Synchronization in Interleaved OFDMA Systems

tiple Access (OFDMA) as a new multiple access technology has received a lot of attention. Multi-carrier communica-tions increase the efficiency and capacity of wireless net-works, but are very sensitive to carrier frequency synchro-nization errors. The estimation of carrier frequency offset in the uplink of OFDMA system is extremely challenging due to the nature of multiple-parameter estimation, especially in an interleaved carrier assignment scheme. In this paper, the base station receiver signal structure are investigated and a structure based estimator is proposed for simultane-ously estimating multiple users ’ carrier frequency offsets. The estimator presented here exploits the inner structure of the OFDMA signal block in the uplink and doesn’t need the presence of training symbols or pilot tones. I