www.gusucode.com > OFDM_16QAM系统仿真源码程序 > OFDM_16QAM系统仿真源码程序/code/ry_time_to_fre.m
function [fre_sym,pilot_sym] = ry_time_to_fre(time_sig, N_SPF,channel_time) % Convert the time signal to frequency symbols by FFT, Channel equalization and extract pilot symbols OFDM_sig = reshape(time_sig, 64+16,N_SPF); % Reshape the received time signal to OFDM symbols,64 is FFT length,16 length of cyclic prefix OFDM_sig = OFDM_sig(17:64+16,:); % Remove the cyclic prefix OFDM_sig = OFDM_sig.'; channel_fre = fft(channel_time,64); % Channel estimation % channel_fre = channel_fre'; for m = 1:N_SPF temp_sig = OFDM_sig(m,:); % Received time signal of the mth OFDM symbol temp_sym = fft(temp_sig)/sqrt(64); % FFT to convert the time signal to frequency symbols temp_sym = temp_sym./channel_fre; % Channel equalization % Extract the information symbols and pilot symbols % fre_sym(m,:) = [temp_sym(39:43),temp_sym(45:57),temp_sym(59:64),temp_sym(2:7),temp_sym(9:21),temp_sym(23:27)]; pilot_sym(m,:) = [temp_sym(44),temp_sym(58),temp_sym(8),temp_sym(22)]; end fre_sym = fre_sym.'; fre_sym = fre_sym(:).'; % Parallel to serial conversion