% FIR channel
% this function is to generate the random channel Matrix
function channel = firChannel(m_transmitter, n_receiver, n_fir);


rand('state',0);
if n_fir > 0
    for index_trs = 1:m_transmitter
        for index_rcv = 1:n_receiver
            for index_fir = 1:n_fir + 1
                %channel_init(index_trs, index_rcv, index_fir) = 0.912 + 0.05 * randn(1,1);
                %awgn(power_var, SNR_dB)
                % 10^index_fir means that the h_mn(i)>=h_mn(j) while i=<j
                channel_init(index_trs, index_rcv, index_fir) = rand(1,1)*1.2/(10^(index_fir - 1));
            end;
        end;
    end;
else
    for index_trs = 1:m_transmitter
        for index_rcv = 1:n_receiver
            %channel_init(index_trs, index_rcv, index_fir) = 0.912 + 0.05 * randn(1,1);
            %awgn(power_var, SNR_dB)
            % 10^index_fir means that the h_mn(i)>=h_mn(j) while i=<j
            channel_init(index_trs, index_rcv) = awgn(1,10);
        end;
    end;  
end;


channel = channel_init;

%   to get every fir channel of h(n,m) 
%   h(n,m) is row vector of (1 * L_fir), L_fir <= L+1