Merge branch 'hotfix-71-freq_channel' into 'develop'

Hotfix 71 freq channel

only affects dlsim, which has been tested by Elena

See merge request !12

cmake_targets/lte-simulators/CMakeLists.txt

@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 2.8)
 set(PACKAGE_NAME "unitary_tests_simulators")
 set(PHYSIM True)
 set(RF_BOARD None)
-set(XFORMS False)
+set(XFORMS True)
 
 set(DEBUG_PHY False)
 set(MU_RECIEVER False)

openair1/SIMULATION/LTE_PHY/dlsim.c

@@ -2791,8 +2791,16 @@ PMI_FEEDBACK:
                 random_channel(eNB2UE[2],0);
                 random_channel(eNB2UE[3],0);
               }
-          }
-
+	    
+	    if (PHY_vars_UE->perfect_ce==1) {
+                  // fill in perfect channel estimates
+                  freq_channel(eNB2UE[round],PHY_vars_UE->lte_frame_parms.N_RB_DL,12*PHY_vars_UE->lte_frame_parms.N_RB_DL + 1);
+		  /*
+		  write_output("channel.m","ch",eNB2UE[round]->ch[0],eNB2UE[round]->channel_length,1,8);
+                  write_output("channelF.m","chF",eNB2UE[round]->chF[0],12*PHY_vars_UE->lte_frame_parms.N_RB_DL + 1,1,8);
+		  */
+	    }
+	  }
 
           if(abstx) {
             if (trials==0 && round==0) {
@@ -2938,11 +2946,6 @@ PMI_FEEDBACK:
 
               if (PHY_vars_UE->perfect_ce==1) {
                 if (awgn_flag==0) {
-                  // fill in perfect channel estimates
-                  freq_channel(eNB2UE[round],PHY_vars_UE->lte_frame_parms.N_RB_DL,12*PHY_vars_UE->lte_frame_parms.N_RB_DL + 1);
-
-                  //write_output("channel.m","ch",desc1->ch[0],desc1->channel_length,1,8);
-                  //write_output("channelF.m","chF",desc1->chF[0],nb_samples,1,8);
                   for(k=0; k<NUMBER_OF_eNB_MAX; k++) {
                     for(aa=0; aa<frame_parms->nb_antennas_tx; aa++) {
                       for (aarx=0; aarx<frame_parms->nb_antennas_rx; aarx++) {

openair1/SIMULATION/TOOLS/abstraction.c

@@ -45,7 +45,7 @@ double **cos_lut=NULL,**sin_lut=NULL;
 
 
 
-void init_freq_channel(channel_desc_t *desc,uint16_t nb_rb,int16_t n_samples)
+int init_freq_channel(channel_desc_t *desc,uint16_t nb_rb,int16_t n_samples)
 {
 
 
@@ -54,15 +54,17 @@ void init_freq_channel(channel_desc_t *desc,uint16_t nb_rb,int16_t n_samples)
   int16_t f;
   uint8_t l;
 
+  if ((n_samples&1)==0) {
+    fprintf(stderr, "freq_channel_init: n_samples has to be odd\n");
+    return(-1); 
+  }
 
   cos_lut = (double **)malloc(n_samples*sizeof(double*));
   sin_lut = (double **)malloc(n_samples*sizeof(double*));
 
-
-
   delta_f = nb_rb*180000/(n_samples-1);
 
-  for (f=-(n_samples>>1); f<(n_samples>>1); f++) {
+  for (f=-(n_samples>>1); f<=(n_samples>>1); f++) {
     freq=delta_f*(double)f*1e-6;// due to the fact that delays is in mus
 
     cos_lut[f+(n_samples>>1)] = (double *)malloc((int)desc->nb_taps*sizeof(double));
@@ -81,9 +83,11 @@ void init_freq_channel(channel_desc_t *desc,uint16_t nb_rb,int16_t n_samples)
 
     }
   }
+
+  return(0);
 }
 
-void freq_channel(channel_desc_t *desc,uint16_t nb_rb,int16_t n_samples)
+int freq_channel(channel_desc_t *desc,uint16_t nb_rb,int16_t n_samples)
 {
 
 
@@ -93,22 +97,32 @@ void freq_channel(channel_desc_t *desc,uint16_t nb_rb,int16_t n_samples)
   static int freq_channel_init=0;
   static int n_samples_max=0;
 
-  // printf("no of samples:%d,",n_samples);
+  // do some error checking
+  // n_samples has to be a odd number because we assume the spectrum is symmetric around the DC and includes the DC
+  if ((n_samples&1)==0) {
+    fprintf(stderr, "freq_channel: n_samples has to be odd\n");
+    return(-1); 
+  }
+
   // printf("no of taps:%d,",(int)desc->nb_taps);
 
   if (freq_channel_init == 0) {
     // we are initializing the lut for the largets possible n_samples=12*nb_rb+1
     // if called with n_samples<12*nb_rb+1, we decimate the lut
     n_samples_max=12*nb_rb+1;
-    init_freq_channel(desc,nb_rb,n_samples_max);
-    freq_channel_init=1;
+    if (init_freq_channel(desc,nb_rb,n_samples_max)==0)
+      freq_channel_init=1;
+    else
+      return(-1);
   }
 
-  d=n_samples_max/n_samples;
+  d=(n_samples_max-1)/(n_samples-1);
+
+  //printf("no_samples=%d, n_samples_max=%d, d=%d\n",n_samples,n_samples_max,d);
 
   start_meas(&desc->interp_freq);
 
-  for (f=-n_samples_max/2,f2=-n_samples/2; f<n_samples_max/2; f+=d,f2++) {
+  for (f=-n_samples_max/2,f2=-n_samples/2; f<=n_samples_max/2; f+=d,f2++) {
     clut = cos_lut[n_samples_max/2+f];
     slut = sin_lut[n_samples_max/2+f];
 
@@ -129,6 +143,8 @@ void freq_channel(channel_desc_t *desc,uint16_t nb_rb,int16_t n_samples)
   }
 
   stop_meas(&desc->interp_freq);
+
+  return(0);
 }
 
 double compute_pbch_sinr(channel_desc_t *desc,

openair1/SIMULATION/TOOLS/defs.h

@@ -354,8 +354,8 @@ int gauss(unsigned int *gauss_LUT,unsigned char Nbits);
 double gaussdouble(double,double);
 void randominit(unsigned int seed_init);
 double uniformrandom(void);
-void freq_channel(channel_desc_t *desc,uint16_t nb_rb, int16_t n_samples);
-void init_freq_channel(channel_desc_t *desc,uint16_t nb_rb,int16_t n_samples);
+int freq_channel(channel_desc_t *desc,uint16_t nb_rb, int16_t n_samples);
+int init_freq_channel(channel_desc_t *desc,uint16_t nb_rb,int16_t n_samples);
 uint8_t multipath_channel_nosigconv(channel_desc_t *desc);
 void multipath_tv_channel(channel_desc_t *desc,
                           double **tx_sig_re,