freqd_to_timed.m

国外大学的同志作出来的好程序

function timed_symbols=freqd_to_timed(freqd_symbols, Nfft);
%
%block FFT transform
%
%
tx_num=size(freqd_symbols, 2);
OFDMsymbols_num=size(freqd_symbols, 1)/Nfft;
if OFDMsymbols_num~=floor(OFDMsymbols_num),
    disp('[freqd_to_timed]Error: not a integer number of OFDM symbols.');
    return;
end


%declaration of time domain signals
timed_symbols=zeros(size(freqd_symbols));


%IFFT for each antenna.
for ic_tx=1: tx_num,
    %resahpe for IFFT
    symbols_mat=reshape(freqd_symbols(:, ic_tx), Nfft, OFDMsymbols_num);
    %IFFT
    ifft_out = ifft(symbols_mat, Nfft);

    %make it a vector for each antenna
    timed_symbols(:, ic_tx)=ifft_out(:);
end