Doppler and/or beyond-GI multipath compensation by using an antenna array for OFDM receiver (Poster)

The Pre-FFT minimum mean square error (MMSE) antenna array (AA) can depress the large delay paths signal in multi-path fading channel by performing the spatial filtering to desired/undesired signals in time domain. For mobile OFDM application, the conventional AA scheme cannot render the system less sensitive to Doppler effects. In this paper, an AA scheme is derived to suppress both Doppler shift and/or greater than guard interval (GI) delay multipath without any increasing of computations by comparing with the conventional one. Based on this, a follow-up sample-based phase rotations compensating unit was jointed with the AA output to depress the effects of Doppler. The proposed receiver does not require much more compute cost. Simulation studies show, that the proposed AA approach can outperform the conventional carrier diversity (CD) and AA receivers, especially while they suffer the conditions of large Doppler shift and long delay spread.