text2.c

本程序可实现对于信源的BPSK调制

 #include <stdlib.h> 
 #include <iostream.h> 
 #include <conio.h> 
 #include <time.h> 
 #include <stdio.h>
 #include <math.h>


double uniform(double a,double b)
{double m,n;
m=b-a;
srand((unsigned)time(NULL));
n=a+(double)(m*rand()/(RAND_MAX+1.0));
return n;}//随机数

double  Gauss(double m,double s)   
    {   
    double  n=0,gaussway; 
	int i;
	srand((unsigned)time(NULL)); 
    for(i=0;i<12;i++)   
    {  
	  n+=(double)rand()/RAND_MAX;   
    }   
    n=n-6; //标准化 
	gaussway=m+sqrt(s)*n;
    return gaussway;   
    }  //高斯信号
 void BPSK(int signal[50],double bsignal[50])
 { int i;
	 for(i=0;i<50;i++)
	{if (signal[i]==0)
	    bsignal[i]=-1;
	else bsignal[i]=1;
	}
}//调制

main()
{int ssignal[50];double bbsignal[50];double siggas[50];
int i;
double uniform(double a,double b);
double  Gauss(double m,double s);
void BPSK(int signal[50],double bsignal[50]);
for(i=0;i<50;i++)
{if(uniform(0,1)<=0.5)
ssignal[i]=0;
else ssignal[i]=1;
}
BPSK(ssignal,bbsignal);
for (i=0;i<50;i++)
       siggas[i]=bbsignal[i]+Gauss(0,0.01);
 FILE *p;
p=fopen("a.txt","w+");
 for(i=0; i<50; i++)
 {
  fprintf(p ,"%1.3f\t", siggas[i]);
 }//保存到文件a.txt中
 fclose(p);
}