slot_fep.c 6.54 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85
#include "PHY/defs.h"
#include "MAC_INTERFACE/extern.h"
#include "defs.h"
//#define DEBUG_FEP

#define SOFFSET 0

int slot_fep(PHY_VARS_UE *phy_vars_ue,
	     unsigned char l,
	     unsigned char Ns,
	     int sample_offset,
	     int no_prefix) {

  LTE_DL_FRAME_PARMS *frame_parms = &phy_vars_ue->lte_frame_parms;
  LTE_UE_COMMON *ue_common_vars   = &phy_vars_ue->lte_ue_common_vars;
  u8 eNB_id = 0;//ue_common_vars->eNb_id;
  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 subframe_offset;//,subframe_offset_F;
  unsigned int slot_offset;
  int i;
  unsigned int frame_length_samples = frame_parms->samples_per_tti * 10;
  unsigned int rx_offset;

  void (*dft)(int16_t *,int16_t *, int);

  switch (frame_parms->log2_symbol_size) {
  case 7:
    dft = dft128;
    break;
  case 8:
    dft = dft256;
    break;
  case 9:
    dft = dft512;
    break;
  case 10:
    dft = dft1024;
    break;
  case 11:
    dft = dft2048;
    break;
  default:
    dft = dft512;
    break;
  }

  if (no_prefix) {
    subframe_offset = frame_parms->ofdm_symbol_size * frame_parms->symbols_per_tti * (Ns>>1);
    slot_offset = frame_parms->ofdm_symbol_size * (frame_parms->symbols_per_tti>>1) * (Ns%2);
  }
  else {
    subframe_offset = frame_parms->samples_per_tti * (Ns>>1);
    slot_offset = (frame_parms->samples_per_tti>>1) * (Ns%2);
  }
  //  subframe_offset_F = frame_parms->ofdm_symbol_size * frame_parms->symbols_per_tti * (Ns>>1);


  if (l<0 || l>=7-frame_parms->Ncp) {
    msg("slot_fep: l must be between 0 and %d\n",7-frame_parms->Ncp);
    return(-1);
  }
  if (Ns<0 || Ns>=20) {
    msg("slot_fep: Ns must be between 0 and 19\n");
    return(-1);
  }

#ifdef DEBUG_FEP
  //  if (phy_vars_ue->frame <100)
    msg("slot_fep: frame %d: slot %d, symbol %d, nb_prefix_samples %d, nb_prefix_samples0 %d, slot_offset %d, subframe_offset %d, sample_offset %d\n", phy_vars_ue->frame,Ns, symbol, nb_prefix_samples,nb_prefix_samples0,slot_offset,subframe_offset,sample_offset);
#endif
  

  for (aa=0;aa<frame_parms->nb_antennas_rx;aa++) {
#ifdef NEW_FFT
    memset(&ue_common_vars->rxdataF[aa][frame_parms->ofdm_symbol_size*symbol],0,frame_parms->ofdm_symbol_size*sizeof(int));
#else
    memset(&ue_common_vars->rxdataF[aa][2*frame_parms->ofdm_symbol_size*symbol],0,2*frame_parms->ofdm_symbol_size*sizeof(int));
#endif

    if (l==0) {
      rx_offset = sample_offset + slot_offset + nb_prefix_samples0 + subframe_offset - SOFFSET;
      // Align with 128 bit
86
      rx_offset = rx_offset - rx_offset % 4;
87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115
      if (rx_offset > (frame_length_samples - frame_parms->ofdm_symbol_size))
	memcpy((short *)&ue_common_vars->rxdata[aa][frame_length_samples],
	       (short *)&ue_common_vars->rxdata[aa][0],
	       frame_parms->ofdm_symbol_size*sizeof(int));
#ifndef NEW_FFT
	fft((short *)&ue_common_vars->rxdata[aa][(sample_offset +
						slot_offset +
						nb_prefix_samples0 + 
						subframe_offset -
						SOFFSET) % frame_length_samples],
	  (short*)&ue_common_vars->rxdataF[aa][2*frame_parms->ofdm_symbol_size*symbol],
	  frame_parms->twiddle_fft,
	  frame_parms->rev,
	  frame_parms->log2_symbol_size,
	  frame_parms->log2_symbol_size>>1,
	  0);
#else
	start_meas(&phy_vars_ue->rx_dft_stats);
	dft((int16_t *)&ue_common_vars->rxdata[aa][(rx_offset) % frame_length_samples],
	    (int16_t *)&ue_common_vars->rxdataF[aa][frame_parms->ofdm_symbol_size*symbol],1);
	stop_meas(&phy_vars_ue->rx_dft_stats);
#endif
      
    }
    else {
      rx_offset = sample_offset + slot_offset + 
        (frame_parms->ofdm_symbol_size+nb_prefix_samples0+nb_prefix_samples) +
        (frame_parms->ofdm_symbol_size+nb_prefix_samples)*(l-1) + subframe_offset - SOFFSET;
      
116
      rx_offset = rx_offset - (rx_offset % 4);
117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201

      if (rx_offset > (frame_length_samples - frame_parms->ofdm_symbol_size))
	memcpy((short *)&ue_common_vars->rxdata[aa][frame_length_samples],
	       (short *)&ue_common_vars->rxdata[aa][0],
	       frame_parms->ofdm_symbol_size*sizeof(int));
 
#ifndef NEW_FFT
      fft((short *)&ue_common_vars->rxdata[aa][(sample_offset +
						slot_offset +
						(frame_parms->ofdm_symbol_size+nb_prefix_samples0+nb_prefix_samples) + 
						(frame_parms->ofdm_symbol_size+nb_prefix_samples)*(l-1) +
						subframe_offset-
						SOFFSET) % frame_length_samples],
	  (short*)&ue_common_vars->rxdataF[aa][2*frame_parms->ofdm_symbol_size*symbol],
	  frame_parms->twiddle_fft,
	  frame_parms->rev,
	  frame_parms->log2_symbol_size,
	  frame_parms->log2_symbol_size>>1,
	  0);
#else
	start_meas(&phy_vars_ue->rx_dft_stats);
	dft((int16_t *)&ue_common_vars->rxdata[aa][(rx_offset) % frame_length_samples],
	    (int16_t *)&ue_common_vars->rxdataF[aa][frame_parms->ofdm_symbol_size*symbol],1);
	stop_meas(&phy_vars_ue->rx_dft_stats);
#endif
    }
    /*
#ifndef NEW_FFT
    memcpy(&ue_common_vars->rxdataF2[aa][2*subframe_offset_F+2*frame_parms->ofdm_symbol_size*symbol],
	   &ue_common_vars->rxdataF[aa][2*frame_parms->ofdm_symbol_size*symbol],
	   2*frame_parms->ofdm_symbol_size*sizeof(int));
    
#else
    memcpy(&ue_common_vars->rxdataF2[aa][subframe_offset_F+frame_parms->ofdm_symbol_size*symbol],
	   &ue_common_vars->rxdataF[aa][frame_parms->ofdm_symbol_size*symbol],
	   frame_parms->ofdm_symbol_size*sizeof(int));
#endif
    */
  }
#ifndef PERFECT_CE    
  if ((l==0) || (l==(4-frame_parms->Ncp))) {
    for (aa=0;aa<frame_parms->nb_antennas_tx_eNB;aa++) {

#ifdef DEBUG_FEP
      msg("Channel estimation eNB %d, aatx %d, slot %d, symbol %d\n",eNB_id,aa,Ns,l);
#endif
      start_meas(&phy_vars_ue->dlsch_channel_estimation_stats);
      lte_dl_channel_estimation(phy_vars_ue,eNB_id,0,
				Ns,
				aa,
				l,
				symbol);
      stop_meas(&phy_vars_ue->dlsch_channel_estimation_stats);

      for (i=0;i<phy_vars_ue->PHY_measurements.n_adj_cells;i++) {
	lte_dl_channel_estimation(phy_vars_ue,eNB_id,i+1,
				  Ns,
				  aa,
				  l,
				  symbol);
      }
    }


      // do frequency offset estimation here!
      // use channel estimates from current symbol (=ch_t) and last symbol (ch_{t-1}) 
#ifdef DEBUG_FEP
      msg("Frequency offset estimation\n");
#endif   
      if ((l == 0) || (l==(4-frame_parms->Ncp))) {
	start_meas(&phy_vars_ue->dlsch_freq_offset_estimation_stats);
	lte_est_freq_offset(ue_common_vars->dl_ch_estimates[0],
			    frame_parms,
			    l,
			    &ue_common_vars->freq_offset);
	stop_meas(&phy_vars_ue->dlsch_freq_offset_estimation_stats);

      }
  }
#endif
#ifdef DEBUG_FEP
  msg("slot_fep: done\n");
#endif
  return(0);
}