Comparative study of four modified timing metrics for the frame synchronization in OFDMA mode of WMAN

In this paper, we adapt four existing timing metrics for frame synchronization in OFDMA mode of WMAN. Among the methods considered, first method uses cyclic prefix information present in the symbol, second method uses the symmetry in the time domain preamble data, third method exploits a priori knowledge of the preamble PN sequence, and the fourth method exploits the conjugate symmetry in the time domain preamble. It is shown that direct application of these timing metrics is not possible for frame synchronization of OFDMA mode of WMAN. Modifications to these timing metrics are presented to adapt them to OFDMA mode of WMAN. Simulations are conducted for AWGN and frequency selective channels to demonstrate the performance of the modified timing metrics.