helint.c

用C语言编写的交织器

// ------------------------------------------------------------------------

// File: helint.c

// Description: Generate a HELICAL interleaver. Output is the interleaver

// array in a files with name specified at command line

//

// Example: N1=3 N2=5

//

//                   0  1  2  3  4

//                   5  6  7  8  9

//                  10 11 12 13 14

//

//                i   0  1  2  3  4  5  6  7  8  9 10 11 12 13 14

//    interleaver[i]  0  6 12  3  9 10  1  7 13  4  5 11  2  8 14



#include <stdio.h>

#include <math.h>

#include <float.h>

#include <limits.h>

#define NMAX 16384



main(int argc, char *argv[])

{



int interleaver[NMAX];

int i, position;

int N1, N2;

int N;                                 // Interleaver length

char name1[40];

FILE *fp1;



  // Command line processing

  if (argc != 4)

    {

      printf("Usage %s N1  N2  INT_file\n", argv[0]);

      exit(0);

    }



  sscanf(argv[1],"%d", &N1);

  sscanf(argv[2],"%d", &N2);

  sscanf(argv[3],"%s", name1);



  N = N1*N2;



  fp1 = fopen(name1,"w");



  for (i=0; (i<N); i++)

    {

      position = ( (i%N2)+ (i*N2) ) % N;

      interleaver[i] = position;

    }    



  for (i=0; i<N; i++)

    {

      fprintf(fp1, "%d\n", interleaver[i]);

      printf("%5d -> %5d\n",i,interleaver[i]);

    }



  fclose(fp1);



}