Matched Filter Based Timing and Frequency Synchronization for Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing Systems

In this paper, a novel matched filter based timing and frequency synchronization method for multiple input multiple output orthogonal frequency division multiplexing (OFDM) systems is presented. Using a unique training symbol structure, matched filter based timing synchronization is employed for estimating the timing location at multiple receiver antennas. This training symbol based coarse timing synchronization at the receiver using the proposed method ensures remarkable performance improvement in SUI channels, as compared to previous timing synchronization schemes. Multiple training symbols, simultaneously transmitted from multiple antennas and received at multiple antennas, are utilized for coarse timing synchronization and channel estimation. Based on channel estimates, channel equalization is performed on the received data streams for stream separation and interference cancellation. For significant performance improvement in highly dispersive channels, the separated streams can further undergo fine timing synchronization to estimate the exact position of received OFDM symbols. Using MATLAB based computer simulations, bit error rate performance is investigated under SUI channels to highlight an improved performance achieved through the proposed synchronization method. Moreover, carrier frequency offset estimation and compensation is incorporated in proposed scheme to ensure its robustness in cases where carrier frequency synchronization is inevitable, in addition to timing synchronization.