cdma3.m

硕士CDMA作业

%Rake接收机%
clear all
%function zuoye2
r=[0,0,0,0,0,1];
c=zeros(63,6);
c1=zeros(63,6);
c(1,:)=r;
c1(1,:)=r;
for i=2:63
    c(i,2:6)=c(i-1,1:5);
    c(i,1)=mod((c(i-1,1)+c(i-1,6)),2);
    c1(i,2:6)=c1(i-1,1:5);
    c1(i,1)=mod((c(i-1,1)+c(i-1,2)+c(i-1,5)+c(i-1,6)),2);
end
for i=1:63
    for j=1:6
        c(i,j)=(-1)^(c(i,j));%把0,1变成1.-1
        c1(i,j)=(-1)^(c1(i,j));
    end
end

l=25;
for t=1:l
d=100;
b1=randsn(d);
b2=randsn(d);
s1=zeros(1,1);
s2=zeros(1,1);
for m=1:d
        r1=c(:,1)*b1(1,m);
        r2=c1(:,1)*b2(1,m);
        s1=[s1;r1];
        s2=[s2;r2];
end
s1=s1(2:63*d+1,1);
s2=s2(2:63*d+1,1);
Noi11=normrnd(0,t,63*d,1);
Noi12=normrnd(0,t,63*d,1);
Noi21=normrnd(0,t,63*d,1);
Noi22=normrnd(0,t,63*d,1);
s11=s1+Noi11;
s12=s1+Noi12;
s21=s2+Noi21;
s22=s2+Noi22;
s=zeros(63*d+3,1);
s(1,1)=s11(1,1);
s(2,1)=s11(2,1)+s12(1,1);
s(3,1)=s11(3,1)+s12(2,1)+s21(1,1);
s(4,1)=s11(4,1)+s12(3,1)+s21(2,1)+s22(1,1);
for i=5:63*d
    s(i,1)=s11(i,1)+s12(i-1,1)+s21(i-2,1)+s22(i-3,1);
end
s(63*d+1,1)=s12(63*d,1)+s21(63*d-1,1)+s22(63*d-2,1);
s(63*d+2,1)=s21(63*d,1)+s22(63*d-1,1);
s(63*d+3,1)=s22(63*d,1);
%取第一、二路第一个信号
for i=1:d
    for j=1:63
        y1((i-1)*63+j,1)=s((i-1)*63+j,1)*c(j,1);
        y2((i-1)*63+j,1)=s((i-1)*63+j+2,1)*c1(j,1);
    end
end
%9被换成了*号
x19=zeros(d,1);
x29=zeros(d,1);
for i=1:d
    for j=1:63
        x19(i,1)=x19(i,1)+y1((i-1)*63+j,1);
        x29(i,1)=x29(i,1)+y2((i-1)*63+j,1);
    end
    x19(i,1)=sign(x19(i,1));
    x29(i,1)=sign(x29(i,1));
end
z1=b1'-x19;
z2=b2'-x29;
z19=0;
z29=0;
for i=1:d
    z19=z19+z1(i,1)^2;
    z29=z29+z2(i,1)^2;
end
z199(t,1)=z19/(4*d);
z299(t,1)=z29/(4*d);
end
figure(1)
%plot(z199);
L=zeros(l,1);
for i=1:l
    L(i,1)=1/i;
end
semilogy(z199,L,'-r*');
grid on;
hold on
semilogy(z299,L,'-gd');
hold off
title('Rake接收')
xlabel('SINR')
ylabel('误码率')
legend('user1','user2')