check if SSB is on the sync raster for SA

openair2/GNB_APP/gnb_config.c

@@ -94,6 +94,49 @@
 extern uint16_t sf_ahead;
 int macrlc_has_f1 = 0;
 
+// synchronization raster per band tables
+// (38.101-1 Table 5.4.3.3-1 and 38.101-2 Table 5.4.3.3-1)
+// band nb, sub-carrier spacing index, Range of GSCN (First, Step size, Last)
+const uint32_t sync_raster[37][5] = {
+  {1, 0, 5279, 1, 5419},
+  {2, 0, 4829, 1, 4969},
+  {3, 0, 4517, 1, 4693},
+  {5, 0, 2177, 1, 2230},
+  {5, 1, 2183, 1, 2224},
+  {7, 0, 6554, 1, 6718},
+  {8, 0, 2318, 1, 2395},
+  {12, 0, 1828, 1, 1858},
+  {20, 0, 1982, 1, 2047},
+  {25, 0, 4829, 1, 4981},
+  {28, 0, 1901, 1, 2002},
+  {34, 0, 5030, 1, 5056},
+  {38, 0, 6431, 1, 6544},
+  {39, 0, 4706, 1, 4795},
+  {40, 0, 5756, 1, 5995},
+  {41, 0, 6246, 3, 6717},
+  {41, 1, 6254, 3, 6714},
+  {50, 0, 3584, 1, 3787},
+  {51, 0, 3572, 1, 3574},
+  {66, 0, 5279, 1, 5494},
+  {66, 1, 5285, 1, 5488},
+  {70, 0, 4993, 1, 5044},
+  {71, 0, 1547, 1, 1624},
+  {74, 0, 3692, 1, 3790},
+  {75, 0, 3584, 1, 3787},
+  {76, 0, 3572, 1, 3574},
+  {77, 1, 7711, 1, 8329},
+  {78, 1, 7711, 1, 8051},
+  {79, 1, 8480, 16, 8880},
+  {257, 3, 22388, 1, 22558},
+  {257, 4, 22390, 2, 22556},
+  {258, 3, 22257, 1, 22443},
+  {258, 4, 22258, 2, 22442},
+  {260, 3, 22995, 1, 23166},
+  {260, 4, 22996, 2, 23164},
+  {261, 3, 22446, 1, 22492},
+  {261, 4, 22446, 2, 22490},
+};
+
 extern int config_check_band_frequencies(int ind, int16_t band, uint64_t downlink_frequency,
                                          int32_t uplink_frequency_offset, uint32_t  frame_type);
 
@@ -1073,7 +1116,59 @@ void config_security(gNB_RRC_INST *rrc)
   }
 }
 
-void RCconfig_NRRRC(MessageDef *msg_p, uint32_t i, gNB_RRC_INST *rrc) {
+// Section 5.4.3 of 38.101-1 and -2
+void check_ssb_raster(long absolutefreqssb, int band, int scs)
+{
+  int start_GSCN = 0, step_GSCN = 0, end_GSCN = 0;
+  for (int i = 0; i < sizeof(sync_raster) / 20; i++) {
+    if (sync_raster[i][0] == band &&
+        sync_raster[i][1] == scs) {
+      start_GSCN = sync_raster[i][2];
+      step_GSCN = sync_raster[i][3];
+      end_GSCN = sync_raster[i][4];
+      break;
+    }
+  }
+  AssertFatal(start_GSCN != 0, "Couldn't find band %d with SCS %d\n", band, scs);
+  uint64_t freq = from_nrarfcn(band, scs, absolutefreqssb);
+  int GSCN;
+  if (freq <= 3000000000) {
+    int N = 0;
+    int M = 0;
+    for (int k = 0; k < 3; k++) {
+      M = (k << 1) + 1;
+      if ((freq - M * 50000) % 1200000) {
+        N = (freq - M * 50000) / 1200000;
+        break;
+      }
+    }
+    AssertFatal(N != 0, "absoluteFrequencySSB %ld (%lu) not on the synchronization raster (N * 1200kHz + M * 50 kHz)\n",
+                absolutefreqssb, freq);
+    GSCN = (3 * N) + (M - 3) / 2;
+  }
+  else if (freq <= 24250000000) {
+    AssertFatal((freq - 3000000000) % 1440000 == 0,
+                "absoluteFrequencySSB %ld (%lu) not on the synchronization raster (3000 MHz + N * 1.44 MHz)\n",
+                absolutefreqssb, freq);
+    GSCN = ((freq - 3000000000) / 1440000) + 7499;
+  }
+  else {
+    AssertFatal((freq - 24250080000) % 17280000 == 0,
+                "absoluteFrequencySSB %ld (%lu) not on the synchronization raster (24250.08 MHz + N * 17.28 MHz)\n",
+                absolutefreqssb, freq);
+    GSCN = ((freq - 24250080000) / 17280000) + 22256;
+  }
+  AssertFatal(GSCN >= start_GSCN && GSCN <= end_GSCN,
+              "GSCN %d corresponding to absoluteFrequencySSB %ld does not belong to GSCN range for band %d\n",
+              GSCN, absolutefreqssb, band);
+  int rel_GSCN = GSCN - start_GSCN;
+  AssertFatal(rel_GSCN % step_GSCN == 0,
+              "GSCN %d corresponding to absoluteFrequencySSB %ld not in accordance with GSCN step for band %d\n",
+               GSCN, absolutefreqssb, band);
+}
+
+void RCconfig_NRRRC(MessageDef *msg_p, uint32_t i, gNB_RRC_INST *rrc)
+{
 
   int num_gnbs = 0;
   char aprefix[MAX_OPTNAME_SIZE*2 + 8];
@@ -1106,11 +1201,10 @@ void RCconfig_NRRRC(MessageDef *msg_p, uint32_t i, gNB_RRC_INST *rrc) {
   num_gnbs = GNBSParams[GNB_ACTIVE_GNBS_IDX].numelt;
   AssertFatal (i<num_gnbs,"Failed to parse config file no %uth element in %s \n",i, GNB_CONFIG_STRING_ACTIVE_GNBS);
 
-  if (num_gnbs>0) {
+  if (num_gnbs > 0) {
 
     // Output a list of all gNBs. ////////// Identification parameters
     config_getlist( &GNBParamList,GNBParams,sizeof(GNBParams)/sizeof(paramdef_t),NULL); 
-    
     if (GNBParamList.paramarray[i][GNB_GNB_ID_IDX].uptr == NULL) {
     // Calculate a default gNB ID
       if (get_softmodem_params()->sa) { 
@@ -1129,7 +1223,7 @@ void RCconfig_NRRRC(MessageDef *msg_p, uint32_t i, gNB_RRC_INST *rrc) {
     config_getlist(&SCCsParamList, NULL, 0, aprefix);
     if (SCCsParamList.numelt > 0) {    
       sprintf(aprefix, "%s.[%i].%s.[%i]", GNB_CONFIG_STRING_GNB_LIST,0,GNB_CONFIG_STRING_SERVINGCELLCONFIGCOMMON, 0);
-      config_get( SCCsParams,sizeof(SCCsParams)/sizeof(paramdef_t),aprefix);  
+      config_get(SCCsParams,sizeof(SCCsParams) / sizeof(paramdef_t), aprefix);
       LOG_I(RRC,"Read in ServingCellConfigCommon (PhysCellId %d, ABSFREQSSB %d, DLBand %d, ABSFREQPOINTA %d, DLBW %d,RACH_TargetReceivedPower %d\n",
 	    (int)*scc->physCellId,
 	    (int)*scc->downlinkConfigCommon->frequencyInfoDL->absoluteFrequencySSB,
@@ -1137,7 +1231,12 @@ void RCconfig_NRRRC(MessageDef *msg_p, uint32_t i, gNB_RRC_INST *rrc) {
 	    (int)scc->downlinkConfigCommon->frequencyInfoDL->absoluteFrequencyPointA,
 	    (int)scc->downlinkConfigCommon->frequencyInfoDL->scs_SpecificCarrierList.list.array[0]->carrierBandwidth,
 	    (int)scc->uplinkConfigCommon->initialUplinkBWP->rach_ConfigCommon->choice.setup->rach_ConfigGeneric.preambleReceivedTargetPower);
-      fix_scc(scc,ssb_bitmap);
+      // SSB of the PCell is always on the sync raster
+      if (get_softmodem_params()->sa)
+        check_ssb_raster(*scc->downlinkConfigCommon->frequencyInfoDL->absoluteFrequencySSB,
+                         *scc->downlinkConfigCommon->frequencyInfoDL->frequencyBandList.list.array[0],
+                         *scc->ssbSubcarrierSpacing);
+      fix_scc(scc, ssb_bitmap);
     }
 
     sprintf(aprefix, "%s.[%i]", GNB_CONFIG_STRING_GNB_LIST, 0);