dlsch_demodulation.c

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/*! \file PHY/LTE_TRANSPORT/dlsch_demodulation.c
 * \brief Top-level routines for demodulating the PDSCH physical channel from 36-211, V8.6 2009-03
 * \author R. Knopp, F. Kaltenberger,A. Bhamri, S. Aubert
 * \date 2011
 * \version 0.1
 * \company Eurecom
 * \email: knopp@eurecom.fr,florian.kaltenberger@eurecom.fr,ankit.bhamri@eurecom.fr,sebastien.aubert@eurecom.fr
 * \note
 * \warning
 */
//#include "PHY/defs.h"
#include "PHY/extern.h"
#include "defs.h"
#include "extern.h"
#include "PHY/sse_intrin.h"


#ifndef USER_MODE
#define NOCYGWIN_STATIC static
#else
#define NOCYGWIN_STATIC
#endif

//#define DEBUG_HARQ

//#undef LOG_D
//#define LOG_D LOG_I

//#define DEBUG_PHY 1
//#define DEBUG_DLSCH_DEMOD 1

int avg[4];
int avg_0[2];
int avg_1[2];

// [MCS][i_mod (0,1,2) = (2,4,6)]
unsigned char offset_mumimo_llr_drange_fix=0;
uint8_t interf_unaw_shift0=0;
uint8_t interf_unaw_shift1=0;
uint8_t interf_unaw_shift=0;
//inferference-free case
unsigned char interf_unaw_shift_tm4_mcs[29]={5, 3, 4, 3, 3, 2, 1, 1, 2, 0, 1, 1, 1, 1, 0, 0,
                                             1, 1, 1, 1, 0, 2, 1, 0, 1, 0, 1, 0, 0} ;
unsigned char interf_unaw_shift_tm1_mcs[29]={5, 5, 4, 3, 3, 3, 2, 2, 4, 4, 2, 3, 3, 3, 1, 1,
                                             0, 1, 1, 2, 5, 4, 4, 6, 5, 1, 0, 5, 6} ; // mcs 21, 26, 28 seem to be errorneous

/*
//original values from sebastion + same hand tuning
unsigned char offset_mumimo_llr_drange[29][3]={{8,8,8},{7,7,7},{7,7,7},{7,7,7},{6,6,6},{6,6,6},{6,6,6},{5,5,5},{4,4,4},{1,2,4}, // QPSK
{5,5,4},{5,5,5},{5,5,5},{3,3,3},{2,2,2},{2,2,2},{2,2,2}, // 16-QAM
{2,2,1},{3,3,3},{3,3,3},{3,3,1},{2,2,2},{2,2,2},{0,0,0},{0,0,0},{0,0,0},{0,0,0},{0,0,0},{0,0,0}}; //64-QAM
*/
 /*
 //first optimization try
 unsigned char offset_mumimo_llr_drange[29][3]={{7, 8, 7},{6, 6, 7},{6, 6, 7},{6, 6, 6},{5, 6, 6},{5, 5, 6},{5, 5, 6},{4, 5, 4},{4, 3, 4},{3, 2, 2},{6, 5, 5},{5, 4, 4},{5, 5, 4},{3, 3, 2},{2, 2, 1},{2, 1, 1},{2, 2, 2},{3, 3, 3},{3, 3, 2},{3, 3, 2},{3, 2, 1},{2, 2, 2},{2, 2, 2},{0, 0, 0},{0, 0, 0},{0, 0, 0},{0, 0, 0},{0, 0, 0}};
 */
 //second optimization try
 /*
   unsigned char offset_mumimo_llr_drange[29][3]={{5, 8, 7},{4, 6, 8},{3, 6, 7},{7, 7, 6},{4, 7, 8},{4, 7, 4},{6, 6, 6},{3, 6, 6},{3, 6, 6},{1, 3, 4},{1, 1, 0},{3, 3, 2},{3, 4, 1},{4, 0, 1},{4, 2, 2},{3, 1, 2},{2, 1, 0},{2, 1, 1},{1, 0, 1},{1, 0, 1},{0, 0, 0},{1, 0, 0},{0, 0, 0},{0, 1, 0},{1, 0, 0},{0, 0, 0},{0, 0, 0},{0, 0, 0},{0, 0, 0}};  w
 */
unsigned char offset_mumimo_llr_drange[29][3]= {{0, 6, 5},{0, 4, 5},{0, 4, 5},{0, 5, 4},{0, 5, 6},{0, 5, 3},{0, 4, 4},{0, 4, 4},{0, 3, 3},{0, 1, 2},{1, 1, 0},{1, 3, 2},{3, 4, 1},{2, 0, 0},{2, 2, 2},{1, 1, 1},{2, 1, 0},{2, 1, 1},{1, 0, 1},{1, 0, 1},{0, 0, 0},{1, 0, 0},{0, 0, 0},{0, 1, 0},{1, 0, 0},{0, 0, 0},{0, 0, 0},{0, 0, 0},{0, 0, 0}};


extern void print_shorts(char *s,int16_t *x);


int rx_pdsch(PHY_VARS_UE *phy_vars_ue,
             PDSCH_t type,
             unsigned char eNB_id,
             unsigned char eNB_id_i, //if this == phy_vars_ue->n_connected_eNB, we assume MU interference
             uint8_t subframe,
             unsigned char symbol,
             unsigned char first_symbol_flag,
             RX_type_t rx_type,
             unsigned char i_mod,
             unsigned char harq_pid)
{

  LTE_UE_COMMON *lte_ue_common_vars  = &phy_vars_ue->lte_ue_common_vars;
  LTE_UE_PDSCH **lte_ue_pdsch_vars;
  LTE_DL_FRAME_PARMS *frame_parms    = &phy_vars_ue->lte_frame_parms;
  PHY_MEASUREMENTS *phy_measurements = &phy_vars_ue->PHY_measurements;
  LTE_UE_DLSCH_t   **dlsch_ue;


  unsigned char aatx,aarx;
  unsigned short nb_rb, round;
  int avgs, rb;

 LTE_DL_UE_HARQ_t *dlsch0_harq,*dlsch1_harq = 0;
  uint32_t *rballoc;

  int32_t **rxdataF_comp_ptr;
  int32_t **dl_ch_mag_ptr;
  int32_t codeword_TB0;
  int32_t codeword_TB1;



  switch (type) {
  case SI_PDSCH:
    lte_ue_pdsch_vars = &phy_vars_ue->lte_ue_pdsch_vars_SI[eNB_id];
    dlsch_ue          = &phy_vars_ue->dlsch_ue_SI[eNB_id];
    dlsch0_harq       = dlsch_ue[0]->harq_processes[harq_pid];
    break;

  case RA_PDSCH:
    lte_ue_pdsch_vars = &phy_vars_ue->lte_ue_pdsch_vars_ra[eNB_id];
    dlsch_ue          = &phy_vars_ue->dlsch_ue_ra[eNB_id];
    dlsch0_harq       = dlsch_ue[0]->harq_processes[harq_pid];
    break;

  case PDSCH:

    lte_ue_pdsch_vars = &phy_vars_ue->lte_ue_pdsch_vars[eNB_id];
    dlsch_ue          = phy_vars_ue->dlsch_ue[eNB_id];
    if ((dlsch_ue[0]->harq_processes[harq_pid]->status == ACTIVE) &&
        (dlsch_ue[1]->harq_processes[harq_pid]->status == ACTIVE)){
      codeword_TB0      = dlsch_ue[0]->harq_processes[harq_pid]->codeword;
      codeword_TB1      = dlsch_ue[1]->harq_processes[harq_pid]->codeword;
      dlsch0_harq       = dlsch_ue[codeword_TB0]->harq_processes[harq_pid];
      dlsch1_harq       = dlsch_ue[codeword_TB1]->harq_processes[harq_pid];
#ifdef DEBUG_HARQ
      printf("I am assuming both CW active\n");
#endif
    }
     else if ((dlsch_ue[0]->harq_processes[harq_pid]->status == ACTIVE) &&
              (dlsch_ue[1]->harq_processes[harq_pid]->status != ACTIVE) ) {
      codeword_TB0      = dlsch_ue[0]->harq_processes[harq_pid]->codeword;
      dlsch0_harq       = dlsch_ue[0]->harq_processes[harq_pid];
      dlsch1_harq       = NULL;
      codeword_TB1      = -1;
    }
     else if ((dlsch_ue[0]->harq_processes[harq_pid]->status != ACTIVE) &&
              (dlsch_ue[1]->harq_processes[harq_pid]->status == ACTIVE) ){
      codeword_TB1      = dlsch_ue[1]->harq_processes[harq_pid]->codeword;
      dlsch0_harq       = dlsch_ue[1]->harq_processes[harq_pid];
      dlsch1_harq       = NULL;
      codeword_TB0      = -1;
    }
    break;

  default:
    LOG_E(PHY,"[UE %d][FATAL] Frame %d subframe %d: Unknown PDSCH format %d\n",phy_vars_ue->frame_rx,subframe,type);
    return(-1);
    break;
  }
#ifdef DEBUG_HARQ
  printf("[DEMOD] MIMO mode = %d\n", dlsch0_harq->mimo_mode);
  printf("[DEMOD] cw for TB0 = %d, cw for TB1 = %d\n", codeword_TB0, codeword_TB1);
#endif

  DevAssert(dlsch0_harq);
  round = dlsch0_harq->round;

  if (eNB_id > 2) {
    LOG_W(PHY,"dlsch_demodulation.c: Illegal eNB_id %d\n",eNB_id);
    return(-1);
  }

  if (!lte_ue_common_vars) {
    LOG_W(PHY,"dlsch_demodulation.c: Null lte_ue_common_vars\n");
    return(-1);
  }

  if (!dlsch_ue[0]) {
    LOG_W(PHY,"dlsch_demodulation.c: Null dlsch_ue pointer\n");
    return(-1);
  }

  if (!lte_ue_pdsch_vars) {
    LOG_W(PHY,"dlsch_demodulation.c: Null lte_ue_pdsch_vars pointer\n");
    return(-1);
  }

  if (!frame_parms) {
    LOG_W(PHY,"dlsch_demodulation.c: Null lte_frame_parms\n");
    return(-1);
  }

  if (((frame_parms->Ncp == NORMAL) && (symbol>=7)) ||
      ((frame_parms->Ncp == EXTENDED) && (symbol>=6)))
    rballoc = dlsch0_harq->rb_alloc_odd;
  else
    rballoc = dlsch0_harq->rb_alloc_even;

  if (dlsch0_harq->mimo_mode>DUALSTREAM_PUSCH_PRECODING) {
    LOG_E(PHY,"This transmission mode is not yet supported!\n");
    return(-1);
  }



  if ((dlsch0_harq->mimo_mode==LARGE_CDD) || ((dlsch0_harq->mimo_mode>=DUALSTREAM_UNIFORM_PRECODING1) && (dlsch0_harq->mimo_mode<=DUALSTREAM_PUSCH_PRECODING)))  {
    DevAssert(dlsch1_harq);
    if (eNB_id!=eNB_id_i) {
      LOG_E(PHY,"TM3/TM4 requires to set eNB_id==eNB_id_i!\n");
      return(-1);
    }
  }

  //printf("rx_pdsch: harq_pid=%d, round=%d\n",harq_pid,round);

  if (frame_parms->nb_antennas_tx_eNB>1) {
    nb_rb = dlsch_extract_rbs_dual(lte_ue_common_vars->rxdataF,
                                   lte_ue_common_vars->dl_ch_estimates[eNB_id],
                                   lte_ue_pdsch_vars[eNB_id]->rxdataF_ext,
                                   lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                                   dlsch0_harq->pmi_alloc,
                                   lte_ue_pdsch_vars[eNB_id]->pmi_ext,
                                   rballoc,
                                   symbol,
                                   subframe,
                                   phy_vars_ue->high_speed_flag,
                                   frame_parms,
                                                           dlsch0_harq->mimo_mode);
//#ifdef DEBUG_DLSCH_MOD
    /*   printf("dlsch: using pmi %lx, rb_alloc %x, pmi_ext ",pmi2hex_2Ar1(dlsch0_harq->pmi_alloc),*rballoc);
       for (rb=0;rb<nb_rb;rb++)
          printf("%d",lte_ue_pdsch_vars[eNB_id]->pmi_ext[rb]);
       printf("\n");*/
//#endif

   if (rx_type >= rx_IC_single_stream) {
      if (eNB_id_i<phy_vars_ue->n_connected_eNB) // we are in TM5
       nb_rb = dlsch_extract_rbs_dual(lte_ue_common_vars->rxdataF,
                                       lte_ue_common_vars->dl_ch_estimates[eNB_id_i],
                                       lte_ue_pdsch_vars[eNB_id_i]->rxdataF_ext,
                                       lte_ue_pdsch_vars[eNB_id_i]->dl_ch_estimates_ext,
                                       dlsch0_harq->pmi_alloc,
                                       lte_ue_pdsch_vars[eNB_id_i]->pmi_ext,
                                       rballoc,
                                       symbol,
                                       subframe,
                                       phy_vars_ue->high_speed_flag,
                                       frame_parms,
                                                               dlsch0_harq->mimo_mode);
     else
       nb_rb = dlsch_extract_rbs_dual(lte_ue_common_vars->rxdataF,
                                       lte_ue_common_vars->dl_ch_estimates[eNB_id],
                                       lte_ue_pdsch_vars[eNB_id_i]->rxdataF_ext,
                                       lte_ue_pdsch_vars[eNB_id_i]->dl_ch_estimates_ext,
                                       dlsch0_harq->pmi_alloc,
                                       lte_ue_pdsch_vars[eNB_id_i]->pmi_ext,
                                       rballoc,
                                       symbol,
                                       subframe,
                                       phy_vars_ue->high_speed_flag,
                                       frame_parms,
                                                               dlsch0_harq->mimo_mode);
    }
  } // if n_tx>1
  else {
    nb_rb = dlsch_extract_rbs_single(lte_ue_common_vars->rxdataF,
                                     lte_ue_common_vars->dl_ch_estimates[eNB_id],
                                     lte_ue_pdsch_vars[eNB_id]->rxdataF_ext,
                                     lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                                     dlsch0_harq->pmi_alloc,
                                     lte_ue_pdsch_vars[eNB_id]->pmi_ext,
                                     rballoc,
                                     symbol,
                                     subframe,
                                     phy_vars_ue->high_speed_flag,
                                     frame_parms);
   if (rx_type==rx_IC_single_stream) {
     if (eNB_id_i<phy_vars_ue->n_connected_eNB)
        nb_rb = dlsch_extract_rbs_single(lte_ue_common_vars->rxdataF,
                                         lte_ue_common_vars->dl_ch_estimates[eNB_id_i],
                                         lte_ue_pdsch_vars[eNB_id_i]->rxdataF_ext,
                                         lte_ue_pdsch_vars[eNB_id_i]->dl_ch_estimates_ext,
                                         dlsch0_harq->pmi_alloc,
                                         lte_ue_pdsch_vars[eNB_id_i]->pmi_ext,
                                         rballoc,
                                         symbol,
                                         subframe,
                                         phy_vars_ue->high_speed_flag,
                                         frame_parms);

      else
        nb_rb = dlsch_extract_rbs_single(lte_ue_common_vars->rxdataF,
                                         lte_ue_common_vars->dl_ch_estimates[eNB_id],
                                         lte_ue_pdsch_vars[eNB_id_i]->rxdataF_ext,
                                         lte_ue_pdsch_vars[eNB_id_i]->dl_ch_estimates_ext,
                                         dlsch0_harq->pmi_alloc,
                                         lte_ue_pdsch_vars[eNB_id_i]->pmi_ext,
                                         rballoc,
                                         symbol,
                                         subframe,
                                         phy_vars_ue->high_speed_flag,
                                         frame_parms);
    }
  } //else n_tx>1

  //  printf("nb_rb = %d, eNB_id %d\n",nb_rb,eNB_id);
  if (nb_rb==0) {
    LOG_D(PHY,"dlsch_demodulation.c: nb_rb=0\n");
    return(-1);
  }


#ifdef DEBUG_PHY
    LOG_D(PHY,"[DLSCH] log2_maxh = %d (%d,%d)\n",lte_ue_pdsch_vars[eNB_id]->log2_maxh,avg[0],avgs);
    LOG_D(PHY,"[DLSCH] mimo_mode = %d\n", dlsch0_harq->mimo_mode);
#endif

  aatx = frame_parms->nb_antennas_tx_eNB;
  aarx = frame_parms->nb_antennas_rx;

  if (dlsch0_harq->mimo_mode<LARGE_CDD) {// SISO or ALAMOUTI


     dlsch_scale_channel(lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                          frame_parms,
                          dlsch_ue,
                          symbol,
                          nb_rb);

      if (first_symbol_flag==1) {
        dlsch_channel_level(lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                        frame_parms,
                        avg,
                        symbol,
                        nb_rb);
#ifdef DEBUG_PHY
    LOG_D(PHY,"[DLSCH] avg[0] %d\n",avg[0]);
#endif

    avgs = 0;

    for (aatx=0;aatx<frame_parms->nb_antennas_tx_eNB;aatx++)
      for (aarx=0;aarx<frame_parms->nb_antennas_rx;aarx++)
        avgs = cmax(avgs,avg[(aatx<<1)+aarx]);
    //  avgs = cmax(avgs,avg[(aarx<<1)+aatx]);

     lte_ue_pdsch_vars[eNB_id]->log2_maxh = (log2_approx(avgs)/2)+1; //+ interf_unaw_shift_tm1_mcs[dlsch0_harq->mcs];
   // printf("TM4 I-A log2_maxh0 = %d\n", lte_ue_pdsch_vars[eNB_id]->log2_maxh);
      }


        dlsch_channel_compensation(lte_ue_pdsch_vars[eNB_id]->rxdataF_ext,
                               lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                               lte_ue_pdsch_vars[eNB_id]->dl_ch_mag0,
                               lte_ue_pdsch_vars[eNB_id]->dl_ch_magb0,
                               lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0,
                               (aatx>1) ? lte_ue_pdsch_vars[eNB_id]->rho : NULL,
                               frame_parms,
                               symbol,
                               first_symbol_flag,
                               dlsch0_harq->Qm,
                               nb_rb,
                               lte_ue_pdsch_vars[eNB_id]->log2_maxh,
                               phy_measurements); // log2_maxh+I0_shift

 /*if (symbol == 5) {
     write_output("rxF_comp_d.m","rxF_c_d",&lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0[0][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);
 } */
    if ((rx_type==rx_IC_single_stream) &&
        (eNB_id_i<phy_vars_ue->n_connected_eNB)) {

         dlsch_channel_compensation(lte_ue_pdsch_vars[eNB_id_i]->rxdataF_ext,
                                 lte_ue_pdsch_vars[eNB_id_i]->dl_ch_estimates_ext,
                                 lte_ue_pdsch_vars[eNB_id_i]->dl_ch_mag0,
                                 lte_ue_pdsch_vars[eNB_id_i]->dl_ch_magb0,
                                 lte_ue_pdsch_vars[eNB_id_i]->rxdataF_comp0,
                                 (aatx>1) ? lte_ue_pdsch_vars[eNB_id_i]->rho : NULL,
                                 frame_parms,
                                 symbol,
                                 first_symbol_flag,
                                 i_mod,
                                 nb_rb,
                                 lte_ue_pdsch_vars[eNB_id]->log2_maxh,
                                 phy_measurements); // log2_maxh+I0_shift
#ifdef DEBUG_PHY

      if (symbol == 5) {
        write_output("rxF_comp_d.m","rxF_c_d",&lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0[0][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);

        write_output("rxF_comp_i.m","rxF_c_i",&lte_ue_pdsch_vars[eNB_id_i]->rxdataF_comp0[0][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);
      }
#endif
     // compute correlation between signal and interference channels
      dlsch_dual_stream_correlation(frame_parms,
                                    symbol,
                                    nb_rb,
                                    lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                                    lte_ue_pdsch_vars[eNB_id_i]->dl_ch_estimates_ext,
                                    lte_ue_pdsch_vars[eNB_id]->dl_ch_rho_ext[harq_pid][round],
                                    lte_ue_pdsch_vars[eNB_id]->log2_maxh);
    }

  }
  else if ((dlsch0_harq->mimo_mode == LARGE_CDD) ||
           ((dlsch0_harq->mimo_mode >=DUALSTREAM_UNIFORM_PRECODING1) &&
            (dlsch0_harq->mimo_mode <=DUALSTREAM_PUSCH_PRECODING))){  // TM3 or TM4
    //   LOG_I(PHY,"Running PDSCH RX for TM3\n");

    if (frame_parms->nb_antennas_tx_eNB == 2) {


         // scaling interfering channel (following for TM56)
        dlsch_scale_channel(lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                            frame_parms,
                            dlsch_ue,
                            symbol,
                            nb_rb);


      if (first_symbol_flag==1) {
        // effective channel of desired user is always stronger than interfering eff. channel
        dlsch_channel_level_TM34(lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                                 frame_parms,
                                 lte_ue_pdsch_vars[eNB_id]->pmi_ext,
                                 avg_0,
                                 avg_1,
                                 symbol,
                                 nb_rb,
                                 dlsch0_harq->mimo_mode);



 //  write_output("dlsch0_r0_aver_chan_1.m","dl_aver_ch1_r0_0",&avg_1[0],1,1,2);


        if (rx_type>rx_standard) {
        // Shifts are needed to avoid tails in SNR/BLER curves.
        // LUT will be introduced with mcs-dependent shift
        avg_0[0] = (log2_approx(avg_0[0])/2) -13 + interf_unaw_shift;
        avg_1[0] = (log2_approx(avg_1[0])/2) -13 + interf_unaw_shift;
        lte_ue_pdsch_vars[eNB_id]->log2_maxh0 = cmax(avg_0[0],0);
        lte_ue_pdsch_vars[eNB_id]->log2_maxh1 = cmax(avg_1[0],0);

        //printf("TM4 I-A log2_maxh0 = %d\n", lte_ue_pdsch_vars[eNB_id]->log2_maxh0);
        //printf("TM4 I-A log2_maxh1 = %d\n", lte_ue_pdsch_vars[eNB_id]->log2_maxh1);

         }
        else {
        // Shifts are needed to avoid tails in SNR/BLER curves.
        // LUT will be introduced with mcs-dependent shift
        avg_0[0] = (log2_approx(avg_0[0])/2) - 13 + interf_unaw_shift;
        avg_1[0] = (log2_approx(avg_1[0])/2) - 13 + interf_unaw_shift;
        lte_ue_pdsch_vars[eNB_id]->log2_maxh0 = cmax(avg_0[0],0);
        lte_ue_pdsch_vars[eNB_id]->log2_maxh1 = cmax(avg_1[0],0);
        //printf("TM4 I-UA log2_maxh0 = %d\n", lte_ue_pdsch_vars[eNB_id]->log2_maxh0);
        //printf("TM4 I-UA log2_maxh1 = %d\n", lte_ue_pdsch_vars[eNB_id]->log2_maxh1);
        }
      }

      dlsch_channel_compensation_TM34(frame_parms,
                                     lte_ue_pdsch_vars[eNB_id],
                                     phy_measurements,
                                     eNB_id,
                                     symbol,
                                     dlsch0_harq->Qm,
                                     dlsch1_harq->Qm,
                                     harq_pid,
                                     dlsch0_harq->round,
                                     dlsch0_harq->mimo_mode,
                                     nb_rb,
                                     lte_ue_pdsch_vars[eNB_id]->log2_maxh0,
                                     lte_ue_pdsch_vars[eNB_id]->log2_maxh1);

  /*   if (symbol == 5) {

     write_output("rxF_comp_d00.m","rxF_c_d00",&lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0[0][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);// should be QAM
     write_output("rxF_comp_d01.m","rxF_c_d01",&lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0[1][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);//should be almost 0
     write_output("rxF_comp_d10.m","rxF_c_d10",&lte_ue_pdsch_vars[eNB_id]->rxdataF_comp1[harq_pid][round][0][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);//should be almost 0
     write_output("rxF_comp_d11.m","rxF_c_d11",&lte_ue_pdsch_vars[eNB_id]->rxdataF_comp1[harq_pid][round][1][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);//should be QAM


        } */

      // compute correlation between signal and interference channels (rho12 and rho21)

        dlsch_dual_stream_correlation(frame_parms, // this is doing h11'*h12 and h21'*h22
                                    symbol,
                                    nb_rb,
                                    lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                                    &(lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext[2]),
                                    lte_ue_pdsch_vars[eNB_id]->dl_ch_rho2_ext,
                                    lte_ue_pdsch_vars[eNB_id]->log2_maxh0);

        //printf("rho stream1 =%d\n", &lte_ue_pdsch_vars[eNB_id]->dl_ch_rho_ext[harq_pid][round] );

      //to be optimized (just take complex conjugate)

      dlsch_dual_stream_correlation(frame_parms, // this is doing h12'*h11 and h22'*h21
                                    symbol,
                                    nb_rb,
                                    &(lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext[2]),
                                    lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                                    lte_ue_pdsch_vars[eNB_id]->dl_ch_rho_ext[harq_pid][round],
                                    lte_ue_pdsch_vars[eNB_id]->log2_maxh1);
    //  printf("rho stream2 =%d\n",&lte_ue_pdsch_vars[eNB_id]->dl_ch_rho2_ext );
      //printf("TM3 log2_maxh : %d\n",lte_ue_pdsch_vars[eNB_id]->log2_maxh);

  /*     if (symbol == 5) {

     write_output("rho0_0.m","rho0_0",&lte_ue_pdsch_vars[eNB_id]->dl_ch_rho_ext[harq_pid][round][0][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);// should be QAM
     write_output("rho2_0.m","rho2_0",&lte_ue_pdsch_vars[eNB_id]->dl_ch_rho2_ext[0][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);//should be almost 0
     write_output("rho0_1.m.m","rho0_1",&lte_ue_pdsch_vars[eNB_id]->dl_ch_rho_ext[harq_pid][round][1][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);//should be almost 0
     write_output("rho2_1.m","rho2_1",&lte_ue_pdsch_vars[eNB_id]->dl_ch_rho2_ext[1][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);//should be QAM


        } */

   }
      else {
     LOG_E(PHY, "only 2 tx antennas supported for TM3\n");
      return(-1);
    }
  }
  else if (dlsch0_harq->mimo_mode<DUALSTREAM_UNIFORM_PRECODING1) {// single-layer precoding (TM5, TM6)
   //    printf("Channel compensation for precoding\n");
    if ((rx_type==rx_IC_single_stream) && (eNB_id_i==phy_vars_ue->n_connected_eNB) && (dlsch0_harq->dl_power_off==0)) {  // TM5 two-user

      // Scale the channel estimates for interfering stream

       dlsch_scale_channel(lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                          frame_parms,
                          dlsch_ue,
                          symbol,
                          nb_rb);

      dlsch_scale_channel(lte_ue_pdsch_vars[eNB_id_i]->dl_ch_estimates_ext,
                          frame_parms,
                          dlsch_ue,
                          symbol,
                          nb_rb);

      /* compute new log2_maxh for effective channel */
      if (first_symbol_flag==1) {

        // effective channel of desired user is always stronger than interfering eff. channel
       dlsch_channel_level_TM56(lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                                frame_parms,
                                lte_ue_pdsch_vars[eNB_id]->pmi_ext,
                                avg,
                                symbol,
                                nb_rb);

        //    LOG_D(PHY,"llr_offset = %d\n",offset_mumimo_llr_drange[dlsch0_harq->mcs][(i_mod>>1)-1]);
        avg[0] = log2_approx(avg[0]) - 13 + offset_mumimo_llr_drange[dlsch0_harq->mcs][(i_mod>>1)-1];

        lte_ue_pdsch_vars[eNB_id]->log2_maxh = cmax(avg[0],0);
        //printf("log1_maxh =%d\n",lte_ue_pdsch_vars[eNB_id]->log2_maxh);
      }

      dlsch_channel_compensation_TM56(lte_ue_pdsch_vars[eNB_id]->rxdataF_ext,
                                      lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                                      lte_ue_pdsch_vars[eNB_id]->dl_ch_mag0,
                                      lte_ue_pdsch_vars[eNB_id]->dl_ch_magb0,
                                      lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0,
                                      lte_ue_pdsch_vars[eNB_id]->pmi_ext,
                                      frame_parms,
                                      phy_measurements,
                                      eNB_id,
                                      symbol,
                                      dlsch0_harq->Qm,
                                      nb_rb,
                                      lte_ue_pdsch_vars[eNB_id]->log2_maxh,
                                      dlsch0_harq->dl_power_off);

      // if interference source is MU interference, assume opposite precoder was used at eNB

      // calculate opposite PMI
      for (rb=0; rb<nb_rb; rb++) {

        switch(lte_ue_pdsch_vars[eNB_id]->pmi_ext[rb]) {
        case 0:
          lte_ue_pdsch_vars[eNB_id_i]->pmi_ext[rb]=1;
          break;
       case 1:
          lte_ue_pdsch_vars[eNB_id_i]->pmi_ext[rb]=0;
          break;
       case 2:
          lte_ue_pdsch_vars[eNB_id_i]->pmi_ext[rb]=3;
          break;
        case 3:
          lte_ue_pdsch_vars[eNB_id_i]->pmi_ext[rb]=2;
          break;
        }

       //  if (rb==0)
        //    printf("pmi %d, pmi_i %d\n",lte_ue_pdsch_vars[eNB_id]->pmi_ext[rb],lte_ue_pdsch_vars[eNB_id_i]->pmi_ext[rb]);

      }


      dlsch_channel_compensation_TM56(lte_ue_pdsch_vars[eNB_id_i]->rxdataF_ext,
                                      lte_ue_pdsch_vars[eNB_id_i]->dl_ch_estimates_ext,
                                      lte_ue_pdsch_vars[eNB_id_i]->dl_ch_mag0,
                                      lte_ue_pdsch_vars[eNB_id_i]->dl_ch_magb0,
                                      lte_ue_pdsch_vars[eNB_id_i]->rxdataF_comp0,
                                      lte_ue_pdsch_vars[eNB_id_i]->pmi_ext,
                                      frame_parms,
                                      phy_measurements,
                                      eNB_id_i,
                                      symbol,
                                      i_mod,
                                      nb_rb,
                                      lte_ue_pdsch_vars[eNB_id]->log2_maxh,
                                      dlsch0_harq->dl_power_off);


#ifdef DEBUG_PHY

      if (symbol==5) {
        write_output("rxF_comp_d.m","rxF_c_d",&lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0[0][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);
       write_output("rxF_comp_i.m","rxF_c_i",&lte_ue_pdsch_vars[eNB_id_i]->rxdataF_comp0[0][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);
      }
#endif
      dlsch_dual_stream_correlation(frame_parms,
                                    symbol,
                                    nb_rb,
                                    lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                                    lte_ue_pdsch_vars[eNB_id_i]->dl_ch_estimates_ext,
                                    lte_ue_pdsch_vars[eNB_id]->dl_ch_rho_ext[harq_pid][round],
                                    lte_ue_pdsch_vars[eNB_id]->log2_maxh);

    }
    else if (dlsch0_harq->dl_power_off==1)  {

        dlsch_scale_channel(lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                          frame_parms,
                          dlsch_ue,
                          symbol,
                          nb_rb);

      if (first_symbol_flag==1) {

        dlsch_channel_level(lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                            frame_parms,
                            avg,
                            symbol,
                            nb_rb);
#ifdef DEBUG_PHY
    LOG_D(PHY,"[DLSCH] avg[0] %d\n",avg[0]);
#endif

        avgs = 0;

        for (aatx=0;aatx<frame_parms->nb_antennas_tx_eNB;aatx++)
          for (aarx=0;aarx<frame_parms->nb_antennas_rx;aarx++)
            avgs = cmax(avgs,avg[(aatx<<1)+aarx]);
        //  avgs = cmax(avgs,avg[(aarx<<1)+aatx]);

        lte_ue_pdsch_vars[eNB_id]->log2_maxh = (log2_approx(avgs)/2) + 1;
        lte_ue_pdsch_vars[eNB_id]->log2_maxh++;

      }


      dlsch_channel_compensation_TM56(lte_ue_pdsch_vars[eNB_id]->rxdataF_ext,
                                      lte_ue_pdsch_vars[eNB_id]->dl_ch_estimates_ext,
                                      lte_ue_pdsch_vars[eNB_id]->dl_ch_mag0,
                                      lte_ue_pdsch_vars[eNB_id]->dl_ch_magb0,
                                      lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0,
                                      lte_ue_pdsch_vars[eNB_id]->pmi_ext,
                                      frame_parms,
                                      phy_measurements,
                                      eNB_id,
                                      symbol,
                                      dlsch0_harq->Qm,
                                      nb_rb,
                                      lte_ue_pdsch_vars[eNB_id]->log2_maxh,
                                      1);

    }
  }

  //  printf("MRC\n");
  if (frame_parms->nb_antennas_rx > 1) {
    if ((dlsch0_harq->mimo_mode == LARGE_CDD) ||
        ((dlsch0_harq->mimo_mode >=DUALSTREAM_UNIFORM_PRECODING1) &&
         (dlsch0_harq->mimo_mode <=DUALSTREAM_PUSCH_PRECODING))){  // TM3 or TM4
      if (frame_parms->nb_antennas_tx_eNB == 2) {

        dlsch_detection_mrc_TM34(frame_parms,
                                 lte_ue_pdsch_vars[eNB_id],
                                 harq_pid,
                                 dlsch0_harq->round,
                                 symbol,
                                 nb_rb,
                                 1);


    /*   if (symbol == 5) {

     write_output("rho0_mrc.m","rho0_0",&lte_ue_pdsch_vars[eNB_id]->dl_ch_rho_ext[harq_pid][round][0][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);// should be QAM
     write_output("rho2_mrc.m","rho2_0",&lte_ue_pdsch_vars[eNB_id]->dl_ch_rho2_ext[0][symbol*frame_parms->N_RB_DL*12],frame_parms->N_RB_DL*12,1,1);//should be almost 0
        } */


      }
    } else {

      dlsch_detection_mrc(frame_parms,
                          lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0,
                          lte_ue_pdsch_vars[eNB_id_i]->rxdataF_comp0,
                          lte_ue_pdsch_vars[eNB_id]->rho,
                          lte_ue_pdsch_vars[eNB_id]->dl_ch_rho_ext[harq_pid][round],
                          lte_ue_pdsch_vars[eNB_id]->dl_ch_mag0,
                          lte_ue_pdsch_vars[eNB_id]->dl_ch_magb0,
                          lte_ue_pdsch_vars[eNB_id_i]->dl_ch_mag0,
                          lte_ue_pdsch_vars[eNB_id_i]->dl_ch_magb0,
                          symbol,
                          nb_rb,
                          rx_type==rx_IC_single_stream);
    }
  }

  //  printf("Combining");
  if ((dlsch0_harq->mimo_mode == SISO) ||
      ((dlsch0_harq->mimo_mode >= UNIFORM_PRECODING11) &&
       (dlsch0_harq->mimo_mode <= PUSCH_PRECODING0))) {

    /*
      dlsch_siso(frame_parms,
      lte_ue_pdsch_vars[eNB_id]->rxdataF_comp,
      lte_ue_pdsch_vars[eNB_id_i]->rxdataF_comp,
      symbol,
      nb_rb);
    */
  } else if (dlsch0_harq->mimo_mode == ALAMOUTI) {

    dlsch_alamouti(frame_parms,
                   lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0,
                   lte_ue_pdsch_vars[eNB_id]->dl_ch_mag0,
                   lte_ue_pdsch_vars[eNB_id]->dl_ch_magb0,
                   symbol,
                   nb_rb);

  }

  //    printf("LLR");
  if ((dlsch0_harq->mimo_mode == LARGE_CDD) ||
      ((dlsch0_harq->mimo_mode >=DUALSTREAM_UNIFORM_PRECODING1) &&
       (dlsch0_harq->mimo_mode <=DUALSTREAM_PUSCH_PRECODING)))  {
    rxdataF_comp_ptr = lte_ue_pdsch_vars[eNB_id]->rxdataF_comp1[harq_pid][round];
    dl_ch_mag_ptr = lte_ue_pdsch_vars[eNB_id]->dl_ch_mag1[harq_pid][round];
  }
  else {
    rxdataF_comp_ptr = lte_ue_pdsch_vars[eNB_id_i]->rxdataF_comp0;
    dl_ch_mag_ptr = lte_ue_pdsch_vars[eNB_id_i]->dl_ch_mag0;
    //i_mod should have been passed as a parameter
  }

  switch (dlsch0_harq->Qm) {
  case 2 :
    if ((rx_type==rx_standard) || (codeword_TB0 = 1)) {
        dlsch_qpsk_llr(frame_parms,
                       lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0,
                       lte_ue_pdsch_vars[eNB_id]->llr[0],
                       symbol,first_symbol_flag,nb_rb,
                       adjust_G2(frame_parms,dlsch0_harq->rb_alloc_even,2,subframe,symbol),
                       lte_ue_pdsch_vars[eNB_id]->llr128);
    }
      else if (rx_type >= rx_IC_single_stream) {
        if (dlsch1_harq->Qm == 2) {
          dlsch_qpsk_qpsk_llr(frame_parms,
                              lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0,
                              rxdataF_comp_ptr,
                              lte_ue_pdsch_vars[eNB_id]->dl_ch_rho2_ext,
                              lte_ue_pdsch_vars[eNB_id]->llr[0],
                              symbol,first_symbol_flag,nb_rb,
                              adjust_G2(frame_parms,dlsch0_harq->rb_alloc_even,2,subframe,symbol),
                              lte_ue_pdsch_vars[eNB_id]->llr128);
          if (rx_type==rx_IC_dual_stream) {
            dlsch_qpsk_qpsk_llr(frame_parms,
                                rxdataF_comp_ptr,
                                lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0,
                                lte_ue_pdsch_vars[eNB_id]->dl_ch_rho_ext[harq_pid][round],
                                lte_ue_pdsch_vars[eNB_id]->llr[1],
                                symbol,first_symbol_flag,nb_rb,
                                adjust_G2(frame_parms,dlsch1_harq->rb_alloc_even,2,subframe,symbol),
                                lte_ue_pdsch_vars[eNB_id]->llr128_2ndstream);
          }
        }
        else if (dlsch1_harq->Qm == 4) {
          dlsch_qpsk_16qam_llr(frame_parms,
                               lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0,
                               rxdataF_comp_ptr,//i
                               dl_ch_mag_ptr,//i
                               lte_ue_pdsch_vars[eNB_id]->dl_ch_rho2_ext,
                               lte_ue_pdsch_vars[eNB_id]->llr[0],
                               symbol,first_symbol_flag,nb_rb,
                               adjust_G2(frame_parms,dlsch0_harq->rb_alloc_even,2,subframe,symbol),
                               lte_ue_pdsch_vars[eNB_id]->llr128);
          if (rx_type==rx_IC_dual_stream) {
            dlsch_16qam_qpsk_llr(frame_parms,
                                 rxdataF_comp_ptr,
                                 lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0,//i
                                 dl_ch_mag_ptr,
                                 lte_ue_pdsch_vars[eNB_id]->dl_ch_rho_ext[harq_pid][round],
                                 lte_ue_pdsch_vars[eNB_id]->llr[1],
                                 symbol,first_symbol_flag,nb_rb,
                                 adjust_G2(frame_parms,dlsch1_harq->rb_alloc_even,4,subframe,symbol),
                                 lte_ue_pdsch_vars[eNB_id]->llr128_2ndstream);
          }
        }
        else {
          dlsch_qpsk_64qam_llr(frame_parms,
                               lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0,
                               rxdataF_comp_ptr,//i
                               dl_ch_mag_ptr,//i
                               lte_ue_pdsch_vars[eNB_id]->dl_ch_rho2_ext,
                               lte_ue_pdsch_vars[eNB_id]->llr[0],
                               symbol,first_symbol_flag,nb_rb,
                               adjust_G2(frame_parms,dlsch0_harq->rb_alloc_even,2,subframe,symbol),
                               lte_ue_pdsch_vars[eNB_id]->llr128);
          if (rx_type==rx_IC_dual_stream) {
            dlsch_64qam_qpsk_llr(frame_parms,
                                 rxdataF_comp_ptr,
                                 lte_ue_pdsch_vars[eNB_id]->rxdataF_comp0,//i
                                 dl_ch_mag_ptr,
                                 lte_ue_pdsch_vars[eNB_id]->dl_ch_rho_ext[harq_pid][round],
                                 lte_ue_pdsch_vars[eNB_id]->llr[1],
                                 symbol,first_symbol_flag,nb_rb,
                                 adjust_G2(frame_parms,dlsch1_harq->rb_alloc_even,6,subframe,symbol),
                                 lte_ue_pdsch_vars[eNB_id]->llr128_2ndstream);
          }
        }
      }
    break;
  case 4 :
    if ((rx_type==rx_standard ) || (codeword_TB0 = 1) ) {