Robust High Resolution Time of Arrival Estimation for Indoor WLAN Ranging

This paper proposes a novel robust high resolution time of arrival (TOA) estimation method for IEEE 802.11g/n range estimation in indoor environments. The algorithm identifies the TOA of ranging symbols by means of baseband signal processing using a single 802.11 channel. A subsample signal model provides high timing resolution. The CLEAN deconvolution algorithm, coupled with a parameter optimization step, provides robustness to multipath. Two ranging symbols are investigated: the 802.11 standard long training sequence and an impulsive symbol. In real-world wireless line of sight experiments, at ranges of up to 25 m, the method when applied to impulsive symbols was found to provide median ranging errors of 0.34 and 0.93 m with directional and omnidirectional antennas, respectively.