test_gold.c

伪随机gold序列产生程序

/*
 * $Log: test_gold.c,v $
 * Revision 1.1  2000/05/03 14:30:04  bjc97r
 * Initial revision
 *
 */
char *id = "$Id: test_gold.c,v 1.1 2000/05/03 14:30:04 bjc97r Exp $";


#include <stdio.h>
#include <stdlib.h>

#include "gold.h"

int main( int argc, char *argv[] )
  /* This program shows how to use gold*() functions to generate
     Gold codes */
{
  unsigned deg;
  ulong poly0, poly1;

  Gold *pn00, *pn01;
  Gold *pn10, *pn11;

  unsigned pn_size;
  unsigned offset;

  if ( argc != 4 ) {
    fprintf(stderr, "%s: deg poly poly1\n", argv[0] );
    fprintf(stderr, " Try, for example,\n" );
    fprintf(stderr, "   %s 5 045 075\n", argv[0] );
    fprintf(stderr, "   %s 23 040000041 040404041\n", argv[0] );
    exit(1);
  }

  deg = atoi( argv[1] );
  if ( deg < 2 ) {
    fprintf(stderr, "deg should be greater than 2\n");
    exit(1);
  }

  poly0 = strtoul( argv[2], (char**)NULL, 0 );
  if ( poly0 < 7 ) {
    fprintf(stderr, "poly(%s) is invalid polynomial!\n", argv[2] );
    exit(1);
  }

  poly1 = strtoul( argv[3], (char**)NULL, 0 );
  if ( poly1 < 7 ) {
    fprintf(stderr, "poly1(%s) is invalid polynomial!\n", argv[3] );
    exit(1);
  }

  // Print the header.
  printf("The entered Gold code specification is\n\n");
  printf("  degree      : %d\n", deg);
  printf("  poly0(octal): 0%lo\n",   poly0 );
  printf("  poly1(octal): 0%lo\n\n", poly1 );
  printf("This program generates two Gold sequences using "
	 "the above polynomials.\n"
	 "The seeds for the first  Gold sequence are '1' and '1'.\n"
	 "The seeds for the second Gold sequence are '1' and '5'.\n");
  printf("\n1st column: offset\n");
  printf("2nd column: autocorrelations of the first  Gold sequence\n");
  printf("3rd column: autocorrelations of the second Gold sequence\n");
  printf("4th column: cross-correlations between the two Gold sequences\n\n");

  pn_size = (1 << deg) -1;
  pn00 = gold_create( deg, poly0, poly1, 1, 1);
  pn01 = gold_create( deg, poly0, poly1, 1, 1);
  pn10 = gold_create( deg, poly0, poly1, 1, 5);
  pn11 = gold_create( deg, poly0, poly1, 1, 5);

  for ( offset = 0; offset < pn_size; offset++ ) { 
    int i;
    long acorr0, acorr1, xcorr;
    char c0, c1;

    acorr0 = acorr1 = xcorr = 0;
    for ( i=0; i < pn_size; i++ ) {
      acorr0 += ( (c0=gold(pn00)) == gold(pn01) ) ? +1 : -1;
      acorr1 += ( gold(pn10) == (c1=gold(pn11)) ) ? +1 : -1;
      xcorr  += ( c0 == c1 ) ? +1 : -1;
    }

    printf("%10d %10ld %10ld %10ld\n", offset, acorr0, acorr1, xcorr );

    // increment the offset.
    gold(pn01);
    gold(pn11);
  }
  puts("");

  gold_free(pn00);    gold_free(pn01);
  gold_free(pn10);    gold_free(pn11);

  return 0;
}