dft_estimate.m

OFDM系统的仿真代码MATLAB环境下

function data_cir = dft_estimate(pilot_freq_cir)
% pilot_freq_cir: cir at the pilot frequency
% channel_cir: cir at all the frequency

global sim_consts;

N1 = sim_consts.NumPilotSubc; % the length of the window should be the same as the number of pilot per ofdm symbol
N2 = 64;


for i = 1:size(pilot_freq_cir,2) 
    window_pilot_freq_cir = pilot_freq_cir(:,i);
    window_pilot_time_cir = ifft(window_pilot_freq_cir);
    window_subchan_time_cir = [window_pilot_time_cir;zeros(N2-sim_consts.NumPilotSubc,1)];    
    window_subchan_freq_cir = fft(window_subchan_time_cir);
    subchan_freq_cir(:,i) = window_subchan_freq_cir;
end
 
data_cir = subchan_freq_cir(sim_consts.DataSubcIdx,:);