Joint TOA Estimation and NLOS Identification for UWB Localization Systems

In this paper, we propose a new joint time-of-arrival estimation and non-line-of-sight identification approach for ultra-wideband wireless sensor network applications. We use an energy-based time-of-arrival estimation algorithm. The non-line-of-sight detection is based on the direct path to the strongest multipath components ratio of the received signal folded version of the energy-based time-of-arrival estimation algorithm. The non-line-of-sight information is used in the weighted least-squares localization algorithm. The channel models residential LOS and residential NLOS of the standard IEEE802.15.4a are used. Numerical simulations results show that the correct identification of channel models with the proposed approach is better than those based on joint likelihood ratio and the location accuracy obtained by weighted least-squares algorithm using non-line-of-sight information is higher than that obtained by least-square algorithm.