paixu.m

降低OFDM系统PAPR的PTS改进算法——相位因子估计。出CCDF比较图

%相位因子估计法
clear;
v=8;
nl=100;
for n=1:nl;
    a=rand(1,256)>0.5;
    C=(a*2-1)/sqrt(2);
    sreal=C(1:2:256);
    simage=C(2:2:256);
    D=sreal+j.*simage; 
    
    % oversample 4
     z1=[D(1:128/2),zeros(1,3*128),D(128/2+1:128)];
     l1=length(z1);
     % divided into v sets 
      
     x4=zeros(1,512);
     P=zeros(l1,v);
     P1=zeros(l1,v);
     Q=zeros(l1,v);
     for k=1:v
         z(k,:)=[zeros(1,(k-1)*128/v),D((k-1)*128/v+1:k*128/v),zeros(1,(l1-(k-1)*128/v-128/v))];
         iz(k,:)=ifft(z(k,:));  
         iz(k,:)=iz(k,:)*512;
         P(:,k)=iz(k,:);
     end
     for i1=1:l1
         x3=abs(P(i1,:)).^2;
         P1(i1,:)=x3;
     end
     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     for i1=1:l1
         number=paixu1(P1(i1,:));
         for m=1:v
             R(:,m)=P1(:,number(2,m));
         end
     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%               
         for i2=1:l1;
             Q1(i2,:)=R(i2,1:2:v);
             Q2(i2,:)=R(i2,2:2:v);
             Q2(i2,:)=-1*Q2(i2,:);
         end
         x1=sum(Q1');
         x2=sum(Q2');
         x3=x1+x2;
         v1=max(abs(x3));
         m1=mean(abs(x3));
         papr1=10*log10(v1/m1);
         x4(i1)=papr1;
     end
     papr2(n)=min(x4);
     papr2(n)=papr2(n)+3;
 end
 ccdf0=zeros(1,131);
 NN=0:.1:13;
   for n=1:nl;
       for l=1:131;
           if papr2(n)>NN(l);
              ccdf0(l)=ccdf0(l)+1;
          end     
       end
   end
   ccdf1=ccdf0./100;
   figure(1)
   semilogy(NN,ccdf1,'r')
   title('CCDF曲线比较')
   xlabel('papr( in dB)'),ylabel('ccdf')
   legend('相位因子估计算法');
   grid on