detection.m

the signal detection in the MC-CDMA system

clear all;
close all;
clc
p=[1 0 0 1 0 1;1 1 0 1 1 1];
p=p(:,2:6);
init=[1 1 1 1 1];
state=kron(init,[1;1]);
c=[];
for i=1:31
    output=mod(sum(p.*state,2),2);
    state=[output state(:,1:4)];
    c=[c output];
end;
a=2*c(1,:).'-1;
b=2*c(2,:).'-1;
s=[];
for i=1:31
    b=[b(2:31);b(1)];
    s=[s a.*b];
end;
s1=s(:,3)./sqrt(31);
s2=s(:,4)./sqrt(31);
s3=s(:,5)./sqrt(31);
s4=s(:,6)./sqrt(31);
s5=s(:,7)./sqrt(31);
s6=s(:,8)./sqrt(31);
s7=s(:,9)./sqrt(31);
b1=rand(1,1000);
b2=rand(1,1000);
b3=rand(1,1000);
b4=rand(1,1000);
b5=rand(1,1000);
b6=rand(1,1000);
b7=rand(1,1000);

%----------定义6个用户数据
A1=1;
A2=1.4125;
A3=1.4125;
A4=1.4125;
A5=1.4125;
A6=1.4125;
A7=1.4125;
%---------各用户增益
c1=s1;
for i=1:1000
    if(b1(i)>0.5)
        b1(i)=1;
    else
        b1(i)=-1;
    end
end
r1=c1*b1;

c2=s2;
for i=1:1000
    if(b2(i)>=0.5)
        b2(i)=1;
    else
        b2(i)=-1;
    end
end
r2=c2*b2;

c3=s3;
for i=1:1000
    if(b3(i)>0.5)
        b3(i)=1;
    else
        b3(i)=-1;
    end
end
r3=c3*b3;

c4=s4;
for i=1:1000
    if(b4(i)>0.5)
        b4(i)=1;
    else
        b4(i)=-1;
    end
end
r4=c4*b4;

c5=s5;
for i=1:1000
    if(b5(i)>0.5)
        b5(i)=1;
    else
        b5(i)=-1;
    end
end
r5=c5*b5;



r=A1*r1+A2*r2+A3*r3+A4*r4+A5*r5;

SNR=20;
r=awgn(r,SNR);

%---------------------LCDPFCMA-------------------------

w=s1;
u=1*10^-3;
B=eye(31)-s1*s1';
x=zeros(31,1);
H=eye(31);
tic
for i=1:600
%     if mod(i,100)==0
%         i
%     end
    X=r(:,i);
    y(i)=w'*X;
    e=2*(y(i)^2-1)*y(i);
    g=e*B*X;
    if i==1                                             
        p=-H*g;
        R=eye(31);
    else
        j=x-x1;      
        k=g-g1;
        H=H-(H*j*j'*H)/(j'*H*j)+k*k'/(k'*k);
%         H=H-(H*k*k'*H)/(k'*H*k)+(j*j')/(k'*j);
%         H=H-(H*j*j'*H)/(j'*H*j)+k*k'/(k'*k)+(j'*H*j)*((k)/(k'*k)-(H*j)/(j'*H*j))'*((k)/(k'*k)-(H*j)/(j'*H*j));
%         H=H-(H*k*k'*H)/(k'*H*k)+(j*j')/(k'*j)+(k'*H*k)*((j)/(k'*j)-(H*k)/(k'*H*k))'*((j)/(k'*j)-(H*k)/(k'*H*k));
        p=-H*g;

    end
    g1=g;
    x1=x;


    x=x+u*p;
    w=s1+B*x;
    

        n=(A2*w'*s2)^2+(A3*w'*s3)^2+(A4*w'*s4)^2+(A5*w'*s5)^2+w'*0.01*w;
        SINR11(i)=((A1*w'*s1)^2)/n;

    





end
toc

%---------------------LSCMA-------------------------

w=s1;
R=eye(31);
tic
for i=1:600
%     if mod(i,100)==0
%         i
%     end


    X=r(:,i);
    y(i)=w'*X;
    d=y(i)./abs(y(i));
    e=y(i)-d;
    R=R+X*X';
    w=w-pinv(R)*X*e;

%     X=r;
%     y=w'*X;
%     d=y./abs(y);
%     e=y-d;
%     R=X*X';
%     w=pinv(R)*X*d';

    

        n=(A2*w'*s2)^2+(A3*w'*s3)^2+(A4*w'*s4)^2+(A5*w'*s5)^2+w'*0.01*w;
        SINR21(i)=((A1*w'*s1)^2)/n;


end
toc



%---------------------LCCMA-------------------------

w=s1;
u=1*10^-3;
B=eye(31)-s1*s1';
x=zeros(31,1); 
H=eye(31);
tic
for i=1:600
%     if mod(i,100)==0
%         i
%     end
    X=r(:,i);
    y(i)=w'*X;
    g=B'*(y(i)^2-1)*y(i)*X;
    x=x+u*g;
    w=s1-B*x;
    
    

        n=(A2*w'*s2)^2+(A3*w'*s3)^2+(A4*w'*s4)^2+(A5*w'*s5)^2+w'*0.01*w;
        SINR31(i)=((A1*w'*s1)^2)/n;


end
toc
i=1:10:600;
plot(0.00016917*i,10*log10(SINR11(i)),'k-');
hold on
i=1:70;
plot(0.00144250*i,10*log10(SINR21(i)),'k--');
i=1:10:600;
plot(0.00016500*i,10*log10(SINR31(i)),'k:');


legend('LCDFPCMA','LSCMA','LCCMA',4)
xlabel('迭代时间(S)');
ylabel('信号干扰噪声比SINR(dB)');
title('CMA多用户检测');