Application of angular diversity in OFDM systems

Orthogonal frequency division multiplexing (OFDM) can be successfully used in mitigating the effect of multipath in a wireless channel. However, its´ performance degrade in the presence of Doppler spreading. In this paper, multiple beamforming using uniform linear arrays (ULA) is used for OFDM systems to reduce Doppler spread and exploit the advantage of diversity. Each of the beams receiver signal which equal Doppler spread, which are combined using equal gain combining (EGC). We also present a method of determining the frequency compensating parameters, for beams pointing in different directions. Finally, our simulation results show that angular diversity in OFDM systems can provide significant improvement as compared to using only single beamforming.