brute force ssb detection

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

@@ -75,7 +75,7 @@ typedef struct
 
   // These TLVs are used by the VNF to configure the RF in the PNF
   // nfapi_uint16_tlv_t max_transmit_power;
-  nfapi_uint16_tlv_t nrarfcn;
+  nfapi_uint32_tlv_t nrarfcn;
 
   // nfapi_nmm_frequency_bands_t nmm_gsm_frequency_bands;
   // nfapi_nmm_frequency_bands_t nmm_umts_frequency_bands;

openair1/PHY/INIT/nr_init.c

@@ -363,7 +363,7 @@ void nr_phy_config_request_sim(PHY_VARS_gNB *gNB,int N_RB_DL,int N_RB_UL,int mu,
   NR_DL_FRAME_PARMS *fp = &gNB->frame_parms;
   nfapi_nr_config_request_t *gNB_config = &gNB->gNB_config;
   //overwrite for new NR parameters
-  gNB_config->nfapi_config.rf_bands.rf_band[0] = 5;
+  gNB_config->nfapi_config.rf_bands.rf_band[0] = 78;
   gNB_config->nfapi_config.nrarfcn.value = 620000;
   gNB_config->subframe_config.numerology_index_mu.value = mu;
   gNB_config->subframe_config.duplex_mode.value = TDD;
@@ -377,12 +377,13 @@ void nr_phy_config_request_sim(PHY_VARS_gNB *gNB,int N_RB_DL,int N_RB_UL,int mu,
   gNB_config->sch_config.ssb_scg_position_in_burst.value=position_in_burst;
 
   gNB->mac_enabled     = 1;
-  fp->dl_CarrierFreq = from_nrarfcn(gNB_config->nfapi_config.rf_bands.rf_band[0],gNB_config->nfapi_config.nrarfcn.value);
-  fp->ul_CarrierFreq = fp->dl_CarrierFreq - (get_uldl_offset(gNB_config->nfapi_config.rf_bands.rf_band[0])*100000);
+  fp->dl_CarrierFreq = 3500000000;//from_nrarfcn(gNB_config->nfapi_config.rf_bands.rf_band[0],gNB_config->nfapi_config.nrarfcn.value);
+  fp->ul_CarrierFreq = 3500000000;//fp->dl_CarrierFreq - (get_uldl_offset(gNB_config->nfapi_config.rf_bands.rf_band[0])*100000);
   fp->threequarter_fs                    = 0;
   nr_init_frame_parms(gNB_config, fp);
   gNB->configured                                   = 1;
   LOG_I(PHY,"gNB configured\n");
+
 }
 
 

openair1/PHY/MODULATION/slot_fep_nr.c

@@ -45,8 +45,16 @@ int nr_slot_fep(PHY_VARS_NR_UE *ue,
   NR_UE_COMMON *common_vars   = &ue->common_vars;
   unsigned char aa;
   unsigned char symbol = l;//+((7-frame_parms->Ncp)*(Ns&1)); ///symbol within sub-frame
-  unsigned int nb_prefix_samples = (no_prefix ? 0 : frame_parms->nb_prefix_samples);
-  unsigned int nb_prefix_samples0 = (no_prefix ? 0 : frame_parms->nb_prefix_samples0);
+  unsigned int nb_prefix_samples;
+  unsigned int nb_prefix_samples0;
+  if (ue->is_synchronized) {
+    nb_prefix_samples = (no_prefix ? 0 : frame_parms->nb_prefix_samples);
+    nb_prefix_samples0 = (no_prefix ? 0 : frame_parms->nb_prefix_samples0);
+  }
+  else {
+    nb_prefix_samples = (no_prefix ? 0 : frame_parms->nb_prefix_samples);
+    nb_prefix_samples0 = (no_prefix ? 0 : frame_parms->nb_prefix_samples);
+  }
   //unsigned int subframe_offset;//,subframe_offset_F;
   unsigned int slot_offset;
   //int i;

openair1/PHY/NR_UE_ESTIMATION/nr_dl_channel_estimation.c

@@ -32,6 +32,7 @@
 //#define DEBUG_PDCCH
 
 
+
 int nr_pbch_channel_estimation(PHY_VARS_NR_UE *ue,
 			       uint8_t eNB_offset,
 			       unsigned char Ns,
@@ -47,13 +48,14 @@ int nr_pbch_channel_estimation(PHY_VARS_NR_UE *ue,
 
   //uint16_t Nid_cell = (eNB_offset == 0) ? ue->frame_parms.Nid_cell : ue->measurements.adj_cell_id[eNB_offset-1];
 
-  uint8_t nushift, ssb_index=0, n_hf=0;
+  uint8_t nushift;
+  uint8_t ssb_index=ue->i_ssb;
+  uint8_t n_hf=ue->n_hf;  
   int **dl_ch_estimates  =ue->common_vars.common_vars_rx_data_per_thread[ue->current_thread_id[Ns>>1]].dl_ch_estimates[eNB_offset];
   int **rxdataF=ue->common_vars.common_vars_rx_data_per_thread[ue->current_thread_id[Ns>>1]].rxdataF;
 
   nushift =  ue->frame_parms.Nid_cell%4;
   ue->frame_parms.nushift = nushift;
-
   unsigned int  ssb_offset = ue->frame_parms.first_carrier_offset + ue->frame_parms.ssb_start_subcarrier;
   if (ssb_offset>= ue->frame_parms.ofdm_symbol_size) ssb_offset-=ue->frame_parms.ofdm_symbol_size;
 
@@ -137,6 +139,7 @@ int nr_pbch_channel_estimation(PHY_VARS_NR_UE *ue,
     // Treat first 2 pilots specially (left edge)
     ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15);
     ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15);
+
 #ifdef DEBUG_CH
     printf("ch 0 %d\n",((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1]));
     printf("pilot 0 : rxF - > (%d,%d) addr %p  ch -> (%d,%d), pil -> (%d,%d) \n",rxF[0],rxF[1],&rxF[0],ch[0],ch[1],pil[0],pil[1]);
@@ -154,6 +157,8 @@ int nr_pbch_channel_estimation(PHY_VARS_NR_UE *ue,
 
     ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15);
     ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15);
+
+
 #ifdef DEBUG_CH
     printf("pilot 1 : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]);
 #endif
@@ -165,9 +170,6 @@ int nr_pbch_channel_estimation(PHY_VARS_NR_UE *ue,
     re_offset = (re_offset+4)&(ue->frame_parms.ofdm_symbol_size-1);
     rxF   = (int16_t *)&rxdataF[aarx][(symbol_offset+k+re_offset)];
 
-    ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15);
-    ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15);
-
 #ifdef DEBUG_CH
     printf("pilot 2 : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]);
 #endif
@@ -195,6 +197,7 @@ int nr_pbch_channel_estimation(PHY_VARS_NR_UE *ue,
       }
       ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15);
       ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15);
+
 #ifdef DEBUG_CH
       printf("pilot %d : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",pilot_cnt,rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]);
 #endif
@@ -213,6 +216,7 @@ int nr_pbch_channel_estimation(PHY_VARS_NR_UE *ue,
   
       ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15);
       ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15);
+
 #ifdef DEBUG_CH
       printf("pilot %d : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",pilot_cnt+1,rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]);
 #endif
@@ -247,7 +251,6 @@ int nr_pbch_channel_estimation(PHY_VARS_NR_UE *ue,
     //}
 
   }
-
   return(0);
 }
 

openair1/PHY/NR_UE_ESTIMATION/nr_estimation.h

@@ -64,6 +64,7 @@ int nr_pdsch_channel_estimation(PHY_VARS_NR_UE *ue,
 			      unsigned short bwp_start_subcarrier,
 			      unsigned short nb_rb_pdsch);
 
+							  
 void nr_adjust_synch_ue(NR_DL_FRAME_PARMS *frame_parms,
                       PHY_VARS_NR_UE *ue,
                       module_id_t eNB_id,

openair1/PHY/NR_UE_TRANSPORT/nr_initial_sync.c

@@ -53,38 +53,35 @@ int cnt=0;
 
 #define DEBUG_INITIAL_SYNCH
 
-int nr_pbch_detection(PHY_VARS_NR_UE *ue, runmode_t mode)
+
+int nr_pbch_detection(PHY_VARS_NR_UE *ue, int pbch_initial_symbol, runmode_t mode)
 {
   NR_DL_FRAME_PARMS *frame_parms=&ue->frame_parms;
   int ret =-1;
 
-
 #ifdef DEBUG_INITIAL_SYNCH
   LOG_I(PHY,"[UE%d] Initial sync: starting PBCH detection (rx_offset %d)\n",ue->Mod_id,
         ue->rx_offset);
 #endif
 
-  // save the nb_prefix_samples0 since we are not synchronized to subframes yet and the SSB has all symbols with nb_prefix_samples
-  int nb_prefix_samples0 = frame_parms->nb_prefix_samples0;
-  frame_parms->nb_prefix_samples0 = frame_parms->nb_prefix_samples;
-
+  uint8_t  N_L = (frame_parms->Lmax == 4)? 4:8;
+  uint8_t  N_hf = (frame_parms->Lmax == 4)? 2:1;
 
-  for(int i=1; i<4;i++) {
+  // loops over possible pbch dmrs cases to retrive best estimated i_ssb (and n_hf for Lmax=4) for multiple ssb detection
+  for (int hf = 0; hf < N_hf; hf++) {
+    for (int l = 0; l < N_L ; l++) {
+      if (ret !=0) {
+        ue->i_ssb = l;
+        ue->n_hf = hf;
 
 #if UE_TIMING_TRACE
         start_meas(&ue->dlsch_channel_estimation_stats);
 #endif
-    nr_pbch_channel_estimation(ue,0,
-			       0,
-			       i);
+        for(int i=pbch_initial_symbol; i<pbch_initial_symbol+3;i++)
+          nr_pbch_channel_estimation(ue,0,0,i);
 #if UE_TIMING_TRACE
         stop_meas(&ue->dlsch_channel_estimation_stats);
 #endif
-  }
-
-  //put back nb_prefix_samples0
-  frame_parms->nb_prefix_samples0 = nb_prefix_samples0;
-  
 
         ret = nr_rx_pbch(ue,
 	                 &ue->proc.proc_rxtx[0],
@@ -94,6 +91,9 @@ int nr_pbch_detection(PHY_VARS_NR_UE *ue, runmode_t mode)
                          SISO,
 		         ue->high_speed_flag);
 
+      }
+    }
+  }
 
   if (ret==0) {
     
@@ -211,6 +211,14 @@ int nr_initial_sync(PHY_VARS_NR_UE *ue, runmode_t mode)
   /* check that SSS/PBCH block is continuous inside the received buffer */
   if (sync_pos < (NR_NUMBER_OF_SUBFRAMES_PER_FRAME*fp->samples_per_subframe - (NB_SYMBOLS_PBCH * fp->ofdm_symbol_size))) {
 
+    /* slop_fep function works for lte and takes into account begining of frame with prefix for subframe 0 */
+    /* for NR this is not the case but slot_fep is still used for computing FFT of samples */
+    /* in order to achieve correct processing for NR prefix samples is forced to 0 and then restored after function call */
+    /* symbol number are from beginning of SS/PBCH blocks as below:  */
+    /*    Signal            PSS  PBCH  SSS  PBCH                     */
+    /*    symbol number      0     1    2    3                       */
+    /* time samples in buffer rxdata are used as input of FFT -> FFT results are stored in the frequency buffer rxdataF */
+    /* rxdataF stores SS/PBCH from beginning of buffers in the same symbol order as in time domain */
 
     for(int i=0; i<4;i++)
       nr_slot_fep(ue,
@@ -230,7 +238,7 @@ int nr_initial_sync(PHY_VARS_NR_UE *ue, runmode_t mode)
     //nr_init_frame_parms_ue(fp,NR_MU_1,NORMAL,n_ssb_crb,0);
 
     nr_gold_pbch(ue);
-    ret = nr_pbch_detection(ue,mode);
+    ret = nr_pbch_detection(ue,1,mode);  // start pbch detection at first symbol after pss
     
     nr_gold_pdcch(ue,0, 2);
     /*

openair1/PHY/NR_UE_TRANSPORT/nr_pbch.c

@@ -426,7 +426,7 @@ int nr_rx_pbch( PHY_VARS_NR_UE *ue,
   uint8_t nushift;
   uint16_t M;
   uint8_t Lmax=frame_parms->Lmax; 
-  uint8_t ssb_index=0;
+  uint8_t ssb_index=ue->i_ssb;
   //uint16_t crc;
   //unsigned short idx_demod =0;
   uint32_t decoderState=0;

openair1/PHY/NR_UE_TRANSPORT/nr_transport_proto_ue.h

@@ -1125,6 +1125,10 @@ int nr_rx_pbch( PHY_VARS_NR_UE *ue,
 		     MIMO_mode_t mimo_mode,
 		     uint32_t high_speed_flag);
 
+int nr_pbch_detection(PHY_VARS_NR_UE *ue,
+		      int pbch_initial_symbol,
+		      runmode_t mode);
+
 uint16_t rx_pbch_emul(PHY_VARS_NR_UE *phy_vars_ue,
                       uint8_t eNB_id,
                       uint8_t pbch_phase);

openair1/PHY/NR_UE_TRANSPORT/sss_nr.c

@@ -430,21 +430,6 @@ int rx_sss_nr(PHY_VARS_NR_UE *ue, int32_t *tot_metric,uint8_t *phase_max)
   int32_t metric, metric_re;
   int16_t *d;
 
-  /* slop_fep function works for lte and takes into account begining of frame with prefix for subframe 0 */
-  /* for NR this is not the case but slot_fep is still used for computing FFT of samples */
-  /* in order to achieve correct processing for NR prefix samples is forced to 0 and then restored after function call */
-  /* symbol number are from beginning of SS/PBCH blocks as below:  */
-  /*    Signal            PSS  PBCH  SSS  PBCH                     */
-  /*    symbol number      0     1    2    3                       */
-  /* time samples in buffer rxdata are used as input of FFT -> FFT results are stored in the frequency buffer rxdataF */
-  /* rxdataF stores SS/PBCH from beginning of buffers in the same symbol order as in time domain */
-
-  int nb_prefix_samples0 = frame_parms->nb_prefix_samples0;
-  // For now, symbol 0 = PSS/PBCH and it is never in symbol 0 or 7*2^mu (i.e. always shorter prefix)
-  frame_parms->nb_prefix_samples0 = frame_parms->nb_prefix_samples;
-
-
-  frame_parms->nb_prefix_samples0 = nb_prefix_samples0;
 
   // pss sss extraction
   pss_sss_extract_nr(ue,

openair1/PHY/defs_nr_UE.h

@@ -1143,6 +1143,8 @@ typedef struct {
   uint8_t               decode_MIB;
   /// temporary offset during cell search prior to MIB decoding
   int              ssb_offset;
+  uint8_t          i_ssb;
+  uint8_t          n_hf;
   int              rx_offset; /// Timing offset
   int              rx_offset_diff; /// Timing adjustment for ofdm symbol0 on HW USRP
   int              time_sync_cell;
@@ -1307,6 +1309,7 @@ typedef struct {
 
 } PHY_VARS_NR_UE;
 
+
 /* this structure is used to pass both UE phy vars and
  * proc to the function UE_thread_rxn_txnp4
  */

openair1/SCHED_NR_UE/phy_procedures_nr_ue.c

@@ -5098,7 +5098,7 @@ int phy_procedures_nrUE_RX(PHY_VARS_NR_UE *ue,UE_nr_rxtx_proc_t *proc,uint8_t eN
   if ( (nr_tti_rx == 0) && (ue->decode_MIB == 1))
     {
       LOG_D(PHY," ------  PBCH ChannelComp/LLR: frame.slot %d.%d ------  \n", frame_rx%1024, nr_tti_rx);
-      for (int i=0; i<3; i++)
+      for (int i=0; i<3; i++) {
 	nr_slot_fep(ue,
 		    (5+i), //mu=1 case B
 		    nr_tti_rx,
@@ -5106,6 +5106,15 @@ int phy_procedures_nrUE_RX(PHY_VARS_NR_UE *ue,UE_nr_rxtx_proc_t *proc,uint8_t eN
 		    0,
 		    NR_PBCH_EST);
 
+#if UE_TIMING_TRACE
+  	start_meas(&ue->dlsch_channel_estimation_stats);
+#endif
+   	nr_pbch_channel_estimation(ue,0,0,5+i);
+#if UE_TIMING_TRACE
+  	stop_meas(&ue->dlsch_channel_estimation_stats);
+#endif
+      
+      }
       nr_ue_pbch_procedures(eNB_id,ue,proc,0);
     }
   

openair1/SIMULATION/NR_PHY/pbchsim.c

@@ -372,7 +372,8 @@ int main(int argc, char **argv)
   frame_parms->N_RB_DL = N_RB_DL;
   frame_parms->N_RB_UL = N_RB_DL;
   frame_parms->Nid_cell = Nid_cell;
-  frame_parms->ssb_type = nr_ssb_type_B;
+  frame_parms->nushift = Nid_cell%4;
+  frame_parms->ssb_type = nr_ssb_type_C;
 
   nr_phy_config_request_sim(gNB,N_RB_DL,N_RB_DL,mu,Nid_cell,SSB_positions);
   phy_init_nr_gNB(gNB,0,0);
@@ -605,17 +606,9 @@ int main(int argc, char **argv)
 		      0,
 		      0,
 		      NR_PBCH_EST);
-
-          nr_pbch_channel_estimation(UE,0,0,i);
         }
 
-	ret = nr_rx_pbch(UE,
-			 &UE->proc.proc_rxtx[0],
-			 UE->pbch_vars[0],
-			 frame_parms,
-			 0,
-			 SISO,
-			 UE->high_speed_flag);
+	ret = nr_pbch_detection(UE,5,0); // start pbch detection from symbol 5 and mode 0
 
 	if (ret==0) {
 	  //UE->rx_ind.rx_indication_body->mib_pdu.ssb_index;  //not yet detected automatically