Fractional Fourier Transform OFDM system performance enhancement over doubly dispersive channels

Abstract

The fractional Fourier transform (FrFT) has been suggested to improve the performance of the OFDM over doubly dispersive channels that cannot be achieved with traditional OFDM even with complex equalizers. In this paper the performance of OFDM based FrFT is studied with multiple fractional orders at different Doppler shift. Simulation results demonstrate processing improvement due to using FrFT instead of Fourier Transform (FT) in OFDM system. The same bit error rate (BER) is achieved without increasing the transmitting signal to noise ratio (SNR) and processing improvements are gained up to 3 dB for different Doppler frequencies.