diff --git a/openair1/PHY/LTE_TRANSPORT/defs.h b/openair1/PHY/LTE_TRANSPORT/defs.h
index 83b34971da55abc83024b28a3a615e75d85916de..01d6cdc449a01feaa793df2039a6786580648956 100644
--- a/openair1/PHY/LTE_TRANSPORT/defs.h
+++ b/openair1/PHY/LTE_TRANSPORT/defs.h
@@ -360,6 +360,10 @@ typedef struct {
uint8_t TPC;
/// First Allocated RB
uint16_t first_rb;
+ /// First Allocated RB - previous scheduling
+ /// This is needed for PHICH generation which
+ /// is done after a new scheduling
+ uint16_t previous_first_rb;
/// Current Number of RBs
uint16_t nb_rb;
/// Transport block size
@@ -444,6 +448,10 @@ typedef struct {
uint8_t Nsymb_initial;
/// n_DMRS for cyclic shift of DMRS (36.213 Table 9.1.2-2)
uint8_t n_DMRS;
+ /// n_DMRS for cyclic shift of DMRS (36.213 Table 9.1.2-2) - previous scheduling
+ /// This is needed for PHICH generation which
+ /// is done after a new scheduling
+ uint8_t previous_n_DMRS;
/// n_DMRS 2 for cyclic shift of DMRS (36.211 Table 5.5.1.1.-1)
uint8_t n_DMRS2;
/// Flag to indicate that this ULSCH is for calibration information sent from UE (i.e. no MAC SDU to pass up)
diff --git a/openair1/PHY/LTE_TRANSPORT/phich.c b/openair1/PHY/LTE_TRANSPORT/phich.c
index 1727ec53242739fd603665c08e08e15d7e4443ec..b0665d89ce2659e6b8703b902e94287dff265365 100644
--- a/openair1/PHY/LTE_TRANSPORT/phich.c
+++ b/openair1/PHY/LTE_TRANSPORT/phich.c
@@ -1453,8 +1453,12 @@ void generate_phich_top(PHY_VARS_eNB *eNB,
LOG_D(PHY,"[eNB][PUSCH %d/%x] Frame %d subframe %d (pusch_subframe %d,pusch_frame %d) phich active %d\n",
harq_pid,ulsch[UE_id]->rnti,proc->frame_tx,subframe,pusch_subframe,pusch_frame,ulsch[UE_id]->harq_processes[harq_pid]->phich_active);
- ngroup_PHICH = (ulsch[UE_id]->harq_processes[harq_pid]->first_rb +
- ulsch[UE_id]->harq_processes[harq_pid]->n_DMRS)%Ngroup_PHICH;
+ /* the HARQ process may have been reused by a new scheduling, so we use
+ * previous values of first_rb and n_DMRS to compute ngroup_PHICH and nseq_PHICH
+ */
+
+ ngroup_PHICH = (ulsch[UE_id]->harq_processes[harq_pid]->previous_first_rb +
+ ulsch[UE_id]->harq_processes[harq_pid]->previous_n_DMRS)%Ngroup_PHICH;
if ((frame_parms->tdd_config == 0) && (frame_parms->frame_type == TDD) ) {
@@ -1462,20 +1466,20 @@ void generate_phich_top(PHY_VARS_eNB *eNB,
ngroup_PHICH += Ngroup_PHICH;
}
- nseq_PHICH = ((ulsch[UE_id]->harq_processes[harq_pid]->first_rb/Ngroup_PHICH) +
- ulsch[UE_id]->harq_processes[harq_pid]->n_DMRS)%(2*NSF_PHICH);
+ nseq_PHICH = ((ulsch[UE_id]->harq_processes[harq_pid]->previous_first_rb/Ngroup_PHICH) +
+ ulsch[UE_id]->harq_processes[harq_pid]->previous_n_DMRS)%(2*NSF_PHICH);
LOG_D(PHY,"[eNB %d][PUSCH %d] Frame %d subframe %d Generating PHICH, ngroup_PHICH %d/%d, nseq_PHICH %d : HI %d, first_rb %d dci_alloc %d)\n",
eNB->Mod_id,harq_pid,proc->frame_tx,
subframe,ngroup_PHICH,Ngroup_PHICH,nseq_PHICH,
ulsch[UE_id]->harq_processes[harq_pid]->phich_ACK,
- ulsch[UE_id]->harq_processes[harq_pid]->first_rb,
+ ulsch[UE_id]->harq_processes[harq_pid]->previous_first_rb,
ulsch[UE_id]->harq_processes[harq_pid]->dci_alloc);
if (ulsch[UE_id]->Msg3_active == 1) {
LOG_D(PHY,"[eNB %d][PUSCH %d][RAPROC] Frame %d, subframe %d: Generating Msg3 PHICH for UE %d, ngroup_PHICH %d/%d, nseq_PHICH %d : HI %d, first_rb %d\n",
eNB->Mod_id,harq_pid,proc->frame_tx,subframe,
UE_id,ngroup_PHICH,Ngroup_PHICH,nseq_PHICH,ulsch[UE_id]->harq_processes[harq_pid]->phich_ACK,
- ulsch[UE_id]->harq_processes[harq_pid]->first_rb);
+ ulsch[UE_id]->harq_processes[harq_pid]->previous_first_rb);
}
if (eNB->abstraction_flag == 0) {
diff --git a/openair1/SCHED/phy_procedures_lte_eNb.c b/openair1/SCHED/phy_procedures_lte_eNb.c
index 4163b8340c0aa2c1c5d2073af7955397922f8ce3..7ac6e2bf1fe6e7a148df8a1434d633a53807b093 100644
--- a/openair1/SCHED/phy_procedures_lte_eNb.c
+++ b/openair1/SCHED/phy_procedures_lte_eNb.c
@@ -1206,6 +1206,38 @@ void phy_procedures_eNB_TX(PHY_VARS_eNB *eNB,
eNB->dlsch[i][0]->subframe_tx[subframe] = 0;
}
+ /* save old HARQ information needed for PHICH generation */
+ for (i=0; i<NUMBER_OF_UE_MAX; i++) {
+ if (eNB->ulsch[i]) {
+ /* Store first_rb and n_DMRS for correct PHICH generation below.
+ * For PHICH generation we need "old" values of last scheduling
+ * for this HARQ process. 'generate_eNB_dlsch_params' below will
+ * overwrite first_rb and n_DMRS and 'generate_phich_top', done
+ * after 'generate_eNB_dlsch_params', would use the "new" values
+ * instead of the "old" ones.
+ *
+ * This has been tested for FDD only, may be wrong for TDD.
+ *
+ * TODO: maybe we should restructure the code to be sure it
+ * is done correctly. The main concern is if the code
+ * changes and first_rb and n_DMRS are modified before
+ * we reach here, then the PHICH processing will be wrong,
+ * using wrong first_rb and n_DMRS values to compute
+ * ngroup_PHICH and nseq_PHICH.
+ *
+ * TODO: check if that works with TDD.
+ */
+ if ((subframe_select(fp,ul_subframe)==SF_UL) ||
+ (fp->frame_type == FDD)) {
+ harq_pid = subframe2harq_pid(fp,ul_frame,ul_subframe);
+ eNB->ulsch[i]->harq_processes[harq_pid]->previous_first_rb =
+ eNB->ulsch[i]->harq_processes[harq_pid]->first_rb;
+ eNB->ulsch[i]->harq_processes[harq_pid]->previous_n_DMRS =
+ eNB->ulsch[i]->harq_processes[harq_pid]->n_DMRS;
+ }
+ }
+ }
+
num_pdcch_symbols = DCI_pdu->num_pdcch_symbols;
LOG_D(PHY,"num_pdcch_symbols %"PRIu8",(dci common %"PRIu8", dci uespec %"PRIu8"\n",num_pdcch_symbols,