Time of arrival estimation for range-based localization in UWB sensor networks

Accurate Localization has gained significant interest within sensor networks recently and positioning systems based on Ultra-Wideband (UWB) technology have been considered, because the UWB signals have a very good accuracy due to the high time resolution (large bandwidth). Time of Arrival (TOA) estimation of the first path is usually used for range-based localization in realistic environments within UWB sensor networks, which can be challenging in dense multipath environments. In this paper, TOA algorithms for range-based localization in UWB sensor networks are analyzed and two new TOA estimation methods are proposed. One is the constant false alarm rate (CFAR) method, which is based on the CFAR detection theory in Radar systems. The other one is the maximum probability of detection (MPD) method, which determines the TOA estimation according to a comparison of the detection probabilities of a number of different possible TOA estimations. The performance of the proposed methods is evaluated and compared with several existing methods by computer simulation using realizations of IEEE802.15.4a channel models.