interleaver.c

来自「This model is just testing an idea of MI」· C语言 代码 · 共 51 行

/*****************************************************************************/
/*   FIle Name : interleaver.c                                               */
/*   Description : WLAN FEC interleaver for Encoder                          */
/*                 1st : i=(Ncbps/16)(kmod 16) + floor(k/16)                 */
/*                 2nd : j=s*floor(i/s) + (i+Ncbps-floor(16*i/Ncbps))mod s   */
/*   author : miffie                                                         */
/*   Date   : aug/05/05                                                      */
/*   Copyright (c) 2005 miffie   All rights reserved.                          */
/*****************************************************************************/
struct binaryset interleaver (struct binaryset datain, char Nbpsc ) {
int 	ii , pp ;
char 	shifter ;
char 	tmp1 ;
struct 	binaryset bset ;
char    *top1, *top2 ;
//Ncbps is same as datain.size
  //Main 
    PRINTF("interleaver size=%d\n", datain.size ) ;
    if (((top1 = (char *)malloc(datain.size*sizeof(char)) ) == NULL) |
        ((top2 = (char *)malloc(datain.size*sizeof(char)) ) == NULL)) {
        PRINTF( " malloc failed in interleaver.c\n") ;
    } //fail
    else { //allocated
     //permutation1
     for(ii=0;ii<datain.size;ii++) { //p1
      pp = (datain.size/16) * (ii % 16) + (ii/16) ;
      //printf("permutation1 %d %d\n", ii, pp  ) ;
      top1[ pp ] =  datain.data[ ii ] ;
      //printf(" top1(%d)=%d \n", pp, top1[pp] ) ;
     } //p1

     //permutation2
     tmp1 = 1 ;
     if ((Nbpsc/2)>tmp1)  tmp1 = (Nbpsc/2) ;
     for(ii=0;ii<datain.size;ii++) { //p2
      pp = tmp1* (ii/tmp1) + 
            ( ii + datain.size - (16*ii/datain.size)) % tmp1 ;
      //printf("permutation2 %d %d\n", ii, pp ) ;
      top2[ pp ] =  top1[ ii ] ;
      //printf(" top2(%d)=%d \n", pp, top2[pp] ) ;
     } //p2

     bset.format = 0 ;
     bset.size = datain.size ;
     bset.data = top2 ;
    }//allocated
    free( top1 ) ;
    free( datain.data ) ;
    return ( bset ) ;
} //interleaver