/*****************************************************************************//*   FIle Name : dft64.c                                                     *//*   Description : WiMax-OFDM DFT  for Preamble detection                    *//*   author : miffie                                                         *//*   Date   : Nov/09/05                                                      *//*   Copyright (c) 2005 miffie   All rights reserved.                        *//*****************************************************************************/struct complexset dft64 (struct complexset datain ) {int 	nn , kk ;struct 	complexset cset ;struct  complex    *top , *p ;struct  complex    tmp1, tmp2 ;double  p1 ;  //Main     PRINTF("dft64 size=%d\n", datain.size ) ;    if ((top = (struct complex *)malloc(64*sizeof(struct complex)) ) == NULL) {        PRINTF( " malloc failed in dft64.c\n") ;    } //fail    else { //allocated     for(kk=-32;kk<=31;kk++) { //each sample       //pilot       tmp1.realp = 0 ;       tmp1.image = 0 ;       p= datain.data ;       for(nn=0;nn<=63;nn++) { //each subcarrier         p1 = 2*pi*nn*kk/64 ;         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 ;     } //each sample     cset.size = 64 ;     cset.data = top ;    }//allocated    //free ( datain.data ) ;    return ( cset ) ;} //dft64