dft8.c

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

/*****************************************************************************/
/*   FIle Name : dft8.c                                                     */
/*   Description : WLAN OFDM DFT  for Decoder                                */
/*   author : miffie                                                         */
/*   Date   : aug/19/05                                                      */
/*   Copyright (c) 2005 miffie   All rights reserved.                          */
/*****************************************************************************/
struct complex dft8 (struct complexset datain ) {

int 	nn , kk ;
struct 	complexset cset ;
struct  complex    *top , *p ;
struct  complex    tmp1, tmp2 ;
double  p1 ;

  //Main 
    PRINTF("dft8 size=%d\n", datain.size ) ;
    kk=1 ;
       //pilot
       tmp1.realp = 0 ;
       tmp1.image = 0 ;
       p= datain.data ;
       for(nn=0;nn<=7;nn++) { //each subcarrier
         p1 = 2*pi*nn*kk/8 ;
         tmp2.realp = cos( p1 ) ;
         tmp2.image = -sin( p1 ) ;
         tmp2 = multiply_complex(*p++ , tmp2) ;
         tmp1.realp += tmp2.realp ;
         tmp1.image += tmp2.image ;
       }//each subcarrier
       top[kk+32].realp = tmp1.realp ;
       top[kk+32].image = tmp1.image ;
    //free ( datain.data ) ;
    return ( tmp1 ) ;

} //dft64