Timing synchronization for OFDM based spectrum sharing system

Spectrum sharing is promising to improve the efficiency of spectrum usage. However, this technology may incur severe narrow band interference (NBI), which seriously complicates the synchronization problem. This paper investigates the timing synchronization problem in the presence of NBI for the OFDM-based spectrum sharing systems. We consider the cross-correlation based timing synchronization and propose a pre-filter to mitigate the NBI effect. Based on the theoretical analysis of miss detection and false alarm probabilities of the cross-correlation based synchronization algorithm, the pre-filter parameters can be devised by exploiting the stationary property of the NBI and the additive thermal noise. The simulation results have shown that this pre-filter effectively eliminates the NBI effect and enables the cross-correlation based algorithm to achieve the performance of the system without NBI.