[en] Using one-dimensional time-dependent diffusion equation, we have carried out a detailed analysis of modulated photon beam induced current experiment. We have used finite Fourier transformation method in our analysis. As we show, one can obtain the diffusion length, lifetime and diffusion constant of minority charge carriers simultaneously by measuring the amplitude and phase shift of carrier wave for different modulation frequencies. We feel that this method is quite convenient and will have advantages over other existing methods used to measure these parameters. (author)