Carrier Frequency Synchronization and Tracking for OFDM Systems with Receive Antenna Diversity

Blind carrier frequency synchronization for orthogonal frequency division multiplexing (OFDM) systems with receive diversity is proposed in this paper. This method utilizes the fact that different receive branches contain uncorrelated observations about the same information bits. Due to receive diversity, our synchronizer can perform well without virtual subcarriers when channel state information (CSI) is known. In addition, we shall analyze the effects of CSI errors on the carrier frequency offset (CFO) estimation and show that the proposed algorithm is robust to CSI error. In particular, we derive the Cramer-Rao bound (CRB) from the mean square error (MSE) of the carrier frequency synchronizer. Computer simulation results show the performance improvement of our synchronizer to the single antenna systems and to the existing method.