Timing Synchronisation for OFDM-WLANs with Time Averaging Scheme

The IEEE 802.11 wireless local area network (WLAN) standard is based on random access, such that the receiver does not know exactly when a packet starts. The conventional maximum likelihood (ML) method to packet detection and time synchronisation is based on the auto and cross correlation functions. Its performance suffers from multipath channel fading in low SNR scenarios. In this paper a robust synchronisation scheme exploits the time averaging technique based only on the short training sequence (STS). The paper also investigates the effect of cyclic delay diversity (CDD) introduced by multiple antenna transmission and presents a comparison with the maximum likelihood (ML) method to time synchronisation