Title :
On Time-of-arrival Positioning in a Multipath Environment
Author :
Qi, Yihong ; Kobayashi, Hisashi ; Suda, Hirohito
Author_Institution :
UWB Group, Nat. Inst. of Inf. & Commun. Technol., Yokosuka
Abstract :
Wireless geolocation in a multipath environment is of particular interest for wideband communications and fast-developing ultrawideband (UWB) technologies. Conventional methods are solely based on first arriving signals. In this paper, it is investigated whether and under what conditions processing delay estimates of multipath components in addition to first arrivals can enhance the positioning accuracy. It is shown that the enhancement depends on two principal factors: strength of multipath components and variance of nonline-of-sight (NLOS) delays. Analytical results, which are derived as an extension of a single-path propagation case (IEEE Trans. Wireless Commun., Feb. 2006), are presented first. Their practical implications are then discussed by examining several numerical examples. Finally, modified schemes of practical interest in a multipath environment are proposed
Keywords :
broadband networks; radionavigation; time-of-arrival estimation; ultra wideband technology; delay estimates processing; first arriving signals; multipath component strength; multipath environment; nonline-of-sight delay variance; single-path propagation case; time-of-arrival positioning; ultrawideband technologies; wideband communications; wireless geolocation; Communications technology; Delay effects; Delay estimation; Laboratories; Maximum likelihood estimation; Mobile communication; Research and development; Statistics; Ultra wideband communication; Ultra wideband technology; Cramer–Rao lower bound (CRLB); generalized CRLB (G-CRLB); maximum a posteriori probability (MAP) estimation; maximum-likelihood estimation (MLE); multipath; time-of-arrival (TOA) positioning;
Journal_Title :
Vehicular Technology, IEEE Transactions on
DOI :
10.1109/TVT.2006.878566
