fill dmrs mask depending on actual number of frontloaded symbols, not maxlength

openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.c

@@ -2352,10 +2352,6 @@ int get_num_dmrs(uint16_t dmrs_mask ) {
   for (int i=0;i<16;i++) num_dmrs+=((dmrs_mask>>i)&1);
   return(num_dmrs);
 }
-/* returns the total DMRS symbols in a slot*/
-uint8_t get_num_dmrs_symbols(NR_PDSCH_Config_t *pdsch_Config,int dmrs_TypeA_Position,int NrOfSymbols, int startSymbol, int mappingtype){
-  return get_num_dmrs(fill_dmrs_mask(pdsch_Config,dmrs_TypeA_Position,NrOfSymbols, startSymbol, mappingtype));
-}
 
 // Table 5.1.2.2.1-1 38.214
 uint8_t getRBGSize(uint16_t bwp_size, long rbg_size_config) {
@@ -3010,9 +3006,9 @@ int is_nr_UL_slot(NR_TDD_UL_DL_ConfigCommon_t	*tdd_UL_DL_ConfigurationCommon, sl
   else return(slot_in_period >= slots1+tdd_UL_DL_ConfigurationCommon->pattern2->nrofDownlinkSlots ? 1 : 0);    
 }
 
-int16_t fill_dmrs_mask(NR_PDSCH_Config_t *pdsch_Config,int dmrs_TypeA_Position,int NrOfSymbols, int startSymbol, int mappingtype_fromDCI) {
+int16_t fill_dmrs_mask(NR_PDSCH_Config_t *pdsch_Config,int dmrs_TypeA_Position,int NrOfSymbols, int startSymbol, int mappingtype_fromDCI, int length) {
 
-  int l0;int dmrs_AdditionalPosition = 0;int maxLength = 0;
+  int l0;int dmrs_AdditionalPosition = 0;
   NR_DMRS_DownlinkConfig_t *dmrs_config = NULL;
 
   LOG_D(MAC, "NrofSymbols:%d, startSymbol:%d, mappingtype:%d, dmrs_TypeA_Position:%d\n", NrOfSymbols, startSymbol, mappingtype_fromDCI, dmrs_TypeA_Position);
@@ -3024,7 +3020,6 @@ int16_t fill_dmrs_mask(NR_PDSCH_Config_t *pdsch_Config,int dmrs_TypeA_Position,i
   // in case of DCI FORMAT 1_0 or dedicated pdsch config not received additionposition = pos2, len1 should be used
   // referred to section 5.1.6.2 in 38.214
   dmrs_AdditionalPosition = 2;
-  maxLength = 1;
 
   if (pdsch_Config != NULL) {
     if (mappingtype_fromDCI == typeA) { // Type A
@@ -3039,8 +3034,7 @@ int16_t fill_dmrs_mask(NR_PDSCH_Config_t *pdsch_Config,int dmrs_TypeA_Position,i
 
     AssertFatal(dmrs_config != NULL," DMRS configs not present in PDSCH DMRS Downlink config\n");
 
-    // default values of maxlength = len2, additionalposition is pos2
-    if (dmrs_config->maxLength != NULL) maxLength = 2;
+    // default values of additionalposition is pos2
     if (dmrs_config->dmrs_AdditionalPosition != NULL) dmrs_AdditionalPosition = *dmrs_config->dmrs_AdditionalPosition;
   }
 
@@ -3055,11 +3049,6 @@ int16_t fill_dmrs_mask(NR_PDSCH_Config_t *pdsch_Config,int dmrs_TypeA_Position,i
   // For TypeB, ld is the duration of the scheduled PDSCH resources
   ld = (mappingtype_fromDCI == typeA) ? (NrOfSymbols + startSymbol) : NrOfSymbols;
 
-  // Section 7.4.1.1.2 in Spec 38.211
-  //For PDSCH Mapping typeB, if PDSCH duration ld <=4, only single symbol DMRS is supported
-  if (mappingtype_fromDCI == typeB && ld <= 4)
-    maxLength = 1;
-
   AssertFatal(ld > 2 && ld < 15,"Illegal NrOfSymbols according to Table 5.1.2.1-1 Spec 38.214 %d\n",ld);
   AssertFatal((NrOfSymbols + startSymbol) < 15,"Illegal S+L according to Table 5.1.2.1-1 Spec 38.214 S:%d L:%d\n",startSymbol, NrOfSymbols);
 
@@ -3076,7 +3065,8 @@ int16_t fill_dmrs_mask(NR_PDSCH_Config_t *pdsch_Config,int dmrs_TypeA_Position,i
 
   }
 
-  if (maxLength == 1) {
+  // number of front loaded symbols
+  if (length == 1) {
     row = ld - 2;
     l_prime = table_7_4_1_1_2_3_pdsch_dmrs_positions_l[row][column];
     l0 = 1 << l0;
@@ -3087,7 +3077,7 @@ int16_t fill_dmrs_mask(NR_PDSCH_Config_t *pdsch_Config,int dmrs_TypeA_Position,i
     l0 = 1<<l0 | 1<<(l0+1);
   }
 
-  LOG_D(MAC, "l0:%d, ld:%d,row:%d, column:%d, addpos:%d, maxlen:%d\n", l0, ld, row, column, dmrs_AdditionalPosition, maxLength);
+  LOG_D(MAC, "l0:%d, ld:%d,row:%d, column:%d, addpos:%d, maxlen:%d\n", l0, ld, row, column, dmrs_AdditionalPosition, length);
   AssertFatal(l_prime>=0,"ERROR in configuration.Check Time Domain allocation of this Grant. l_prime < 1. row:%d, column:%d\n", row, column);
 
   l_prime = (mappingtype_fromDCI == typeA) ? (l_prime | l0) : (l_prime << startSymbol);

openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.h

@@ -47,7 +47,7 @@ uint64_t from_nrarfcn(int nr_bandP, uint8_t scs_index, uint32_t dl_nrarfcn);
 
 uint32_t to_nrarfcn(int nr_bandP, uint64_t dl_CarrierFreq, uint8_t scs_index, uint32_t bw);
 
-int16_t fill_dmrs_mask(NR_PDSCH_Config_t *pdsch_Config,int dmrs_TypeA_Position,int NrOfSymbols,int startSymbol,int mappingtype_fromDCI);
+int16_t fill_dmrs_mask(NR_PDSCH_Config_t *pdsch_Config,int dmrs_TypeA_Position,int NrOfSymbols,int startSymbol,int mappingtype_fromDCI,int length);
 
 int is_nr_DL_slot(NR_TDD_UL_DL_ConfigCommon_t *tdd_UL_DL_ConfigurationCommon,slot_t slotP);
 
@@ -153,8 +153,6 @@ bool set_ul_ptrs_values(NR_PTRS_UplinkConfig_t *ul_ptrs_config,
                         uint8_t *reOffset, uint8_t *maxNumPorts, uint8_t *ulPower,
                         uint8_t NrOfSymbols);
 
-uint8_t get_num_dmrs_symbols(NR_PDSCH_Config_t *pdsch_Config,int dmrs_TypeA_Position,int NrOfSymbols,int startSymbol,int mappingtype);
-
 /* \brief Set the transform precoding according to 6.1.3 of 3GPP TS 38.214 version 16.3.0 Release 16
 @param    *pusch_config,   pointer to pusch config
 @param    *ubwp            pointer to uplink bwp

openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c

@@ -691,7 +691,7 @@ int8_t nr_ue_process_dci(module_id_t module_id, int cc_id, uint8_t gNB_index, fr
                                                          mac->mib->dmrs_TypeA_Position,
                                                          dlsch_config_pdu_1_0->number_symbols,
                                                          dlsch_config_pdu_1_0->start_symbol,
-                                                         mappingtype);
+                                                         mappingtype, 1);
     dlsch_config_pdu_1_0->dmrsConfigType = (mac->DLbwp[0] != NULL) ? (mac->DLbwp[0]->bwp_Dedicated->pdsch_Config->choice.setup->dmrs_DownlinkForPDSCH_MappingTypeA->choice.setup->dmrs_Type == NULL ? 0 : 1) : 0;
     /* number of DM-RS CDM groups without data according to subclause 5.1.6.2 of 3GPP TS 38.214 version 15.9.0 Release 15 */
     if (dlsch_config_pdu_1_0->number_symbols == 2)
@@ -887,12 +887,6 @@ int8_t nr_ue_process_dci(module_id_t module_id, int cc_id, uint8_t gNB_index, fr
 
     int mappingtype = pdsch_TimeDomainAllocationList ? pdsch_TimeDomainAllocationList->list.array[dci->time_domain_assignment.val]->mappingType : ((dlsch_config_pdu_1_1->start_symbol <= 3)? typeA: typeB);
 
-    /* dmrs symbol positions*/
-    dlsch_config_pdu_1_1->dlDmrsSymbPos = fill_dmrs_mask(pdsch_config,
-							 mac->scc->dmrs_TypeA_Position,
-							 dlsch_config_pdu_1_1->number_symbols,
-               dlsch_config_pdu_1_1->start_symbol,
-               mappingtype);
     dlsch_config_pdu_1_1->dmrsConfigType = mac->DLbwp[dl_bwp_id-1]->bwp_Dedicated->pdsch_Config->choice.setup->dmrs_DownlinkForPDSCH_MappingTypeA->choice.setup->dmrs_Type == NULL ? 0 : 1;
     /* TODO: fix number of DM-RS CDM groups without data according to subclause 5.1.6.2 of 3GPP TS 38.214,
              using tables 7.3.1.2.2-1, 7.3.1.2.2-2, 7.3.1.2.2-3, 7.3.1.2.2-4 of 3GPP TS 38.212 */
@@ -964,6 +958,7 @@ int8_t nr_ue_process_dci(module_id_t module_id, int cc_id, uint8_t gNB_index, fr
     uint8_t n_codewords = 1; // FIXME!!!
     long *max_length = NULL;
     long *dmrs_type = NULL;
+    dlsch_config_pdu_1_1->n_front_load_symb = 1; // default value
     if (pdsch_config->dmrs_DownlinkForPDSCH_MappingTypeA) {
       max_length = pdsch_config->dmrs_DownlinkForPDSCH_MappingTypeA->choice.setup->maxLength;
       dmrs_type = pdsch_config->dmrs_DownlinkForPDSCH_MappingTypeA->choice.setup->dmrs_Type;
@@ -1063,6 +1058,15 @@ int8_t nr_ue_process_dci(module_id_t module_id, int cc_id, uint8_t gNB_index, fr
 	dlsch_config_pdu_1_1->n_front_load_symb = table_7_3_2_3_3_4_twoCodeword[dci->antenna_ports.val][9];
       }
     }
+
+    /* dmrs symbol positions*/
+    dlsch_config_pdu_1_1->dlDmrsSymbPos = fill_dmrs_mask(pdsch_config,
+							 mac->scc->dmrs_TypeA_Position,
+							 dlsch_config_pdu_1_1->number_symbols,
+                                                         dlsch_config_pdu_1_1->start_symbol,
+                                                         mappingtype,
+                                                         dlsch_config_pdu_1_1->n_front_load_symb);
+
     /* TCI */
     if (mac->dl_config_request.dl_config_list[0].dci_config_pdu.dci_config_rel15.coreset.tci_present_in_dci == 1){
       // 0 bit if higher layer parameter tci-PresentInDCI is not enabled

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c

@@ -1063,7 +1063,7 @@ void nr_generate_Msg2(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
                                                     nr_mac->common_channels->ServingCellConfigCommon->dmrs_TypeA_Position,
                                                     nrOfSymbols,
                                                     startSymbolIndex,
-                                                    mappingtype);
+                                                    mappingtype, 1);
 
     int x_Overhead = 0;
     uint8_t tb_scaling = 0;
@@ -1258,7 +1258,7 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
                                             scc->dmrs_TypeA_Position,
                                             nrOfSymbols,
                                             startSymbolIndex,
-                                            mappingtype);
+                                            mappingtype, 1);
 
     uint16_t N_DMRS_SLOT = get_num_dmrs(dlDmrsSymbPos);
 

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_bch.c

@@ -376,7 +376,7 @@ void schedule_control_sib1(module_id_t module_id,
 
   // Calculate number of PRB_DMRS
   uint8_t N_PRB_DMRS = gNB_mac->sched_ctrlCommon->pdsch_semi_static.numDmrsCdmGrpsNoData * 6;
-  uint16_t dlDmrsSymbPos = fill_dmrs_mask(NULL, gNB_mac->common_channels->ServingCellConfigCommon->dmrs_TypeA_Position, nrOfSymbols, startSymbolIndex, mappingtype);
+  uint16_t dlDmrsSymbPos = fill_dmrs_mask(NULL, gNB_mac->common_channels->ServingCellConfigCommon->dmrs_TypeA_Position, nrOfSymbols, startSymbolIndex, mappingtype, 1);
   uint16_t dmrs_length = get_num_dmrs(dlDmrsSymbPos);
 
   LOG_D(MAC,"dlDmrsSymbPos %x\n",dlDmrsSymbPos);
@@ -613,7 +613,7 @@ void schedule_nr_sib1(module_id_t module_idP, frame_t frameP, sub_frame_t slotP)
 
       // Calculate number of PRB_DMRS
       uint8_t N_PRB_DMRS = gNB_mac->sched_ctrlCommon->pdsch_semi_static.numDmrsCdmGrpsNoData * 6;
-      uint16_t dlDmrsSymbPos = fill_dmrs_mask(NULL, gNB_mac->common_channels->ServingCellConfigCommon->dmrs_TypeA_Position, nrOfSymbols, startSymbolIndex, mappingtype);
+      uint16_t dlDmrsSymbPos = fill_dmrs_mask(NULL, gNB_mac->common_channels->ServingCellConfigCommon->dmrs_TypeA_Position, nrOfSymbols, startSymbolIndex, mappingtype, 1);
       uint16_t dmrs_length = get_num_dmrs(dlDmrsSymbPos);
 
       const uint32_t TBS = nr_compute_tbs(nr_get_Qm_dl(gNB_mac->sched_ctrlCommon->sched_pdsch.mcs, gNB_mac->sched_ctrlCommon->pdsch_semi_static.mcsTableIdx),

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c

@@ -166,10 +166,10 @@ void nr_schedule_css_dlsch_phytest(module_id_t   module_idP,
     pdsch_pdu_rel15->StartSymbolIndex = StartSymbolIndex;
     pdsch_pdu_rel15->NrOfSymbols      = NrOfSymbols;
     pdsch_pdu_rel15->dlDmrsSymbPos = fill_dmrs_mask(NULL,
-						    scc->dmrs_TypeA_Position,
-						    NrOfSymbols,
-                StartSymbolIndex,
-                mappingtype);
+                                                    scc->dmrs_TypeA_Position,
+                                                    NrOfSymbols,
+                                                    StartSymbolIndex,
+                                                    mappingtype, 1);
 
     /*
     AssertFatal(k0==0,"k0 is not zero for Initial DL BWP TimeDomain Alloc\n");

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c

@@ -200,22 +200,29 @@ void set_dl_dmrs_ports(NR_pdsch_semi_static_t *ps) {
   //     and a single front loaded symbol
   //     dmrs_ports_id is the index of Tables 7.3.1.2.2-1/2/3/4
 
+  //     number of front loaded symbols need to be consistent with maxLength
+  //     when a more complete implementation is done
+
   switch (ps->nrOfLayers) {
     case 1:
       ps->dmrs_ports_id = 0;
       ps->numDmrsCdmGrpsNoData = 1;
+      ps->frontloaded_symb = 1;
       break;
     case 2:
       ps->dmrs_ports_id = 2;
       ps->numDmrsCdmGrpsNoData = 1;
+      ps->frontloaded_symb = 1;
       break;
     case 3:
       ps->dmrs_ports_id = 9;
       ps->numDmrsCdmGrpsNoData = 2;
+      ps->frontloaded_symb = 1;
       break;
     case 4:
       ps->dmrs_ports_id = 10;
       ps->numDmrsCdmGrpsNoData = 2;
+      ps->frontloaded_symb = 1;
       break;
     default:
       AssertFatal(1==0,"Number of layers %d\n not supported or not valid\n",ps->nrOfLayers);
@@ -375,6 +382,7 @@ void nr_set_pdsch_semi_static(const NR_ServingCellConfigCommon_t *scc,
                               NR_pdsch_semi_static_t *ps)
 {
 
+  bool reset_dmrs = false;
   if (bwp &&
       bwp->bwp_Dedicated &&
       bwp->bwp_Dedicated->pdsch_Config &&
@@ -397,6 +405,7 @@ void nr_set_pdsch_semi_static(const NR_ServingCellConfigCommon_t *scc,
     pdsch_Config = NULL;
 
   if (ps->time_domain_allocation != tda) {
+    reset_dmrs = true;
     ps->time_domain_allocation = tda;
     const struct NR_PDSCH_TimeDomainResourceAllocationList *tdaList = bwp ?
       bwp->bwp_Common->pdsch_ConfigCommon->choice.setup->pdsch_TimeDomainAllocationList :
@@ -413,8 +422,6 @@ void nr_set_pdsch_semi_static(const NR_ServingCellConfigCommon_t *scc,
       ps->dmrsConfigType = NFAPI_NR_DMRS_TYPE1;
     const int startSymbolAndLength = tdaList->list.array[tda]->startSymbolAndLength;
     SLIV2SL(startSymbolAndLength, &ps->startSymbolIndex, &ps->nrOfSymbols);
-    ps->dl_dmrs_symb_pos = fill_dmrs_mask(pdsch_Config, scc->dmrs_TypeA_Position, ps->nrOfSymbols, ps->startSymbolIndex, ps->mapping_type);
-    ps->N_DMRS_SLOT = get_num_dmrs(ps->dl_dmrs_symb_pos);
   }
 
   const long dci_format = sched_ctrl->search_space->searchSpaceType->choice.ue_Specific->dci_Formats;
@@ -429,15 +436,21 @@ void nr_set_pdsch_semi_static(const NR_ServingCellConfigCommon_t *scc,
         ps->numDmrsCdmGrpsNoData = 3;
     }
     ps->dmrs_ports_id = 0;
+    ps->frontloaded_symb = 1;
   }
   else {
     if (ps->nrOfLayers != layers) {
+      reset_dmrs = true;
       ps->nrOfLayers = layers;
       set_dl_dmrs_ports(ps);
     }
   }
 
   ps->N_PRB_DMRS = ps->numDmrsCdmGrpsNoData * (ps->dmrsConfigType == NFAPI_NR_DMRS_TYPE1 ? 6 : 4);
+  if (reset_dmrs) {
+    ps->dl_dmrs_symb_pos = fill_dmrs_mask(pdsch_Config, scc->dmrs_TypeA_Position, ps->nrOfSymbols, ps->startSymbolIndex, ps->mapping_type, ps->frontloaded_symb);
+    ps->N_DMRS_SLOT = get_num_dmrs(ps->dl_dmrs_symb_pos);
+  }
 }
 
 void nr_set_pusch_semi_static(const NR_ServingCellConfigCommon_t *scc,

openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h

@@ -362,6 +362,7 @@ typedef struct NR_sched_pusch {
 typedef struct NR_pdsch_semi_static {
   int time_domain_allocation;
   uint8_t numDmrsCdmGrpsNoData;
+  uint8_t frontloaded_symb;
   int mapping_type;
   int startSymbolIndex;
   int nrOfSymbols;