use FAPI field to set SSB case from upper layers

common/utils/nr/nr_common.c

@@ -152,6 +152,32 @@ int get_smallest_supported_bandwidth_index(int scs, frequency_range_t frequency_
   return -1; // not found
 }
 
+// Table 5.4.3.3-1 38-101
+uint8_t set_ssb_case(int scs, int nr_band)
+{
+  uint8_t ssb_case = 0;
+  switch (scs) {
+    case 0:
+      ssb_case = 0; // case A
+      break;
+    case 1:
+      if (nr_band == 5 || nr_band == 24 || nr_band == 66 || nr_band == 255)
+        ssb_case = 1; // case B
+      else
+        ssb_case = 2; // case C
+      break;
+    case 3:
+      ssb_case = 3; // case D
+      break;
+    case 4:
+      ssb_case = 4; // case E
+      break;
+    default:
+      AssertFatal(false, "Invalid sub-carrier spacing for SSB\n");
+  }
+  return ssb_case;
+}
+
 // Table 5.2-1 NR operating bands in FR1 & FR2 (3GPP TS 38.101) (Rel.17)
 // Table 5.4.2.3-1 Applicable NR-ARFCN per operating band in FR1 & FR2 (3GPP TS 38.101)
 // Notes:

common/utils/nr/nr_common.h

@@ -288,7 +288,7 @@ static inline void warn_higher_threequarter_fs(const int n_rb, const int mu)
 
 uint64_t from_nrarfcn(int nr_bandP, uint8_t scs_index, uint32_t dl_nrarfcn);
 uint32_t to_nrarfcn(uint64_t dl_CarrierFreq);
-
+uint8_t set_ssb_case(int scs, int nr_band);
 int cce_to_reg_interleaving(const int R, int k, int n_shift, const int C, int L, const int N_regs);
 int get_SLIV(uint8_t S, uint8_t L);
 void get_coreset_rballoc(const uint8_t *FreqDomainResource, int *n_rb, int *rb_offset);