m6.asv

硕士CDMA作业

%6阶m序列 1+x+x^6%
a=zeros(63,7)
b=zeros(7,1)
c=zeros(1,63)
b=[0 0 0 0 0 1 0]
a(1,6)=1
for i=2:63,
    temp=b(1,7);
    b(1,7)=b(1,6);
    b(1,6)=b(1,5);
    b(1,5)=b(1,4);
    b(1,4)=b(1,3);
    b(1,3)=b(1,2);
    b(1,2)=b(1,1);
    b(1,1)=xor(b(1,1),temp);
    for j=1:7,
        a(i,j)=b(1,j);
    end
end
for k=1:63,
    if (a(k,7)==0),
        c(1,k)=-1;
    else
        c(1,k)=a(k,7); 
    end
end
s=0
for t=-200:200
    for n=1:6300,
        s=s+c(1,n)*c(1,mod((n+t),63));
    end  
    s=s/6300
    plot(t,s)
    hold on
 end