function out=blastdetect(H,Nt,r,M)
out=zeros(Nt,1);
constel=qammod(0:M-1, M);
L=1;K=[];
G=pinv(H);
Order=zeros(Nt,1);
%初始化檢測的層L

   for m=1:Nt
    K(m,1)=norm(G(m,:))^2;
   end
   [weight L]=min(K);
     
%循環
 for k=1:Nt
Order(k,1)=L;
w=G(L,:);
y=w*r;
[v p]=min(abs(y-constel));
a=constel(p);
out(L)=qamdemod(a,M);
r=r-H(:,L)*a;
H(:,L)=0;
G=pinv(H);

%select the next order
     for m=1:Nt
K(m,1)=norm(G(m,:))^2;
     end
       for d=1:k
     K(Order(d,1),1)=inf;
       end
  [weight_min L]=min(K);

 end