From 0773229b1a0c9ad61398692c3d1cc3624e648491 Mon Sep 17 00:00:00 2001
From: Robert Schmidt <robert.schmidt@eurecom.fr>
Date: Wed, 23 Dec 2020 14:48:24 +0100
Subject: [PATCH] Implement UL HARQ using NR_list_t
---
doc/SW_archi.md | 2 +-
.../LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c | 2 +
.../LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c | 126 +++++++++---------
openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h | 9 +-
4 files changed, 72 insertions(+), 67 deletions(-)
diff --git a/doc/SW_archi.md b/doc/SW_archi.md
index 412dad402d9..d92f8021488 100644
--- a/doc/SW_archi.md
+++ b/doc/SW_archi.md
@@ -186,7 +186,7 @@ development], for FR2 does not exist yet.
3) allocate a CCE for the UE (and return if it is not possible)
4) Calculate DMRS stuff (nr_save_pusch_fields()) and the TBS.
5) Mark used resources in vrb_map_UL.
-* loop through all users: get a free HARQ PID using select_ul_harq_pid() and
+* loop through all users: get a free HARQ PID and
update statistics. Fill nFAPI structures directly for PUSCH, and call
config_uldci() and fill_dci_pdu_rel15() for DCI filling and PDCCH messages.
diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c
index d509aa33abb..e3532d94738 100644
--- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c
+++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c
@@ -477,6 +477,8 @@ void nr_ul_preprocessor_phytest(module_id_t module_id,
sched_pusch->mcs = mcs;
sched_pusch->rbStart = rbStart;
sched_pusch->rbSize = rbSize;
+ /* get the PID of a HARQ process awaiting retransmission, or -1 for "any new" */
+ sched_pusch->ul_harq_pid = sched_ctrl->retrans_ul_harq.head;
/* Calculate TBS from MCS */
sched_pusch->R = nr_get_code_rate_ul(mcs, ps->mcs_table);
diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c
index e2ecb9c38e0..be2a478b40e 100644
--- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c
+++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c
@@ -259,45 +259,47 @@ void handle_nr_ul_harq(module_id_t mod_id,
NR_UE_info_t *UE_info = &RC.nrmac[mod_id]->UE_info;
NR_UE_sched_ctrl_t *sched_ctrl = &UE_info->UE_sched_ctrl[UE_id];
- int max_harq_rounds = 4; // TODO define macro
- uint8_t hrq_id = crc_pdu->harq_id;
- NR_UE_ul_harq_t *cur_harq = &sched_ctrl->ul_harq_processes[hrq_id];
- if (cur_harq->state==ACTIVE_SCHED) {
- if (!crc_pdu->tb_crc_status) {
- cur_harq->ndi ^= 1;
- cur_harq->round = 0;
- cur_harq->state = INACTIVE; // passed -> make inactive. can be used by scheduder for next grant
- LOG_D(MAC,
- "Ulharq id %d crc passed for RNTI %04x\n",
- hrq_id,
- crc_pdu->rnti);
- } else {
- cur_harq->round++;
- cur_harq->state = ACTIVE_NOT_SCHED;
- LOG_D(MAC,
- "Ulharq id %d crc failed for RNTI %04x\n",
- hrq_id,
- crc_pdu->rnti);
- }
-
- if (!(cur_harq->round<max_harq_rounds)) {
- cur_harq->ndi ^= 1;
- cur_harq->state = INACTIVE; // failed after 4 rounds -> make inactive
- cur_harq->round = 0;
- LOG_D(MAC,
- "RNTI %04x: Ulharq id %d crc failed in all rounds\n",
- crc_pdu->rnti,
- hrq_id);
- UE_info->mac_stats[UE_id].ulsch_errors++;
- }
- return;
- } else
+ const int8_t harq_pid = sched_ctrl->feedback_ul_harq.head;
+ if (crc_pdu->harq_id != harq_pid && harq_pid < 0) {
LOG_W(MAC,
- "Incorrect ULSCH HARQ PID %d or invalid state %d for RNTI %04x "
- "(ignore this warning for RA)\n",
- hrq_id,
- cur_harq->state,
+ "Unexpected ULSCH HARQ PID %d (have %d) for RNTI %04x (ignore this warning for RA)\n",
+ crc_pdu->harq_id,
+ harq_pid,
+ crc_pdu->rnti);
+ return;
+ }
+ DevAssert(harq_pid == crc_pdu->harq_id);
+ remove_front_nr_list(&sched_ctrl->feedback_ul_harq);
+ NR_UE_ul_harq_t *harq = &sched_ctrl->ul_harq_processes[harq_pid];
+ DevAssert(harq->feedback_slot == slot - 1);
+ DevAssert(harq->is_waiting);
+ harq->feedback_slot = -1;
+ harq->is_waiting = false;
+ if (!crc_pdu->tb_crc_status) {
+ harq->ndi ^= 1;
+ harq->round = 0;
+ LOG_D(MAC,
+ "Ulharq id %d crc passed for RNTI %04x\n",
+ harq_pid,
crc_pdu->rnti);
+ add_tail_nr_list(&sched_ctrl->available_ul_harq, harq_pid);
+ } else if (harq->round == MAX_HARQ_ROUNDS) {
+ harq->ndi ^= 1;
+ harq->round = 0;
+ LOG_D(MAC,
+ "RNTI %04x: Ulharq id %d crc failed in all rounds\n",
+ crc_pdu->rnti,
+ harq_pid);
+ UE_info->mac_stats[UE_id].ulsch_errors++;
+ add_tail_nr_list(&sched_ctrl->available_ul_harq, harq_pid);
+ } else {
+ harq->round++;
+ LOG_D(MAC,
+ "Ulharq id %d crc failed for RNTI %04x\n",
+ harq_pid,
+ crc_pdu->rnti);
+ add_tail_nr_list(&sched_ctrl->retrans_ul_harq, harq_pid);
+ }
}
/*
@@ -432,29 +434,6 @@ long get_K2(NR_BWP_Uplink_t *ubwp, int time_domain_assignment, int mu) {
return 3;
}
-int8_t select_ul_harq_pid(NR_UE_sched_ctrl_t *sched_ctrl) {
- const uint8_t max_ul_harq_pids = 3; // temp: for testing
- // schedule active harq processes
- for (uint8_t hrq_id = 0; hrq_id < max_ul_harq_pids; hrq_id++) {
- NR_UE_ul_harq_t *cur_harq = &sched_ctrl->ul_harq_processes[hrq_id];
- if (cur_harq->state == ACTIVE_NOT_SCHED) {
- LOG_D(MAC, "Found ulharq id %d, scheduling it for retransmission\n", hrq_id);
- return hrq_id;
- }
- }
-
- // schedule new harq processes
- for (uint8_t hrq_id=0; hrq_id < max_ul_harq_pids; hrq_id++) {
- NR_UE_ul_harq_t *cur_harq = &sched_ctrl->ul_harq_processes[hrq_id];
- if (cur_harq->state == INACTIVE) {
- LOG_D(MAC, "Found new ulharq id %d, scheduling it\n", hrq_id);
- return hrq_id;
- }
- }
- LOG_E(MAC, "All UL HARQ processes are busy. Cannot schedule ULSCH\n");
- return -1;
-}
-
void nr_simple_ulsch_preprocessor(module_id_t module_id,
frame_t frame,
sub_frame_t slot,
@@ -502,6 +481,8 @@ void nr_simple_ulsch_preprocessor(module_id_t module_id,
sched_ctrl->sched_pusch.slot = sched_slot;
sched_ctrl->sched_pusch.frame = sched_frame;
+ /* get the PID of a HARQ process awaiting retransmission, or -1 otherwise */
+ sched_ctrl->sched_pusch.ul_harq_pid = sched_ctrl->retrans_ul_harq.head;
const int target_ss = NR_SearchSpace__searchSpaceType_PR_ue_Specific;
sched_ctrl->search_space = get_searchspace(sched_ctrl->active_bwp, target_ss);
@@ -605,11 +586,28 @@ void nr_schedule_ulsch(module_id_t module_id,
uint16_t rnti = UE_info->rnti[UE_id];
- int8_t harq_id = select_ul_harq_pid(sched_ctrl);
- if (harq_id < 0) return;
+ int8_t harq_id = sched_pusch->ul_harq_pid;
+ if (harq_id < 0) {
+ /* PP has not selected a specific HARQ Process, get a new one */
+ harq_id = sched_ctrl->available_ul_harq.head;
+ AssertFatal(harq_id >= 0,
+ "no free HARQ process available for UE %d\n",
+ UE_id);
+ remove_front_nr_list(&sched_ctrl->available_ul_harq);
+ } else {
+ /* PP selected a specific HARQ process. Check whether it will be a new
+ * transmission or a retransmission, and remove from the corresponding
+ * list */
+ if (sched_ctrl->ul_harq_processes[harq_id].round == 0)
+ remove_nr_list(&sched_ctrl->available_ul_harq, harq_id);
+ else
+ remove_nr_list(&sched_ctrl->retrans_ul_harq, harq_id);
+ }
NR_UE_ul_harq_t *cur_harq = &sched_ctrl->ul_harq_processes[harq_id];
- cur_harq->state = ACTIVE_SCHED;
- cur_harq->last_tx_slot = sched_pusch->slot;
+ DevAssert(!cur_harq->is_waiting);
+ add_tail_nr_list(&sched_ctrl->feedback_ul_harq, harq_id);
+ cur_harq->feedback_slot = sched_pusch->slot;
+ cur_harq->is_waiting = true;
int rnti_types[2] = { NR_RNTI_C, 0 };
diff --git a/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h b/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
index 3e35cd7385a..10811d575b2 100644
--- a/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
+++ b/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
@@ -336,6 +336,9 @@ typedef struct NR_sched_pusch {
uint16_t R;
uint8_t Qm;
uint32_t tb_size;
+
+ /// UL HARQ PID to use for this UE, or -1 for "any new"
+ int8_t ul_harq_pid;
} NR_sched_pusch_t;
typedef struct NR_UE_harq {
@@ -360,10 +363,12 @@ typedef enum {
} NR_UL_harq_states_t;
typedef struct NR_UE_ul_harq {
+ bool is_waiting;
uint8_t ndi;
uint8_t round;
- uint16_t last_tx_slot;
- NR_UL_harq_states_t state;
+ uint16_t feedback_slot;
+
+ /* TODO PUSCH of last transmission */
} NR_UE_ul_harq_t;
--
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