Use command line option for sell search

There is already a command line option called 'ue-scan-carrier' which
seemed to blindly look for SSB by changing the center frequency by
+/-100Hz if the previous attempt failed. This is probably copied from
LTE and is not suitable for NR. This commit uses this option to either
1. Perform initial sync on one GSCN if the SSB position if known
2. Or scan the all GSCN (if the SSB postion is unknown)

Also, the following is done for re-synchronization
1. Scan all GSCN when UE comes back from IDLE state
2. Scan one GSCN when UE does re-estabishment

Removed dependency of lte-softmodem.h in nr-softmodem.c.
CONFIG_HLP_UESCAN is declared also in lte-softmodem.h.

executables/nr-softmodem-common.h

@@ -47,7 +47,7 @@
 #define CONFIG_HLP_UETXG         "set UE TX gain\n"
 #define CONFIG_HLP_UENANTR       "set UE number of rx antennas\n"
 #define CONFIG_HLP_UENANTT       "set UE number of tx antennas\n"
-#define CONFIG_HLP_UESCAN        "set UE to scan around carrier\n"
+#define CONFIG_HLP_UESCAN "set UE to scan all possible GSCN in current bandwidth\n"
 #define CONFIG_HLP_UEFO          "set UE to enable estimation and compensation of frequency offset\n"
 #define CONFIG_HLP_DUMPFRAME     "dump UE received frame to rxsig_frame0.dat and exit\n"
 #define CONFIG_HLP_DLSHIFT       "dynamic shift for LLR compuation for TM3/4 (default 0)\n"

executables/nr-softmodem.c

@@ -49,7 +49,6 @@
 #include "PHY_INTERFACE/phy_interface_vars.h"
 #include "gnb_config.h"
 #include "SIMULATION/TOOLS/sim.h"
-#include "executables/lte-softmodem.h"
 
 #ifdef SMBV
 #include "PHY/TOOLS/smbv.h"
@@ -604,6 +603,7 @@ static void initialize_agent(ngran_node_t node_type, e2_agent_args_t oai_args)
 }
 #endif
 
+void init_eNB_afterRU(void);
 configmodule_interface_t *uniqCfg = NULL;
 int main( int argc, char **argv ) {
   int ru_id, CC_id = 0;

executables/nr-ue.c

@@ -348,7 +348,13 @@ static void *NRUE_phy_stub_standalone_pnf_task(void *arg)
  * \param arg is a pointer to a \ref PHY_VARS_NR_UE structure.
  */
 
-typedef nr_rxtx_thread_data_t syncData_t;
+typedef struct {
+  PHY_VARS_NR_UE *UE;
+  UE_nr_rxtx_proc_t proc;
+  nr_gscn_info_t gscnInfo[MAX_GSCN_BAND];
+  int numGscn;
+  int rx_offset;
+} syncData_t;
 
 static void UE_synch(void *arg) {
   syncData_t *syncD=(syncData_t *) arg;
@@ -431,7 +437,7 @@ static void UE_synch(void *arg) {
 
       uint64_t dl_carrier, ul_carrier;
       nr_get_carrier_frequencies(UE, &dl_carrier, &ul_carrier);
-      nr_initial_sync_t ret = nr_initial_sync(&syncD->proc, UE, 2, get_softmodem_params()->sa);
+      nr_initial_sync_t ret = nr_initial_sync(&syncD->proc, UE, 2, get_softmodem_params()->sa, syncD->gscnInfo, syncD->numGscn);
       if (ret.cell_detected) {
         syncD->rx_offset = ret.rx_offset;
         freq_offset = UE->common_vars.freq_offset; // frequency offset computed with pss in initial sync
@@ -451,24 +457,7 @@ static void UE_synch(void *arg) {
               openair0_cfg[UE->rf_map.card].tx_freq[0]);
 
         UE->rfdevice.trx_set_freq_func(&UE->rfdevice,&openair0_cfg[0]);
-        if (UE->UE_scan_carrier == 1)
-          UE->UE_scan_carrier = 0;
-        else
-          UE->is_synchronized = 1;
-      } else {
-        if (UE->UE_scan_carrier == 1) {
-
-          if (freq_offset >= 0)
-            freq_offset += 100;
-
-          freq_offset *= -1;
-
-          nr_rf_card_config_freq(&openair0_cfg[UE->rf_map.card], ul_carrier, dl_carrier, freq_offset);
-
-          LOG_I(PHY, "Initial sync failed: trying carrier off %d Hz\n", freq_offset);
-
-          UE->rfdevice.trx_set_freq_func(&UE->rfdevice,&openair0_cfg[0]);
-        }
+        UE->is_synchronized = 1;
       }
       break;
 
@@ -601,6 +590,7 @@ static int UE_dl_preprocessing(PHY_VARS_NR_UE *UE, const UE_nr_rxtx_proc_t *proc
     // Start synchronization with a target gNB
     if (UE->synch_request.received_synch_request == 1) {
       UE->is_synchronized = 0;
+      UE->UE_scan_carrier = UE->synch_request.synch_req.ssb_bw_scan;
       UE->target_Nid_cell = UE->synch_request.synch_req.target_Nid_cell;
       clean_UE_harq(UE);
       UE->synch_request.received_synch_request = 0;
@@ -818,6 +808,20 @@ void *UE_thread(void *arg)
       readFrame(UE, &sync_timestamp, false);
       notifiedFIFO_elt_t *Msg = newNotifiedFIFO_elt(sizeof(syncData_t), 0, &nf, UE_synch);
       syncData_t *syncMsg = (syncData_t *)NotifiedFifoData(Msg);
+      NR_DL_FRAME_PARMS *fp = &UE->frame_parms;
+      if (UE->UE_scan_carrier) {
+        // Get list of GSCN in this band for UE's bandwidth and center frequency.
+        LOG_W(PHY, "UE set to scan all GSCN in current bandwidth\n");
+        syncMsg->numGscn =
+            get_scan_ssb_first_sc(fp->dl_CarrierFreq, fp->N_RB_DL, fp->nr_band, fp->numerology_index, syncMsg->gscnInfo);
+      } else {
+        LOG_W(PHY, "SSB position provided\n");
+        nr_gscn_info_t *g = syncMsg->gscnInfo;
+        g->ssbFirstSC = fp->ssb_start_subcarrier;
+        g->gscn = 0;
+        g->ssRef = 0;
+        syncMsg->numGscn = 1;
+      }
       syncMsg->UE = UE;
       memset(&syncMsg->proc, 0, sizeof(syncMsg->proc));
       pushTpool(&(get_nrUE_params()->Tpool), Msg);

nfapi/open-nFAPI/nfapi/public_inc/fapi_nr_ue_interface.h

@@ -688,6 +688,7 @@ typedef struct
 
 typedef struct {
   int16_t target_Nid_cell;
+  bool ssb_bw_scan;
 } fapi_nr_synch_request_t;
 
 typedef struct {

openair1/PHY/NR_UE_TRANSPORT/nr_initial_sync.c

@@ -293,13 +293,15 @@ void nr_scan_ssb(void *arg)
   }
 }
 
-nr_initial_sync_t nr_initial_sync(UE_nr_rxtx_proc_t *proc, PHY_VARS_NR_UE *ue, int n_frames, int sa)
+nr_initial_sync_t nr_initial_sync(UE_nr_rxtx_proc_t *proc,
+                                  PHY_VARS_NR_UE *ue,
+                                  int n_frames,
+                                  int sa,
+                                  nr_gscn_info_t gscnInfo[MAX_GSCN_BAND],
+                                  int numGscn)
 {
   NR_DL_FRAME_PARMS *fp = &ue->frame_parms;
 
-  // Get list of GSCN in this band, current UE's bandwidth and center frequency.
-  nr_gscn_info_t gscnInfo[MAX_GSCN_BAND];
-  int numScans = get_scan_ssb_first_sc(fp->dl_CarrierFreq, fp->N_RB_DL, fp->nr_band, fp->numerology_index, gscnInfo);
   notifiedFIFO_t nf;
   initNotifiedFIFO(&nf);
 
@@ -308,8 +310,8 @@ nr_initial_sync_t nr_initial_sync(UE_nr_rxtx_proc_t *proc, PHY_VARS_NR_UE *ue, i
         "Starting cell search with center freq: %ld, bandwidth: %d. Scanning for %d number of GSCN.\n",
         fp->dl_CarrierFreq,
         fp->N_RB_DL,
-        numScans);
-  for (int s = 0; s < numScans; s++) {
+        numGscn);
+  for (int s = 0; s < numGscn; s++) {
     notifiedFIFO_elt_t *req = newNotifiedFIFO_elt(sizeof(nr_ue_ssb_scan_t), gscnInfo[s].gscn, &nf, &nr_scan_ssb);
     nr_ue_ssb_scan_t *ssbInfo = (nr_ue_ssb_scan_t *)NotifiedFifoData(req);
     ssbInfo->gscnInfo = gscnInfo[s];
@@ -334,7 +336,7 @@ nr_initial_sync_t nr_initial_sync(UE_nr_rxtx_proc_t *proc, PHY_VARS_NR_UE *ue, i
 
   // Collect the scan results
   nr_ue_ssb_scan_t res = {0};
-  while (numScans) {
+  while (numGscn) {
     notifiedFIFO_elt_t *req = pullTpool(&nf, &get_nrUE_params()->Tpool);
     nr_ue_ssb_scan_t *ssbInfo = (nr_ue_ssb_scan_t *)NotifiedFifoData(req);
     if (ssbInfo->syncRes.cell_detected) {
@@ -354,7 +356,7 @@ nr_initial_sync_t nr_initial_sync(UE_nr_rxtx_proc_t *proc, PHY_VARS_NR_UE *ue, i
     }
     free(ssbInfo->rxdata);
     delNotifiedFIFO_elt(req);
-    numScans--;
+    numGscn--;
   }
 
   // Set globals based on detected cell
@@ -446,15 +448,6 @@ nr_initial_sync_t nr_initial_sync(UE_nr_rxtx_proc_t *proc, PHY_VARS_NR_UE *ue, i
 
     if (res.syncRes.cell_detected) {
       LOG_I(PHY, "[UE%d] In synch, rx_offset %d samples\n", ue->Mod_id, res.syncRes.rx_offset);
-      if (ue->UE_scan_carrier == 0) {
-#if UE_AUTOTEST_TRACE
-      LOG_I(PHY,
-            "[UE  %d] AUTOTEST Cell Sync : rx_offset %d, freq_offset %d \n",
-            ue->Mod_id,
-            ue->rx_offset,
-            ue->common_vars.freq_offset);
-#endif
-      }
       LOG_I(PHY, "[UE %d] Measured Carrier Frequency offset %d Hz\n", ue->Mod_id, res.freqOffset);
     } else {
 #ifdef DEBUG_INITIAL_SYNC

openair1/PHY/NR_UE_TRANSPORT/nr_transport_proto_ue.h

@@ -325,7 +325,12 @@ int dump_ue_stats(PHY_VARS_NR_UE *phy_vars_ue,
 @param n_frames
   @param sa current running mode
 */
-nr_initial_sync_t nr_initial_sync(UE_nr_rxtx_proc_t *proc, PHY_VARS_NR_UE *phy_vars_ue, int n_frames, int sa);
+nr_initial_sync_t nr_initial_sync(UE_nr_rxtx_proc_t *proc,
+                                  PHY_VARS_NR_UE *phy_vars_ue,
+                                  int n_frames,
+                                  int sa,
+                                  nr_gscn_info_t gscnInfo[MAX_GSCN_BAND],
+                                  int numGscn);
 
 /*!
   \brief This function gets the carrier frequencies either from FP or command-line-set global variables, depending on the

openair2/LAYER2/NR_MAC_UE/config_ue.c

@@ -1420,6 +1420,7 @@ void nr_rrc_mac_config_req_reset(module_id_t module_id,
                                  NR_UE_MAC_reset_cause_t cause)
 {
   NR_UE_MAC_INST_t *mac = get_mac_inst(module_id);
+  fapi_nr_synch_request_t sync_req = {.target_Nid_cell = -1, .ssb_bw_scan = true};
   switch (cause) {
     case GO_TO_IDLE:
       reset_ra(mac, true);
@@ -1427,7 +1428,7 @@ void nr_rrc_mac_config_req_reset(module_id_t module_id,
       nr_ue_init_mac(mac);
       nr_ue_mac_default_configs(mac);
       // new sync but no target cell id -> -1
-      nr_ue_send_synch_request(mac, module_id, 0, -1);
+      nr_ue_send_synch_request(mac, module_id, 0, &sync_req);
       break;
     case DETACH:
       LOG_A(NR_MAC, "Received detach indication\n");
@@ -1448,7 +1449,9 @@ void nr_rrc_mac_config_req_reset(module_id_t module_id,
       nr_ue_reset_sync_state(mac);
       release_mac_configuration(mac, cause);
       // new sync with old cell ID (re-establishment on the same cell)
-      nr_ue_send_synch_request(mac, module_id, 0, mac->physCellId);
+      sync_req.target_Nid_cell = mac->physCellId;
+      sync_req.ssb_bw_scan = false;
+      nr_ue_send_synch_request(mac, module_id, 0, &sync_req);
       break;
     default:
       AssertFatal(false, "Invalid MAC reset cause %d\n", cause);

openair2/LAYER2/NR_MAC_UE/mac_proto.h

@@ -295,7 +295,7 @@ void prepare_msg4_feedback(NR_UE_MAC_INST_t *mac, int pid, int ack_nack);
 void configure_initial_pucch(PUCCH_sched_t *pucch, int res_ind);
 void release_PUCCH_SRS(NR_UE_MAC_INST_t *mac);
 void nr_ue_reset_sync_state(NR_UE_MAC_INST_t *mac);
-void nr_ue_send_synch_request(NR_UE_MAC_INST_t *mac, module_id_t module_id, int cc_id, int cell_id);
+void nr_ue_send_synch_request(NR_UE_MAC_INST_t *mac, module_id_t module_id, int cc_id, const fapi_nr_synch_request_t *sync_req);
 
 /**
  * @brief   Get UE sync state

openair2/LAYER2/NR_MAC_UE/main_ue_nr.c

@@ -98,12 +98,12 @@ void nr_ue_mac_default_configs(NR_UE_MAC_INST_t *mac)
   mac->scheduling_info.prohibitPHR_Timer = NR_PHR_Config__phr_ProhibitTimer_sf10;
 }
 
-void nr_ue_send_synch_request(NR_UE_MAC_INST_t *mac, module_id_t module_id, int cc_id, int cell_id)
+void nr_ue_send_synch_request(NR_UE_MAC_INST_t *mac, module_id_t module_id, int cc_id, const fapi_nr_synch_request_t *sync_req)
 {
   // Sending to PHY a request to resync
   mac->synch_request.Mod_id = module_id;
   mac->synch_request.CC_id = cc_id;
-  mac->synch_request.synch_req.target_Nid_cell = cell_id;
+  mac->synch_request.synch_req = *sync_req;
   mac->if_module->synch_request(&mac->synch_request);
 }