thp_encoder.m

encoder and decoder programme for pre-coding MIMO system based on THP algorithm

function output_data = THP_encoder(input_data,H,M)


mod_num = 2 * sqrt(M);
[Tx,T] = size(input_data);
Rx = length(H(:,1));

a_Tx = input_data;

for t = 1:T
    ChM = H(:,Tx*(t-1)+1:Tx*t);
    S = chol(ChM' * ChM);
    for i=1:Tx
        Temp(i)=inv(S(i,i));
    end
    G = diag(Temp);
    F = inv(S') * ChM';
    B = G * S;
    
    x(Tx,t) = a_Tx(Tx,t);
    
    for i=Tx-1:-1:1
        x_eval = a_Tx(i,t) - B(i,i+1:Tx) * x(i+1:Tx,t);
        x(i,t) = (mod(real(x_eval)+mod_num/2, mod_num) - mod_num/2)...
                + j * (mod(imag(x_eval)+mod_num/2, mod_num) - mod_num/2);
    end
end

output_data = x;