A Pre-FFT OFDM adaptive antenna array with eigenvector combining

Abstract-This paper proposes a novel pre-FFT type OFDM adaptive array antenna called "Eigenvector Combining." The eigenvector combining is a realization of a post-FFT type OFDM adaptive array antenna through a pre-FFT signal processing, so it can achieve excellent performance with less computational complexity and shorter training symbols. Numerical results demonstrate that the proposed eigenvector combining shows excellent bit error rate performance close to the lower bound just with two training symbols. I. INTRODUCTION Orthogonal frequency division multiplexing (OFDM), which is a pre-distortion or an equalization technique at transmit side in a sense, is an efficient technique for high-speed digital transmission over severe multipath fading channels To maintain high-speed reliable wireless communications systems, the use of multiple antennas at receive side has been considered as an effective tool not only for gain enhancement, increased spectral efficiency[3] but also for interference suppressio