mimo_dfe.c

This model is just testing an idea of MIMO, which IEEE802.11n will have. But I havo not seen the s

/*****************************************************************************/
/*   FIle Name : mimo_dfe.c                                                  */
/*   Description : MIMO prototype Decision Feedback Equalizer for MIMO       */
/*   author : miffie                                                         */
/*   Date   : oct/28/05                                                      */
/*   Copyright (c) 2005 miffie   All rights reserved.                        */
/*****************************************************************************/

struct complexsetset mimo_dfe(struct complexsetset css , char num_out ) 
{ //mimo_dfe
int ii, jj, kk ;
int size , offset ;
struct complexset *ctop ;
struct complexset cset0 ;
struct complexsetset cout ;
struct complex yy , tmp1, error ;
struct complex coef[8] ;
struct complex *top ;

double  mu = 2.0 ;


static double short_realp[] = {  0.046 , -0.132 , -0.013 ,  0.143,
                                 0.092 ,  0.143 , -0.013 , -0.132,
                                 0.046 ,  0.002 , -0.079 , -0.013,
                                 0.000 , -0.013 , -0.079 ,  0.002 } ;

static double short_image[] = {  0.046 ,  0.002 , -0.079 , -0.013,
                                 0.000 , -0.013 , -0.079 ,  0.002,
                                 0.046 , -0.132 , -0.013 ,  0.143,
                                 0.092 ,  0.143 , -0.013 , -0.132 } ;
 
  if((ctop = (struct complexset *)malloc(num_out*sizeof(struct complexset)) ) == NULL) {
        PRINTF( " malloc failed in mimo_dfe.c\n") ;
  } //fail
  else { //allocated

    size  = css.set[0].size ;
    cout.size = num_out ;
    cout.set = ctop ;

    PRINTF("mimo_dfe num_out=%d size=%d\n", num_out, size ) ;
    for(kk=0;kk<num_out;kk++) { //each transmitter
      if ((top = (struct complex *)malloc(size*sizeof(struct complex)) ) == NULL) {
        PRINTF( " malloc failed in mimo_dfe.c\n") ;
      } //fail
      else { //allocated
        ctop[kk].data =  top ;
        ctop[kk].size =  size-8 ;
        //initialize coeffcients
        for(jj=0;jj<css.size;jj++) { 
          coef[jj].realp = 0 ;
          coef[jj].image = 0 ;
        } 
        offset = kk * 2 ;
        for(ii=0;ii<(size-8);ii++) { //each sample
          yy.realp = 0 ;
          yy.image = 0 ;
          for(jj=0;jj<css.size;jj++) { //each receiver
             //printf("data(%d %d) r=%6.3f i=%6.3f\n", ii, jj, css.set[jj].data[ii+offset].realp, 
             //                                        css.set[jj].data[ii+offset].image ) ;
             tmp1 = multiply_complex(coef[jj] ,css.set[jj].data[ii+offset]) ;
             yy.realp += tmp1.realp ;
             yy.image += tmp1.image ;
          } //each receiver

          //Output
           top[ii].realp = yy.realp ;
           top[ii].image = yy.image ;
           printf("yy(%d) r=%6.3f i=%6.3f\n", ii, yy.realp, yy.image) ;
  
          if(ii<160) { //training mode
          //
          mu = (ii<60) ? 8.0 : 1.0 ;
          //Compare SHORT Sequence
           //Error
             printf("exp(%d) r=%6.3f i=%6.3f\n", ii, short_realp[ ii %16 ], short_image[ ii %16 ]  ) ;
             error.realp = (short_realp[ ii %16 ] - yy.realp)*mu ;
             error.image = (short_image[ ii %16 ] - yy.image)*mu ;
             //printf("error(%d) r=%6.3f i=%6.3f\n", ii, error.realp, error.image) ;
  
          //Coef for the next cycles
            for(jj=0;jj<css.size;jj++) { //each receiver
              tmp1.realp = css.set[jj].data[ii+offset].realp ;
              tmp1.image = -css.set[jj].data[ii+offset].image ;
              tmp1 = multiply_complex(error, tmp1 ) ;
              coef[jj].realp += tmp1.realp ;
              coef[jj].image += tmp1.image ;
              printf("coef(%d %d) %6.3f + j * %6.3f\n",ii, jj,  coef[jj].realp, coef[jj].image) ;
            } //each receiver
          } //training mode
        } //each sample
      } //allocated
    } //each transmitter
  } //allocated
  return( cout ) ;
}//mimo_dfe