test9.cpp

软判决功率归一viterbi约束长度9

/*
*                          viterbi译码9约束长度软判决 功率归一化
************************************************************************************************
* MODULE NAME:  test9.cpp  
*************************************************************************************************
* DESCRIPTION     :BER测试程序
*
* FUNCTIONS       :信息位编码，加白噪声，译码，测BER 
*                                                   
*************************************************************************************************
*/
#include <iomanip>
#include "decode.h"
#include "pn_seq.h"
#include "channel.h"
void main()
{   int i,j;
    double power=0;
    int  error_count=0;    //译码后错误信息比特
    int  trans_error=0;    //译码前传输错误码元
	int  error_frame=0;    //错误帧
    int num;               //记录结束个数
    bool error=false;     //记录当前帧是否错误
    unsigned a[192];  //信源信息帧
    double channel_trans1[192]; //信道经噪声污染的已编码帧
    double channel_trans2[192];
    int b1_polar[192];   //已编码帧加极性
	int b2_polar[192];
    unsigned b1_receiv[192]; //接受后已01判决的码元
	unsigned b2_receiv[192];
	l=184;	m=8; //信息位长度184 归零位长度8
    int bit_num; //量化比特数

cout<<"量化比特数:";
cin>>bit_num;
bit_num=pow(2,(bit_num-1));

AWGN p,*pi;
cout<<"信噪比:";
cin>>p.snr;
cout<<"跳出次数:";
cin>>num;

p.rate=0.5;   //设置白噪声
p.reset=1;
p.ix=1;
p.iy=1;
p.iz=1;
p.I_sigma=2*(p.rate)*(pow(10.0,(p.snr)/10));;
p.sigma=sqrt(1/p.I_sigma);
pi=&p;

  PN_seq(a,l,true); //伪随机序列生成信息位
  for (i=l;i<l+m;i++) //加归零位
	 a[i]=0;

   conv_encode_m9(a,l+m); //编码
   init_trans();//建立状态网格图

    
  for ( i=0;i<l+m;i++)   //编码加极性
	{    

		if (b1[i]==1) b1_polar[i]=1;
		              else b1_polar[i]=-1;
        if (b2[i]==1) b2_polar[i]=1;
		              else b2_polar[i]=-1;
	}

    j=0;//测试帧个数
	error_count=0;
    trans_error=0;
    error_frame=0;

while	((error_count<num)&&(j<25000))
{  j++;
    
  //加信道噪声
 awgn_channel(b1_polar , channel_trans1 ,pi,l+m);
 awgn_channel(b2_polar , channel_trans2 ,pi,l+m);
 
 //对接受码元第1位功率归一
     power=0;    //求序列功率
    for ( i=0;i<l+m;i++) 
	{
	 power=power+channel_trans1[i]*channel_trans1[i];
	
	}
	power=sqrt(power/192);            //量化
    for ( i=0;i<l+m;i++)  
    {if (channel_trans1[i]>=0)
		     receiv1[i]=floor((bit_num-1)*channel_trans1[i]/power);
	    else receiv1[i]=ceil((bit_num-1)*channel_trans1[i]/power);
	
	 if (receiv1[i]>bit_num)          receiv1[i]=bit_num;
     if (receiv1[i]<(bit_num*(-1)+1)) receiv1[i]=bit_num*(-1)+1;	
	}
	

 //对接受码元第2位功率归一
       power=0;
    for ( i=0;i<l+m;i++)            //求序列功率
	{
	 power=power+channel_trans2[i]*channel_trans2[i];
	 
	}
	power=sqrt(power/192);              //量化
    for ( i=0;i<l+m;i++)  
    {if (channel_trans1[i]>=0)
		     receiv2[i]=floor((bit_num-1)*channel_trans2[i]/power);
	    else receiv2[i]=ceil((bit_num-1)*channel_trans2[i]/power);
	 if (receiv2[i]>bit_num)          receiv2[i]=bit_num;
     if (receiv2[i]<(bit_num*(-1)+1)) receiv2[i]=bit_num*(-1)+1;

	}

 search();    //译码

 for ( i=0;i<m+l;i++)
 {    
	   if (channel_trans1[i]>0)  b1_receiv[i]=1;
	                    else b1_receiv[i]=0;
       if (channel_trans2[i]>0) b2_receiv[i]=1;
	                    else b2_receiv[i]=0;
   }


 for (i=0;i<l+m;i++) //统计接收错误
 {    
	 if (b1[i]!=b1_receiv[i]) {trans_error++;}
	 if (b2[i]!=b2_receiv[i]) {trans_error++;}
  }
  
 
   
    error=false;
   for (i=0;i<l+m;i++)  //统计译码错误
   if (a[i]!=result[i])
   {      error=true;  
	      error_count++;
	      cout<<setw(5)<<error_count; 
	  };    
  if (error)error_frame++; //统计误帧

} 
cout<<"总帧数:"<<j<<endl;	
cout<<"错误比特:"<<error_count<<"BER:"<<(double)(error_count)/(192*j)<<endl;
cout<<"传输错误码元:"<<trans_error<<"误码元率:"<<(double)(trans_error)/(192*j*2)<<endl; 
cout<<"传输错误帧:"<<error_frame<<"误帧率:"<<(double)error_frame/j<<endl; 
}