cyclint.c

用C语言编写的交织器

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

// File: cyclint.c

// Description: Generate a CYCLIC interleaver. The output is an interleaver

// array in a file with name specified at command input line.

// Example: N1=3 N2=5 D=2

//

//                   0   3   6   9  12 

//                   1   4   7  10  13 

//                   2   5   8  11  14 

//

// Delay:

//                   0   3   6   9  12 

//                  10  13   1   4   7 

//                   5   8  11  14   2 

//

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

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



#include <stdio.h>

#include <math.h>

#include <float.h>

#include <limits.h>

#define NMAX 16384

#define NM2    512



main(int argc, char *argv[])

{



int interleaver[NMAX];

int array[NM2][NM2];

int temp[NMAX];

int i, j, position;

int N1, N2;

int N;                                 // Interleaver length

int D;                                 // Delay, see text p. 116

char name1[40];

FILE *fp1;



  // Command line processing

  if (argc != 5)

    {

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

      exit(0);

    }



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

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

  sscanf(argv[3],"%d", &D);

  sscanf(argv[4],"%s", name1);



  N = N1*N2;



  fp1 = fopen(name1,"w");



  // Write columnwise

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

    array[i%N1][i/N1] = i;



  for (i=0; i<N1; i++) {

    for (j=0; j<N2; j++)

      printf("%3d ", array[i][j]);

    printf("\n");

    }

  printf("\n");



  for (i=0; i<N1; i++) 

    {

      for (j=0; j<N2; j++)

        temp[j] = array[i][j];

      for (j=0; j<N2; j++)

        array[i][(i*D+j)%N2] = temp[j];

    }



  for (i=0; i<N1; i++) {

    for (j=0; j<N2; j++)

      printf("%3d ", array[i][j]);

    printf("\n");

    }

  printf("\n");



  // Read off columnwise

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

    {

      position = array[i%N1][i/N1];

      interleaver[i] = position;

    }    



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

    {

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

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

    }



  fclose(fp1);



}