gold.c

在linux系统下开发研究移动通信的工具型代码

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

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

#include "gold.h"

/*
 * It creates a Gold code generator with the two preferred m-sequences
 * with the given seeds. The Gold code generator is returned.
 */
Gold * gold_create( unsigned deg, unsigned long p0, unsigned long p1,
		    unsigned long s0, unsigned long s1 )
{
  Gold *gold;

  if ( deg > 31 ) {
    fprintf(stderr, "gold_create: ..cannot handle deg > 31\n");
    return NULL; 
  }

  gold = (Gold*) malloc ( sizeof(Gold) );
  gold->mseq0 = mseq_create( deg, p0, s0 );
  gold->mseq1 = mseq_create( deg, p1, s1 );

  return gold;
}

/* gold_free() deallocates the memory space for the Gold sequence generator. */
void gold_free( Gold *gold )
{
  mseq_free( gold->mseq0 );
  mseq_free( gold->mseq1 );
  free( gold );
}

/* gold() gives the next Gold sequence. The sequence is unipolar, ie 1 or 0. */
char gold( Gold *gen )
{
  return mseq(gen->mseq0) ^ mseq(gen->mseq1);
}