Provided by: International Journal of Electronics and Computer Science Engineering
Traditional Fast Fourier Transform algorithm makes the implementation of the multicarrier system feasible and attractive with respect to single-carrier systems. However, when the channel is doubly selective (i.e. time-frequency selective), this traditional methodology fails. Since the channel frequency response is rapidly time-varying as a result the optimal transmission/reception methodology not able to process non-stationary signals. The non-stationary approach can be approximated using signal bases that are especially suited for the analysis/synthesis of non-stationary signals. Using FRFT-OFDM (FRactional Fourier Transform based Orthogonal Frequency Division Multiplexing) systems the BER Vs SNR performance is evaluated that employs signal bases of the chirp type that in practice corresponds to the Fractional Fourier Transform signal bases.