The block diagram of an OFDM modulator/demodulator
In order to make an OFDM system practical, a more economical implementation of the modulator and demodulator is required, since according to Figure 1.1 and Figure 1.2 a large number of identical modulator/demodulator blocks would be needed. This can be accomplished through discrete time signal processing and by making use of the filtering properties of the discrete Fourier transform (DFT).