% 最優天線選擇算法
function coptimal105=optimal105(p)
  % p  信噪比
nr=10;
nt=10;
s=0;
A=zeros(5,252);
for i1=1:6
    for i2=i1+1:7
        for i3=i2+1:8
            for i4=i3+1:9
                for i5=i4+1:10
                    s=s+1;
                    A(:,s)=[i1 i2 i3 i4 i5]';
                end
            end
        end
    end
end

     h3=randn(nr,nt);
C3=zeros(1,252);
for j=1:252
    C3(j)=log2(det(eye(nt)+(p/nt)*h3(A(:,j),:)'*h3(A(:,j),:)));
end

coptimal105=max(C3);