format_t dci_format) { @@ -550,15 +553,18 @@ int get_cce_index(const gNB_MAC_INST *nrmac, const NR_SearchSpace_t *ss, const NR_ControlResourceSet_t *coreset, NR_sched_pdcch_t *sched_pdcch, - bool is_common) + bool is_common, + float pdcch_cl_adjust) { - const uint32_t Y = is_common ? 0 : get_Y(ss, slot, rnti); uint8_t nr_of_candidates; - for (int i = 0; i < 5; i++) { - // for now taking the lowest value among the available aggregation levels - find_aggregation_candidates(aggregation_level, &nr_of_candidates, ss, 1 << i); - if(nr_of_candidates > 0) + + int agg_level_search_order[NUM_PDCCH_AGG_LEVELS]; + determine_aggregation_level_search_order(agg_level_search_order, pdcch_cl_adjust); + + for (int i = 0; i < NUM_PDCCH_AGG_LEVELS; i++) { + find_aggregation_candidates(aggregation_level, &nr_of_candidates, ss, 1 << agg_level_search_order[i]); + if (nr_of_candidates > 0) break; } int CCEIndex = find_pdcch_candidate(nrmac, CC_id, *aggregation_level, nr_of_candidates, beam_idx, sched_pdcch, coreset, Y); @@ -2516,6 +2522,7 @@ NR_UE_info_t *add_new_nr_ue(gNB_MAC_INST *nr_mac, rnti_t rntiP, NR_CellGroupConf sched_ctrl->ta_update = 31; sched_ctrl->sched_srs.frame = -1; sched_ctrl->sched_srs.slot = -1; + sched_ctrl->pdcch_cl_adjust = 0; // initialize LCID structure seq_arr_init(&sched_ctrl->lc_config, sizeof(nr_lc_config_t)); @@ -3524,3 +3531,31 @@ bool nr_mac_get_new_rnti(NR_UEs_t *UEs, const NR_RA_t *ra_base, int ra_count, rn } while (loop < 100 && (exist_connected_ue || exist_in_pending_ra_ue)); return loop < 100; // nothing found: loop count 100 } + +/// @brief Orders PDCCH aggregation levels so that we first check desired aggregation level according to +/// pdcch_cl_adjust +/// @param agg_level_search_order in/out 5-element array of aggregation levels from 0 to 4 +/// @param pdcch_cl_adjust value from 0 to 1 indication channel impariments (0 - good channel, 1 - bad channel) +static void determine_aggregation_level_search_order(int agg_level_search_order[NUM_PDCCH_AGG_LEVELS], float pdcch_cl_adjust) +{ + int desired_agg_level_index = round(4 * pdcch_cl_adjust); + int agg_level_search_index = 0; + for (int i = desired_agg_level_index; i < NUM_PDCCH_AGG_LEVELS; i++) { + agg_level_search_order[agg_level_search_index++] = i; + } + for (int i = desired_agg_level_index - 1; i >= 0; i--) { + agg_level_search_order[agg_level_search_index++] = i; + } +} + +/// @brief Update PDCCH closed loop adjust for UE depending on detection of feedback. +/// @param sched_ctrl UE scheduling control info +/// @param feedback_not_detected Whether feedback (PUSCH or HARQ) was detected +void nr_mac_update_pdcch_closed_loop_adjust(NR_UE_sched_ctrl_t *sched_ctrl, bool feedback_not_detected) +{ + if (feedback_not_detected) { + sched_ctrl->pdcch_cl_adjust = min(1, sched_ctrl->pdcch_cl_adjust + 0.05); + } else { + sched_ctrl->pdcch_cl_adjust = max(0, sched_ctrl->pdcch_cl_adjust - 0.01); + } +} diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c index 853a4a5ff8..cdf4861cff 100644 --- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c +++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c @@ -787,6 +787,7 @@ void handle_nr_uci_pucch_0_1(module_id_t mod_id, const int8_t pid = sched_ctrl->feedback_dl_harq.head; remove_front_nr_list(&sched_ctrl->feedback_dl_harq); LOG_D(NR_MAC,"%4d.%2d bit %d pid %d ack/nack %d\n",frame, slot, harq_bit,pid,harq_value); + nr_mac_update_pdcch_closed_loop_adjust(sched_ctrl, harq_confidence != 0); handle_dl_harq(UE, pid, harq_value == 0 && harq_confidence == 0, nrmac->dl_bler.harq_round_max); if (!UE->Msg4_MsgB_ACKed && harq_value == 0 && harq_confidence == 0) UE->Msg4_MsgB_ACKed = true; diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c index 3aacade706..a8efe1a98d 100644 --- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c +++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c @@ -1742,7 +1742,8 @@ static bool allocate_ul_retransmission(gNB_MAC_INST *nrmac, sched_ctrl->search_space, sched_ctrl->coreset, &sched_ctrl->sched_pdcch, - false); + false, + sched_ctrl->pdcch_cl_adjust); if (CCEIndex<0) { LOG_D(NR_MAC, "[UE %04x][%4d.%2d] no free CCE for retransmission UL DCI UE\n", UE->rnti, frame, slot); return false; @@ -1926,7 +1927,8 @@ static void pf_ul(module_id_t module_id, sched_ctrl->search_space, sched_ctrl->coreset, &sched_ctrl->sched_pdcch, - false); + false, + sched_ctrl->pdcch_cl_adjust); if (CCEIndex < 0) { LOG_D(NR_MAC, "[UE %04x][%4d.%2d] no free CCE for UL DCI (BSR 0)\n", UE->rnti, frame, slot); reset_beam_status(&nrmac->beam_info, sched_frame, sched_slot, UE->UE_beam_index, n, beam.new_beam); @@ -2073,7 +2075,8 @@ static void pf_ul(module_id_t module_id, sched_ctrl->search_space, sched_ctrl->coreset, &sched_ctrl->sched_pdcch, - false); + false, + sched_ctrl->pdcch_cl_adjust); if (CCEIndex < 0) { reset_beam_status(&nrmac->beam_info, frame, slot, iterator->UE->UE_beam_index, n_dl, dci_beam.new_beam); diff --git a/openair2/LAYER2/NR_MAC_gNB/mac_proto.h b/openair2/LAYER2/NR_MAC_gNB/mac_proto.h index ee66bcaf90..57f8a9dba5 100644 --- a/openair2/LAYER2/NR_MAC_gNB/mac_proto.h +++ b/openair2/LAYER2/NR_MAC_gNB/mac_proto.h @@ -433,7 +433,8 @@ int get_cce_index(const gNB_MAC_INST *nrmac, const NR_SearchSpace_t *ss, const NR_ControlResourceSet_t *coreset, NR_sched_pdcch_t *sched_pdcch, - bool is_common); + bool is_common, + float pdcch_cl_adjust); bool nr_find_nb_rb(uint16_t Qm, uint16_t R, @@ -493,5 +494,6 @@ bool nr_mac_add_lcid(NR_UE_sched_ctrl_t *sched_ctrl, const nr_lc_config_t *c); bool nr_mac_remove_lcid(NR_UE_sched_ctrl_t *sched_ctrl, long lcid); bool nr_mac_get_new_rnti(NR_UEs_t *UEs, const NR_RA_t *ra_base, int ra_count, rnti_t *rnti); +void nr_mac_update_pdcch_closed_loop_adjust(NR_UE_sched_ctrl_t *sched_ctrl, bool feedback_not_detected); #endif /*__LAYER2_NR_MAC_PROTO_H__*/ diff --git a/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h b/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h index c8604c431f..5abaa6f4c9 100644 --- a/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h +++ b/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h @@ -125,6 +125,15 @@ typedef enum { nrRA_WAIT_Msg4_MsgB_ACK, } RA_gNB_state_t; +typedef enum { + PDCCH_AGG_LEVEL1 = 0, + PDCCH_AGG_LEVEL2, + PDCCH_AGG_LEVEL4, + PDCCH_AGG_LEVEL8, + PDCCH_AGG_LEVEL16, + NUM_PDCCH_AGG_LEVELS +} Pdcch_Aggregation_Level_t; + static const char *const nrra_text[] = {"IDLE", "Msg2", "WAIT_MsgA_PUSCH", "WAIT_Msg3", "Msg3_retransmission", "Msg3_dcch_dtch", "Msg4", "MsgB", "WAIT_Msg4_ACK"}; @@ -675,6 +684,10 @@ typedef struct { /// per-LC configuration seq_arr_t lc_config; + + // pdcch closed loop adjust for PDCCH aggregation level, range <0, 1> + // 0 - good channel, 1 - bad channel + float pdcch_cl_adjust; } NR_UE_sched_ctrl_t; typedef struct {