ldpc_linetime_encode_2.m

ldpc系统建模

function y=ldpc_linetime_encode_2(x,H,inv_phi1,g);
%tic
[m,n]=size(H);

A=H(1:m-g,1:n-m);B=H(1:m-g,n-m+1:n-m+g);
C=H(m-g+1:m,1:n-m);T=H(1:m-g,n-m+g+1:n);
E=H(m-g+1:m,n-m+g+1:n);

p2=sparse((m-g),1);

ax=mod(A*x',2);p1=mod(T\ax,2);
p1=mod(-E*p1,2);p1=mod(p1+mod(C*x',2),2);
p1=mod(-inv_phi1*p1,2);

bp1=mod(B*p1,2);     % bp is m-g_by_1
for i=1:(m-g)
    p2(i)=mod(ax(i)+bp1(i)+T(i,1:(i-1))*p2(1:(i-1)),2);
end;
    
y=[x,p1',p2'];

%toc