Bayesian frame synchronization for 802.11a WLANs: experimental results

Frame and frequency synchronization schemes are critical in the design of OFDM receivers because misalignment in time and/or frequency can lead to loss of orthogonality and ultimately to packet loss. In burst communications, such as IEEE 802.11a WLANs, synchronization must be achieved at the beginning of the packet using only the given preamble. Thus, for such systems it is important to design accurate synchronization methods that converge quickly. A new method based on a Bayesian changepoint detection approach was recently demonstrated to be an effective solution but was accomplished using simulated data. In this paper, experimental results using data collected in a WLAN testbed are presented. These results help confirm the conclusion that the Bayesian approach has advantages over some existing synchronization methods in terms of latency, complexity and accuracy. Other advantages of the Bayesian approach are that it does not require determination of a threshold for detection and that it can be implemented recursively to facilitate online calculation