Increase SRS periodicity to get higher bitrate

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_srs.c

@@ -175,7 +175,7 @@ void nr_schedule_srs(int module_id, frame_t frame) {
 
       // Check if UE will transmit the SRS in this frame
       if ( ((frame - offset/n_slots_frame)*n_slots_frame)%period == 0) {
-        LOG_D(NR_MAC,"(%d.%d) Scheduling SRS reception\n", frame, offset%n_slots_frame);
+        LOG_D(NR_MAC,"Scheduling SRS reception for %d.%d\n", frame, offset%n_slots_frame);
         nr_fill_nfapi_srs(module_id, CC_id, UE_id, offset%n_slots_frame, srs_resource);
         sched_ctrl->sched_srs.frame = frame;
         sched_ctrl->sched_srs.slot = offset%n_slots_frame;

openair2/RRC/NR/MESSAGES/asn1_msg.c

@@ -1021,8 +1021,8 @@ void fill_initial_SpCellConfig(rnti_t rnti,
 
   // This assert will never happen in the current implementation because NUMBER_OF_UE_MAX = 4.
   // However, if in the future NUMBER_OF_UE_MAX is increased, it will be necessary to improve the allocation of SRS resources,
-  // where the startPosition = 1, 2 or 3 and sl40 = 7, 17, 27 or 37 only give us 12 different allocations.
-  AssertFatal(uid>=0 && uid<12, "gNB cannot allocate the SRS resources\n");
+  // where the startPosition = 2 or 3 and sl160 = 17, 17, 27 ... 157 only give us 30 different allocations.
+  AssertFatal(uid>=0 && uid<30, "gNB cannot allocate the SRS resources\n");
 
   int curr_bwp = NRRIV2BW(scc->downlinkConfigCommon->initialDownlinkBWP->genericParameters.locationAndBandwidth,MAX_BWP_SIZE);
   SpCellConfig->servCellIndex = NULL;
@@ -1182,7 +1182,7 @@ void fill_initial_SpCellConfig(rnti_t rnti,
   srs_res0->transmissionComb.choice.n2=calloc(1,sizeof(*srs_res0->transmissionComb.choice.n2));
   srs_res0->transmissionComb.choice.n2->combOffset_n2=0;
   srs_res0->transmissionComb.choice.n2->cyclicShift_n2=0;
-  srs_res0->resourceMapping.startPosition = 1 + uid%3;
+  srs_res0->resourceMapping.startPosition = 2 + uid%2;
   srs_res0->resourceMapping.nrofSymbols=NR_SRS_Resource__resourceMapping__nrofSymbols_n1;
   srs_res0->resourceMapping.repetitionFactor=NR_SRS_Resource__resourceMapping__repetitionFactor_n1;
   srs_res0->freqDomainPosition=0;
@@ -1197,8 +1197,8 @@ void fill_initial_SpCellConfig(rnti_t rnti,
   if(carrier->do_SRS) {
     srs_res0->resourceType.present= NR_SRS_Resource__resourceType_PR_periodic;
     srs_res0->resourceType.choice.periodic=calloc(1,sizeof(*srs_res0->resourceType.choice.periodic));
-    srs_res0->resourceType.choice.periodic->periodicityAndOffset_p.present = NR_SRS_PeriodicityAndOffset_PR_sl40;
-    srs_res0->resourceType.choice.periodic->periodicityAndOffset_p.choice.sl40 = 7 + (uid/3)*10; // 7/17/27/37 are mixed slots
+    srs_res0->resourceType.choice.periodic->periodicityAndOffset_p.present = NR_SRS_PeriodicityAndOffset_PR_sl160;
+    srs_res0->resourceType.choice.periodic->periodicityAndOffset_p.choice.sl160 = 17 + (uid>1)*10; // 17/17/.../147/157 are mixed slots
   } else {
     srs_res0->resourceType.present= NR_SRS_Resource__resourceType_PR_aperiodic;
     srs_res0->resourceType.choice.aperiodic=calloc(1,sizeof(*srs_res0->resourceType.choice.aperiodic));