Preamble-based timing synchronization for OFDM systems

In this paper data aided (DA) timing synchronization scheme for orthogonal frequency division multiplexing (OFDM) system is proposed. It works in time domain and the timing metric is independent of the specific structure of the preamble. Quadrature phase shift keying (QPSK) signals, independent Rayleigh fading multi path channel in presence of additive white Gaussian noise (AWGN) are considered. The proposed algorithm estimates the starting point of OFDM frames by using matched filter (MF) at the receiver end. The performance is evaluated and compared in terms of probability of erasure (PE) or probability of not detecting a frame and mean squared error (MSE) with the existing timing synchronization methods for OFDM systems. The simulation results indicate that the proposed method improves the performance of the system significantly. Also the computational time for timing synchronization is less as compared to previously existing methods.