unquant.m

In this project we analyze and design the minimum mean-square error (MMSE) multiuser receiver for un

K=32;
N=64;
R=[1 2 3 4 5 6 7 8];
L=power(2,R);
a=eye(K);
z=[6 7 8 9 10 11 12 13 14 15 16 17];
snr=power(10,z/10);
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);
    end
end








 for i=1:12
   d=0;
   for q=1:(10^4)
       rd=randint(32,1);
       b=(2*rd-1);
       t=s*a*b;
       r1=awgn(t,z(i));
       r=alpha_a(i)*r1;
    
   
  
   R=((alpha_a(i))^2)*(s*a*a*s'+var(i)*eye(N,N));

   for c=1:32
   p=alpha_a(i)*s(1:N,c);
   w=inv(R)*p;
   
   m=w'*r;
   
   
   if m>0
       o(c)=1;
   else 
       o(c)=-1;
   end

   if o(c)~=b(c);
       d=d+1;
   end
   end
   q=q+1;
   end
   ber(i)=d/(32*10^4);
   ber1(i)=log10(ber(i));
 end
hold on
plot(z,ber1)