function y=ldpc_linetime_encode(x,H,inv_phi1,g);
%WITH THE PARAMETER PROCEDUARE WE CAN GET H,inv_phi1,GAP;
%H IS PARITY CHECK MATRIX,g IS GAP BETWEEN H AND REAL DOWNDIAGNAL 
%MATRIX DISTANCE,INV_PHI1 SHOULD BE INVERTIBLE;
%x IS A INPUT MESSAGE BIT VECTOR,y IS A OUTPUT CODEWORD;
%rand('state',123);
%tic
[m,n]=size(H);
%x=(sign(rand(1,n-m)-0.5)+1)/2;
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);
p1=mod(A*x',2);p1=mod(inv(T)*p1,2);
p1=mod(-inv_phi1*(-E*p1+C*x'),2);
p2=mod(A*x'+B*p1,2);
p2=mod(-inv(T)*p2,2);y=[x,p1',p2'];%CHECK COMMAND:sparse(mod(H*y',2))
%toc