A Weighting Localization Algorithm with LOS and One-Bound NLOS Identification in Multipath Environments

Mobile station (MS) localization often suffers from hybrid line of sight (LOS), one-bound (OB) and multiple-bound (MB) non-line of sight (NLOS) propagation in multipath environments. Due to the unknown propagation path, accurate position estimate of MS is challenging through using the measured angle of departure (AOD), angle of arrival (AOA), and time of arrival (TOA) of signal between MS and base station (BS). To address this problem, a new weighting localization algorithm based on LOS and OB NLOS identification is proposed in this paper. For each propagation path, by utilizing the geometric relation between AOD and AOA, a theoretic threshold is derived to decide whether it is LOS or NLOS propagation. Moreover, in order to further discriminate OB or MB NLOS propagation, an effective cost function is formulated and an iterative OB NLOS identification method is proposed to discard MB NLOS propagation paths. Finally, a weighting localization algorithm is applied for fusing the measured data of LOS and OB NLOS propagation paths. Simulation results demonstrate that simulation of LOS identification method is consistent with theoretic one, and the proposed algorithm can greatly improve the localization accuracy of MS in different multipath environments, especially when LOS path is available. KeywordsLocalization, Line of sight (LOS), One-bound (OB), Multiple-bound (MB), Weighting.