Frequency Synchronization in MIMO OFDM Systems

MIMO OFDM is a promising technique for the future wireless communications. However, the performance of MIMO OFDM systems is very sensitive to carrier frequency offset (CFO) which introduces inter-carrier-interference (ICI). Therefore, frequency synchronization is a critical problem in MIMO OFDM systems. In this paper, we study the problem of frequency synchronization in MIMO OFDM systems and propose a novel frequency synchronization scheme which uses training sequences composed of repeated pseudo-noise (PN) sequences for CFO estimation. Simulation results demonstrate that our scheme has very good performance, and is more robust and accurate than Schenk's scheme both in the AWGN channel and in the multipath channel.