A pre-FFT OFDM adaptive antenna array based on beam-space channel estimation

The adaptive antenna array used in OFDM systems has been an interesting topic in recent years. A modified pre-FFT antenna array scheme is proposed, in which the beam-space channel state information (CSI) estimation is adopted. A uniform linear antenna array is considered. It is confirmed by simulations that the proposed scheme performs much better than the element-space one, especially when strong interference is present. In the element-space scheme, CSI estimation is made on the array elements, which is not robust and is likely to fail under strong interference.