Extend rfsim to enable muti transmit antennas for gNB+solve beamforming ssb_index 0 when nb_tx>1

openair1/PHY/INIT/nr_init_ru.c

@@ -121,9 +121,9 @@ int nr_phy_init_RU(RU_t *ru) {
     LOG_E(PHY,"[INIT] %s() RC.nb_nr_L1_inst:%d \n", __FUNCTION__, RC.nb_nr_L1_inst);
     
     int beam_count = 0;
-    if (ru->nb_log_antennas>1) {
+    if (ru->nb_tx>1) {//Enable beamforming when nb_tx > 1
       for (p=0;p<ru->nb_log_antennas;p++) {
-        if ((fp->L_ssb >> p) & 0x01)
+        if ((fp->L_ssb >> (63-p)) & 0x01)//64 bit-map with the MSB @2⁶³ corresponds to SSB ssb_index 0
           beam_count++;
       }
       AssertFatal(ru->nb_bfw==(beam_count*ru->nb_tx),"Number of beam weights from config file is %d while the expected number is %d",ru->nb_bfw,(beam_count*ru->nb_tx));
@@ -131,7 +131,7 @@ int nr_phy_init_RU(RU_t *ru) {
       int l_ind = 0;
       for (i=0; i<RC.nb_nr_L1_inst; i++) {
         for (p=0;p<ru->nb_log_antennas;p++) {
-          if ((fp->L_ssb >> p) & 0x01)  {
+          if ((fp->L_ssb >> (63-p)) & 0x01)  {
 	    ru->beam_weights[i][p] = (int32_t **)malloc16_clear(ru->nb_tx*sizeof(int32_t*));
 	    for (j=0; j<ru->nb_tx; j++) {
 	      ru->beam_weights[i][p][j] = (int32_t *)malloc16_clear(fp->ofdm_symbol_size*sizeof(int32_t));

openair1/PHY/INIT/nr_parms.c

@@ -308,7 +308,7 @@ int nr_init_frame_parms(nfapi_nr_config_request_scf_t* cfg,
   int num_tx_ant = (cfg == NULL) ? fp->Lmax : cfg->carrier_config.num_tx_ant.value;
 
   for (int p=0; p<num_tx_ant; p++)
-    fp->N_ssb += ((fp->L_ssb >> p) & 0x01);
+    fp->N_ssb += ((fp->L_ssb >> (63-p)) & 0x01);
 
   return 0;
 
@@ -389,7 +389,7 @@ int nr_init_frame_parms_ue(NR_DL_FRAME_PARMS *fp,
   
   fp->N_ssb = 0;
   for (int p=0; p<fp->Lmax; p++)
-    fp->N_ssb += ((fp->L_ssb >> p) & 0x01);
+    fp->N_ssb += ((fp->L_ssb >> (63-p)) & 0x01);
 
   return 0;
 }

openair1/PHY/MODULATION/beamforming.c

@@ -155,7 +155,7 @@ int nr_beam_precoding(int32_t **txdataF,
   memset(&txdataF_BF[aa][symbol*frame_parms->ofdm_symbol_size],0,sizeof(int32_t)*(frame_parms->ofdm_symbol_size));
 
   for (p=0; p<nb_antenna_ports; p++) {
-    if ((frame_parms->L_ssb >> p) & 0x01)  {
+    if ((frame_parms->L_ssb >> (63-p)) & 0x01)  {
       multadd_cpx_vector((int16_t*)&txdataF[p][symbol*frame_parms->ofdm_symbol_size],
 			 (int16_t*)beam_weights[p][aa], 
 			 (int16_t*)&txdataF_BF[aa][symbol*frame_parms->ofdm_symbol_size], 

targets/ARCH/rfsimulator/simulator.c

@@ -510,7 +510,7 @@ static bool flushInput(rfsimulator_state_t *t, int timeout, int nsamps_for_initi
           LOG_E(HW,"UEsock: %d Tx/Rx shift too large Tx:%lu, Rx:%lu\n", fd, t->lastWroteTS, b->lastReceivedTS);
 
         pthread_mutex_unlock(&Sockmutex);
-        b->transferPtr=(char *)&b->circularBuf[b->lastReceivedTS%CirSize];
+        b->transferPtr=(char *)&b->circularBuf[(b->lastReceivedTS*b->th.nbAnt)%CirSize];
         b->remainToTransfer=sampleToByte(b->th.size, b->th.nbAnt);
       }
 
@@ -641,7 +641,7 @@ int rfsimulator_read(openair0_device *device, openair0_timestamp *ptimestamp, vo
       if (reGenerateChannel)
         random_channel(ptr->channel_model,0);
 
-      for (int a=0; a<nbAnt; a++) {
+      for (int a=0; a<nbAnt; a++) {//loop over number of Rx antennas
         if ( ptr->channel_model != NULL ) // apply a channel model
           rxAddInput( ptr->circularBuf, (struct complex16 *) samplesVoid[a],
                       a,
@@ -652,14 +652,16 @@ int rfsimulator_read(openair0_device *device, openair0_timestamp *ptimestamp, vo
                     );
         else { // no channel modeling
           sample_t *out=(sample_t *)samplesVoid[a];
-          const int64_t base=t->nextTimestamp*nbAnt+a;
-          for ( int i=0; i < nsamps; i++ ) {
-	    const int idx=(i*nbAnt+base)%CirSize;
-            out[i].r+=ptr->circularBuf[idx].r;
-            out[i].i+=ptr->circularBuf[idx].i;
-          }
+          int nbAnt_tx = ptr->th.nbAnt;//number of Tx antennas
+          //LOG_I(HW, "nbAnt_tx %d\n",nbAnt_tx);
+          for (int i=0; i < nsamps; i++) {//loop over nsamps
+        	  for (int a_tx=0; a_tx<nbAnt_tx; a_tx++){//sum up signals from nbAnt_tx antennas
+        		  out[i].r+=ptr->circularBuf[((t->nextTimestamp+i)*nbAnt_tx+a_tx)%CirSize].r;
+        		  out[i].i+=ptr->circularBuf[((t->nextTimestamp+i)*nbAnt_tx+a_tx)%CirSize].i;
+        	  } // end for a_tx
+          } // end for i (number of samps)
         } // end of no channel modeling
-      } // end for a...
+      } // end for a (number of rx antennas)
     }
   }
 

targets/PROJECTS/GENERIC-LTE-EPC/CONF/gnb.band78.tm1.106PRB.usrpn300.conf

@@ -248,6 +248,8 @@ RUs = (
          max_pdschReferenceSignalPower = -27;
          max_rxgain                    = 114;
          eNB_instances  = [0];
+         #beamforming 1x4 matrix:
+         bf_weights = [0x00007fff, 0x0000, 0x0000, 0x0000];
          sdr_addrs = "addr=192.168.10.2,mgmt_addr=192.168.10.2,second_addr=192.168.20.2";
          clock_src = "external";
     }