fixes for TDL channel models in nr_ulsim

openair1/SIMULATION/TOOLS/channel_sim.c

@@ -180,7 +180,7 @@ void do_DL_sig(sim_t *sim,
     
     //RU2UE[eNB_id][UE_id]->path_loss_dB = 0;
     multipath_channel(sim->RU2UE[ru_id][UE_id][CC_id],s_re,s_im,r_re0,r_im0,
-		      length,hold_channel);
+		      length,hold_channel,0);
 #ifdef DEBUG_SIM
     rx_pwr = signal_energy_fp2(sim->RU2UE[ru_id][UE_id][CC_id]->ch[0],
 			       sim->RU2UE[ru_id][UE_id][CC_id]->channel_length)*sim->RU2UE[ru_id][UE_id][CC_id]->channel_length;
@@ -394,7 +394,7 @@ void do_UL_sig(sim_t *sim,
       
       
       multipath_channel(sim->UE2RU[UE_id][ru_id][CC_id],s_re,s_im,r_re0,r_im0,
-			frame_parms->samples_per_tti,hold_channel);
+			frame_parms->samples_per_tti,hold_channel,0);
       
       
       rx_pwr = signal_energy_fp2(sim->UE2RU[UE_id][ru_id][CC_id]->ch[0],

openair1/SIMULATION/TOOLS/multipath_channel.c

@@ -44,7 +44,8 @@ void multipath_channel(channel_desc_t *desc,
                        double rx_sig_re[2][30720*2],
                        double rx_sig_im[2][30720*2],
                        uint32_t length,
-                       uint8_t keep_channel)
+                       uint8_t keep_channel,
+		       int log_channel)
 {
 
   int i,ii,j,l;
@@ -150,7 +151,8 @@ void multipath_channel(channel_desc_t *desc,
                        double *rx_sig_re[2],
                        double *rx_sig_im[2],
                        uint32_t length,
-                       uint8_t keep_channel)
+                       uint8_t keep_channel,
+		       int log_channel)
 {
 
   int i,ii,j,l;
@@ -196,6 +198,11 @@ void multipath_channel(channel_desc_t *desc,
 
           rx_tmp.x += (tx.x * desc->ch[ii+(j*desc->nb_rx)][l].x) - (tx.y * desc->ch[ii+(j*desc->nb_rx)][l].y);
           rx_tmp.y += (tx.y * desc->ch[ii+(j*desc->nb_rx)][l].x) + (tx.x * desc->ch[ii+(j*desc->nb_rx)][l].y);
+	  if (i==0 && log_channel == 1) {
+	    printf("channel[%d][%d][%d] = %f dB (%e,%e)\n",ii,j,l,10*log10(pow(desc->ch[ii+(j*desc->nb_rx)][l].x,2.0)+pow(desc->ch[ii+(j*desc->nb_rx)][l].y,2.0)),
+		   desc->ch[ii+(j*desc->nb_rx)][l].x,
+		   desc->ch[ii+(j*desc->nb_rx)][l].y);
+	  }
         } //l
       }  // j
 

openair1/SIMULATION/TOOLS/random_channel.c

@@ -695,9 +695,10 @@ channel_desc_t *new_channel_desc_scm(uint8_t nb_tx,
         sum_amps += chan_desc->amps[i];
       }
 
-      for (i = 0; i<chan_desc->nb_taps; i++)
+      for (i = 0; i<chan_desc->nb_taps; i++) {
         chan_desc->amps[i] /= sum_amps;
-
+	tdl_delays[i] *= DS_TDL;
+      }
       chan_desc->delays         = tdl_delays;
       chan_desc->ricean_factor  = tdl_ricean_factor;
       chan_desc->aoa            = 0;
@@ -1733,15 +1734,14 @@ int random_channel(channel_desc_t *desc, uint8_t abstraction_flag) {
 
               desc->ch[aarx+(aatx*desc->nb_rx)][k].x += s*desc->a[l][aarx+(aatx*desc->nb_rx)].x;
               desc->ch[aarx+(aatx*desc->nb_rx)][k].y += s*desc->a[l][aarx+(aatx*desc->nb_rx)].y;
-              //    printf("l %d : desc->ch.x %f\n",l,desc->a[l][aarx+(aatx*desc->nb_rx)].x);
+	      //	      printf("l %d : desc->ch.x %f, s %e, delay %f\n",l,desc->a[l][aarx+(aatx*desc->nb_rx)].x,s,desc->delays[l]);
             } //nb_taps
 
 #ifdef DEBUG_CH
-            k=0;
-            printf("(%d,%d,%d)->(%f,%f)\n",k,aarx,aatx,desc->ch[aarx+(aatx*desc->nb_rx)][k].x,desc->ch[aarx+(aatx*desc->nb_rx)][k].y);
+            printf("(%d,%d,%d)->(%e,%e)\n",k,aarx,aatx,desc->ch[aarx+(aatx*desc->nb_rx)][k].x,desc->ch[aarx+(aatx*desc->nb_rx)][k].y);
 #endif
-          }
-        } //channel_length
+          } //channel_length
+        } 
       } //aatx
     } //aarx
 

openair1/SIMULATION/TOOLS/sim.h

@@ -277,7 +277,8 @@ int random_channel(channel_desc_t *desc, uint8_t abstraction_flag);
            double rx_sig_re[2],
            double rx_sig_im[2],
            uint32_t length,
-           uint8_t keep_channel)
+           uint8_t keep_channel,
+	   int log_channel)
 
 \brief This function generates and applys a random frequency selective random channel model.
 @param desc Pointer to channel descriptor
@@ -287,6 +288,7 @@ int random_channel(channel_desc_t *desc, uint8_t abstraction_flag);
 @param rx_sig_im output signal (imaginary component)
 @param length Length of input signal
 @param keep_channel Set to 1 to keep channel constant for null-B/F
+@param log_channel=1 make channel coefficients come out for first sample of input
 */
 
 void multipath_channel(channel_desc_t *desc,
@@ -295,7 +297,8 @@ void multipath_channel(channel_desc_t *desc,
                        double *rx_sig_re[2],
                        double *rx_sig_im[2],
                        uint32_t length,
-                       uint8_t keep_channel);
+                       uint8_t keep_channel,
+		       int log_channel);
 /*
 \fn double compute_pbch_sinr(channel_desc_t *desc,
                              channel_desc_t *desc_i1,