x=0:351
for i=1:352
 if x(i)<=31
                y(i)=1-x(i)/31;
 elseif (x(i)<=126)&(x(i)>=32)
                y(i)=[rand(1)-0.5]*0.1;
 elseif (x(i)<=159)&(x(i)>=127)
                y(i)=(x(i)-127)/32;
 elseif (x(i)<=191)&(x(i)>=160)
                y(i)=1-(x(i)-160)/32;
 elseif (x(i)<=287)&(x(i)>=192)
                y(i)=[rand(1)-0.5]*0.1;
 elseif (x(i)<=319)&(x(i)>=288)
                y(i)=(x(i)-287)/32;
 elseif (x(i)<=351)&(x(i)>=320)
                y(i)=1-(x(i)-320)/32;
         else 
               y(i)=[rand(1)-0.5]*0.1;
 end
end
y(158)=y(158)-0.0313;
y(159)=y(159)-0.0625;
y(160)=y(160)-0.0313;
y(286)=y(286)-0.0313;
y(287)=y(287)-0.0625;
y(288)=y(288)-0.0313;
y=y*0.85+[rand(1,352)-0.5]*0.1;
plot(x,y)
axis([0 351 -0.5  1.2]);
xlabel('采樣點');
ylabel('循環前綴的相關值')
title('高斯白噪下的循環前綴相關特性')