Sampling Frequency Offset Estimation for MIMO OFDM Systems

This paper proposes a pilot-assisted sampling frequency offset (SFO) estimation algorithm for MIMO OFDM (multiple-input multiple-output orthogonal frequency division multiplexing) systems. The sampling frequency offset is estimated from phase errors in the received pilot subcarrier symbols between two transmitted OFDM blocks. The optimal weight for each SFO estimate is derived. The proposed weighted method is remarkably superior to the unweighted method, and the receive diversity exploited by the proposed method can significantly reduce the MSE (mean square error) of the SFO estimator. Simulation results show that the proposed algorithm can accurately estimate the SFO in both AWGN channels and multipath fading channels.