N=64;K=32;z=[6 7 8 9 10 11 12 13 14 15 16 17];snr=power(10,z/10);R=[1 2 3 4 5 6 7 8];L=power(2,R);a=eye(K);var=power(10,-z/10);alpha_a=power((K/N+var),-0.5);delta=[1.5956,0.9957,.5860,0.3352,0.1881,0.1041,0.0569,0.0308];for i=1:N    for j=1:K        r=randint;        s(i,j)=(2*r-1)/sqrt(N);    endendfor i=1:12     c=s(1:N,5);     R=((alpha_a(i))^2)*(s*a*a*s'+var(i)*eye(N,N));    p=alpha_a(i)*c;    u(i)=p'*inv(R)*p;    gamma(i)=u(i)/(1-u(i));    ber(i)=qfunc(sqrt(gamma(i)));    end     ber1= log10(ber(1:12));       plot(z,ber1,'r')