ue mac changes for long prach

Fix bug in talbe 38.211 6.3.3.2-1 for FR2.

openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.c

@@ -701,51 +701,33 @@ uint16_t get_NCS(uint8_t index, uint16_t format0, uint8_t restricted_set_config)
   }
 }
 
-//from 38.211 Table 6.3.3.2-1
-static const int16_t N_RA_RB[16] = {6, 3, 2, 24, 12, 6, 12, 6, 3, 24, 12, 6, 12, 6, 24, 12};
-
+//from 38.211 Table 6.3.3.2-1            // 15  30 60 120 240 480
+static const unsigned int N_RA_RB[6][6] = {{12,  6, 3, -1, -1, -1},
+                                           {24, 12, 6, -1, -1, -1},
+                                           {-1, -1, 12, 6, -1, -1},
+                                           {-1, -1, 24, 12, 3, 2},
+                                           // L839
+                                           {6,   3, 2, -1, -1, -1},
+                                           {24, 12, 6, -1, -1, -1}};
 /* Function to get number of RBs required for prach occasion based on
  * 38.211 Table 6.3.3.2-1 */
-int16_t get_N_RA_RB (int delta_f_RA_PRACH, int delta_f_PUSCH)
+unsigned int get_N_RA_RB(const unsigned int delta_f_RA_PRACH, const unsigned int delta_f_PUSCH)
 {
-  int8_t index = 0;
-  switch(delta_f_RA_PRACH) {
-    case 0 :
-      index = 6;
-      if (delta_f_PUSCH == 0)
-        index += 0;
-      else if(delta_f_PUSCH == 1)
-        index += 1;
-      else
-        index += 2;
-      break;
-    case 1 :
-      index = 9;
-      if (delta_f_PUSCH == 0)
-        index += 0;
-      else if(delta_f_PUSCH == 1)
-        index += 1;
-      else
-        index += 2;
-      break;
-    case 2 :
-      index = 11;
-      if (delta_f_PUSCH == 2)
-        index += 0;
-      else
-        index += 1;
-      break;		
-    case 3:
-      index = 13;
-      if (delta_f_PUSCH == 2)
-        index += 0;
-      else
-        index += 1;
-      break;
-    default : index = 10;/*30khz prach scs and 30khz pusch scs*/
-  }
-  return N_RA_RB[index];
-}	
+  DevAssert(delta_f_PUSCH < 6);
+  DevAssert(delta_f_RA_PRACH < 6);
+  unsigned int n_rb;
+  n_rb = N_RA_RB[delta_f_RA_PRACH][delta_f_PUSCH];
+  DevAssert(n_rb != -1);
+  return n_rb;
+}
+
+// frome Table 6.3.3.1-1
+unsigned int get_delta_f_RA_long(const unsigned int format)
+{
+  DevAssert(format < 4);
+  return (format == 3) ? 5 : 4;
+}
+
 // Table 6.3.3.2-2: Random access configurations for FR1 and paired spectrum/supplementary uplink
 // the column 5, (SFN_nbr is a bitmap where we set bit to '1' in the position of the subframe where the RACH can be sent.
 // E.g. in row 4, and column 5 we have set value 512 ('1000000000') which means RACH can be sent at subframe 9.

openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.h

@@ -262,7 +262,8 @@ uint16_t compute_pucch_prb_size(uint8_t format,
 float get_max_code_rate(NR_PUCCH_MaxCodeRate_t *maxCodeRate);
 int get_f3_dmrs_symbols(NR_PUCCH_Resource_t *pucchres, NR_PUCCH_Config_t *pucch_Config);
 
-int16_t get_N_RA_RB (int delta_f_RA_PRACH,int delta_f_PUSCH);
+unsigned int get_delta_f_RA_long(const unsigned int format);
+unsigned int get_N_RA_RB(const unsigned int delta_f_RA_PRACH, const unsigned int delta_f_PUSCH);
 
 void find_period_offset_SR(const NR_SchedulingRequestResourceConfig_t *SchedulingReqRec, int *period, int *offset);
 

openair2/LAYER2/NR_MAC_UE/config_ue.c

@@ -190,7 +190,7 @@ static void config_common_ue_sa(NR_UE_MAC_INST_t *mac, NR_ServingCellConfigCommo
     int config_index = rach_ConfigCommon->rach_ConfigGeneric.prach_ConfigurationIndex;
     const int64_t *prach_config_info_p = get_prach_config_info(mac->frequency_range, config_index, frame_type);
     int format = prach_config_info_p[0];
-    cfg->prach_config.prach_sub_c_spacing = format == 3 ? 5 : 4;
+    cfg->prach_config.prach_sub_c_spacing = get_delta_f_RA_long(format);
   }
 
   cfg->prach_config.restricted_set_config = rach_ConfigCommon->restrictedSetConfig;

openair2/LAYER2/NR_MAC_UE/nr_ra_procedures.c

@@ -76,9 +76,18 @@ void init_RA(NR_UE_MAC_INST_t *mac,
   fapi_nr_config_request_t *cfg = &mac->phy_config.config_req;
 
   prach_resources->RA_PREAMBLE_BACKOFF = 0;
-  AssertFatal(nr_rach_ConfigCommon && nr_rach_ConfigCommon->msg1_SubcarrierSpacing,
-              "Cannot handle yet the scenario without msg1_SubcarrierSpacing (L839)\n");
-  NR_SubcarrierSpacing_t prach_scs = *nr_rach_ConfigCommon->msg1_SubcarrierSpacing;
+  NR_SubcarrierSpacing_t prach_scs;
+  int scs_for_pcmax; // for long prach the UL BWP SCS is used for calculating RA_PCMAX
+  if (nr_rach_ConfigCommon && nr_rach_ConfigCommon->msg1_SubcarrierSpacing) {
+    prach_scs = *nr_rach_ConfigCommon->msg1_SubcarrierSpacing;
+    scs_for_pcmax = prach_scs;
+  } else {
+    const unsigned int index = rach_ConfigGeneric->prach_ConfigurationIndex;
+    const unsigned int unpaired = mac->phy_config.config_req.cell_config.frame_duplex_type;
+    const unsigned int format = get_format0(index, unpaired, mac->frequency_range);
+    prach_scs = get_delta_f_RA_long(format);
+    scs_for_pcmax = mac->current_UL_BWP->scs;
+  }
   int n_prbs = get_N_RA_RB(prach_scs, mac->current_UL_BWP->scs);
   int start_prb = rach_ConfigGeneric->msg1_FrequencyStart + mac->current_UL_BWP->BWPStart;
   // PRACH shall be as specified for QPSK modulated DFT-s-OFDM of equivalent RB allocation (38.101-1)
@@ -89,8 +98,8 @@ void init_RA(NR_UE_MAC_INST_t *mac,
                                            mac->current_UL_BWP->channel_bandwidth,
                                            2,
                                            false,
-                                           prach_scs,
-                                           cfg->carrier_config.dl_grid_size[prach_scs],
+                                           scs_for_pcmax,
+                                           cfg->carrier_config.dl_grid_size[scs_for_pcmax],
                                            true,
                                            n_prbs,
                                            start_prb);