A Study of Iterative Joint Synchronization for Time Offset and Frequency Offset in IEEE802.16d WirelessMAN OFDM System

This paper is a study of an iterative joint algorithm for frequency offset and time offset synchronizations used in 256 orthogonal frequency division multiplexing of IEEE 802.16d wireless-MAN system. As deployed in an urban area and targeted at providing a high data rate transmission, IEEE 802.16d system requires a robust synchronization mechanism to guarantee the transmission reliability. A time-domain preamble structure is provided in IEEE 802.16d standard to detect and correct the synchronization errors along time and frequency dimensions. Our research focus on the study of an iterative joint algorithm for time offset and frequency offset synchronization based on the preamble. And we simulate this algorithm based on a framed wireless-MAN 256 OFDM downlink physical layer simulation link to investigate its performance. The simulation results show that this algorithm could reduce the probability of synchronization failure below 10^-4 when E_s/N₀ is larger than 14 dB, and that it is not sensitive to channel spread delay and moving speed in a fixed broadband wireless environment. Finally, two transmission rates are simulated with this algorithm to show its application effectiveness