channel_est.m

some code in mimo ofdm

%Channel Estimation
%
%
%****************************************
function [chan_coeff_est,h_est] = channel_est(data,TS_vector,numcarr,Nr,Nt,Num_Path)

   
%tao ma tran duong cheo kenh F(LNum_RxAnt)
for i=1:numcarr
    for l=1:Num_Path
        F(i,l)=exp(-j*2*pi*(l-1)*(i-1)/numcarr);
    end
end
I_matrix=eye(Nr,Nr);
Fl=kron(I_matrix,F);


%tao ma tran tin hieu pilot duong cheo
Sp=[];
for TxAnt=1:Nt
    temp=diag(TS_vector(TxAnt,:));
    Sp_diag=kron(I_matrix,temp)*Fl;
    Sp=[Sp,Sp_diag];
    clear temp Sp_diag;
end

W=inv(Sp'*Sp)*Sp';
hh=W*data;
chan_coeff_est=hh;
chan_coeff=reshape(hh,Num_Path*Nt,Nr);
h_vector=[];
for RxAnt=1:Nr
    h_row=[];
    for TxAnt=1:Nt
        h=chan_coeff((TxAnt-1)*Num_Path+1:TxAnt*Num_Path,RxAnt);
        h_row=[h_row,h];
        clear h;
    end
    h_vector=[h_vector;h_row];
    clear h_row;
end
h_est=h_vector;
clear Sp W hh chan_coeff h_vector;