adding functions to compute bf weights to dlsim

openair1/PHY/LTE_TRANSPORT/defs.h

@@ -242,6 +242,8 @@ typedef struct {
   int32_t *txdataF[8];
   /// beamforming weights for UE-spec transmission (antenna ports 5 or 7..14), for each codeword, maximum 4 layers?
   int32_t **ue_spec_bf_weights[4]; 
+  /// dl channel estimates (estimated from ul channel estimates)
+  int32_t **calib_dl_ch_estimates;
   /// Allocated RNTI (0 means DLSCH_t is not currently used)
   uint16_t rnti;
   /// Active flag for baseband transmitter processing

openair1/PHY/MODULATION/compute_bf_weights.c

@@ -47,8 +47,10 @@ int compute_BF_weights(int32_t **beam_weights, int32_t **calib_dl_ch_estimates,
 } 
 
 // temporal test function
+/*
 void main(){
   // initialization
   // compare
   printf("Hello world!\n");
-}
+}
+*/

openair1/PHY/impl_defs_lte.h

@@ -641,18 +641,16 @@ typedef struct {
   /// - first index: eNB id [0..2] (hard coded)
   /// - second index: sample [0..samples_per_tti*10[
   uint32_t *sync_corr[3];
-  // int32_t **beam_weights[3][15];
   /// \brief Holds the beamforming weights
   /// - first index: eNB id [0..2] (hard coded)
-  /// - second index: eNB antenna port index
+  /// - second index: eNB antenna port index (hard coded)
   /// - third index: tx antenna [0..nb_antennas_tx[
   /// - fourth index: sample [0..]
   int32_t **beam_weights[3][15];
   /// \brief Holds the tdd reciprocity calibration coefficients 
   /// - first index: eNB id [0..2] (hard coded) 
-  /// - second index: ue specific eNB antenna port index, port5->index0, port7-15->index0-7
+  /// - second index: tx antenna [0..nb_antennas_tx[
-  /// - third index: tx antenna [0..nb_antennas_tx[
+  /// - third index: frequency [0..]
-  /// - forth index: frenquency [0..]
   int32_t **tdd_calib_coeffs[3];
 } LTE_eNB_COMMON;
 

openair1/SIMULATION/LTE_PHY/dlsim.c

@@ -991,6 +991,9 @@ int main(int argc, char **argv)
       PHY_vars_eNB->eNB_UE_stats[1].DL_pmi_single = 0;
   }
 
+  //TODO: allocate memory for calibration matrix and calib_dl_ch_estimates in init_lte.c
+  //for first tests initialze calibration matrix with idendity
+  //read_calibration_matrix(calib_fname, nb_ant, nb_freq, PHY_vars_eNB->lte_eNB_common_vars.tdd_calib_coeffs[0]);
 
   if (input_fd==NULL) {
 
@@ -2142,6 +2145,32 @@ int main(int argc, char **argv)
 
 PMI_FEEDBACK:
 
+	  //make sure dlsim is called with perfect channel estimation option (for freq_channel)
+	  //fill drs_ch_estimates with data from eNB2UE->chF
+	  for(aa=0; aa<frame_parms->nb_antenna_ports_eNB; aa++) {
+	    for (aarx=0; aarx<frame_parms->nb_antennas_rx; aarx++) {
+	      for (i=0; i<frame_parms->N_RB_DL*12; i++) {
+		for (l=0; l<frame_parms->symbols_per_tti; l++) {
+		  ((int16_t *) PHY_vars_eNB->lte_eNB_pusch_vars[0]->drs_ch_estimates[0][(aa<<1)+aarx])[2*i+(l*frame_parms->ofdm_symbol_size)*2]=(int16_t)(eNB2UE[round]->chF[aarx+(aa*frame_parms->nb_antennas_rx)][i].x*AMP);
+                          //printf("x=%d,AMP=%d\n",eNB2UE[round]->chF[aarx+(aa*frame_parms->nb_antennas_rx)][i].x,AMP);
+		  ((int16_t *) PHY_vars_eNB->lte_eNB_pusch_vars[0]->drs_ch_estimates[0][(aa<<1)+aarx])[2*i+1+(l*frame_parms->ofdm_symbol_size)*2]=(int16_t)(eNB2UE[round]->chF[aarx+(aa*frame_parms->nb_antennas_rx)][i].y*AMP);
+		}
+	      }
+	    }
+	  }
+
+	  estimate_DLCSI_from_ULCSI(PHY_vars_eNB->dlsch_eNB[0][0]->calib_dl_ch_estimates,
+					 &PHY_vars_eNB->lte_eNB_pusch_vars[0]->drs_ch_estimates[0][0/*position of second DMRS*/],
+					 PHY_vars_eNB->lte_eNB_common_vars.tdd_calib_coeffs[0],
+					 frame_parms->nb_antennas_tx,
+					 frame_parms->N_RB_DL*12);
+	  
+	  compute_BF_weights(PHY_vars_eNB->dlsch_eNB[0][0]->ue_spec_bf_weights[0],
+			     PHY_vars_eNB->dlsch_eNB[0][0]->calib_dl_ch_estimates,
+			     MRT,
+			     frame_parms->nb_antennas_tx,
+			     frame_parms->N_RB_DL*12);
+
           //printf("Trial %d : Round %d, pmi_feedback %d \n",trials,round,pmi_feedback);
           for (aa=0; aa<NB_ANTENNA_PORTS_ENB; aa++) {
             memset(&PHY_vars_eNB->lte_eNB_common_vars.txdataF[eNB_id][aa][0],0,FRAME_LENGTH_COMPLEX_SAMPLES_NO_PREFIX*sizeof(int32_t));
@@ -3088,6 +3117,7 @@ PMI_FEEDBACK:
                                 eNB2UE[round]->chF[aarx+(aa*frame_parms->nb_antennas_rx)][i].y*AMP);
 
                           if (transmission_mode == 7){
+			    //this should include the BF weights! Will not work for a random channel
                             if (PHY_vars_UE->high_speed_flag==0) {
                               ((int16_t *)PHY_vars_UE->lte_ue_pdsch_vars[0]->dl_bf_ch_estimates[(aa<<1)+aarx])[2*i]=(int16_t)(
                                   eNB2UE[round]->chF[aarx+(aa*frame_parms->nb_antennas_rx)][i].x*AMP);