alam22sg.m

MIMO多天线收发 各种性能比较（BER曲线） 包括MMRC EGC SC Alamouti V-BLAST。信道为瑞利信道

function ber_22=alam22sg(snr2,Nr,p)

Nt=2;
Nr=Nr;
p=p;
no_bit_sym=1;

bits=10000;

%iter=0;
toterr=0;
% while toterr<soglia
%     iter=iter+1;
    
    for i=1:bits
        data=(2*round(rand(Nt,1))-1)/(sqrt(2));
        %Channel
        H=Cor_H(Nr,Nt,p);
        %AWGN
        sig=sqrt(0.5/(10^(snr2/10)));
        n=sig*(randn(Nr,Nt)+j*randn(Nr,Nt));
        
        X=[data(1) -conj(data(2));data(2) conj(data(1))];
        
        R=H*X+n;
        %Combiner
        s0=0;
        s1=0;
        for i=1:Nr
            s0=conj(H(i,1))*R(i,1)+H(i,2)*conj(R(i,2))+s0;
            s1=conj(H(i,2))*R(i,1)-H(i,1)*conj(R(i,2))+s1;
        end
        %Decoding
        if(real(s0)>0)
            Decoded1=1;
        else
            Decoded1=-1;
        end
        
        if(real(s1)>0)
            Decoded2=1;
        else
            Decoded2=-1;
        end
        decoded=[Decoded1 Decoded2];
         
%         dh=sqrt(2)*[1 -1]/2;
%         d11=((dh(1)-real(S(1)))^2+(imag(S(1)))^2);
%         d12=((dh(2)-real(S(1)))^2+(imag(S(1)))^2);
%         D1=[d11 d12];
%         
%         d21=((dh(1)-real(S(2)))^2+(imag(S(2)))^2);
%         d22=((dh(2)-real(S(2)))^2+(imag(S(2)))^2);
%         D2=[d21 d22];
%         %Decision
%         [scelta1,posizione1]=min(D1);
%         [scelta2,posizione2]=min(D2);
%         decoded=[dh(posizione1) dh(posizione2)];
        err_m1=sum(round(data')~=round(decoded));
        toterr=err_m1+toterr;
     end
    %end

ber_22=toterr/(bits*2)