Non-Line-of-Sight Localization in Multipath Environments

This paper presents a comprehensive Non Line of Sight (NLOS) localization scheme and a least square estimator that leverages on the bi-directional estimation of the Angle of Arrival (AOA) and Time of Arrival (TOA) of signals exchanged between mobile and reference devices. The proposed localization scheme requires two or more signal paths which can be either Line of Sight (LOS) signals or Non-line of Sight (NLOS) multipath signals that undergo one bound scattering. Our multipath selection scheme is shown to be able to discard multiple bound scattering paths with a high degree accuracy. We used empirical data obtained through experimentation in a real environment to analyse the performance of our proposed localization scheme, and to compare it to the existing methods. The results of this experiment show that the proposed localization scheme that just uses two signal paths, is able to outperform the existing localization schemes in both LOS and extreme NLOS situations where all reference devices are in NLOS with the mobile device. This localization approach is very useful in multipath environments where it may not always be possible to have at least three reference devices in LOS with the mobile device.

[1]  Henry Tirri,et al.  A Statistical Modeling Approach to Location Estimation , 2002, IEEE Trans. Mob. Comput..

[2]  S. Y. Tan,et al.  Improved three-dimensional ray tracing technique for microcellular propagation models , 1995 .

[3]  Pulkit Grover,et al.  Geolocation using transmit and receive diversity , 2004, IEEE Global Telecommunications Conference, 2004. GLOBECOM '04..

[4]  Martin Haardt,et al.  Smart antenna technologies for future wireless systems: trends and challenges , 2004, IEEE Communications Magazine.

[5]  Xin Wang,et al.  A TOA-based location algorithm reducing the errors due to non-line-of-sight (NLOS) propagation , 2001, IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211).

[6]  K. C. Ho,et al.  A simple and efficient estimator for hyperbolic location , 1994, IEEE Trans. Signal Process..

[7]  Dana H. Brooks,et al.  Closed-form solution for positioning based on angle of arrival measurements , 2002, The 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications.

[8]  R.L. Moses,et al.  Locating the nodes: cooperative localization in wireless sensor networks , 2005, IEEE Signal Processing Magazine.

[9]  Juha-Pekka Makela,et al.  Indoor geolocation science and technology , 2002, IEEE Commun. Mag..

[10]  Thomas Kaiser.  When will smart antennas be ready for the market? Part I , 2005 .

[11]  A.H. Sayed,et al.  Network-based wireless location: challenges faced in developing techniques for accurate wireless location information , 2005, IEEE Signal Processing Magazine.

[12]  Li Xiong,et al.  A selective model to suppress NLOS signals in angle-of-arrival (AOA) location estimation , 1998, Ninth IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (Cat. No.98TH8361).

[13]  Henry Tirri,et al.  A Probabilistic Approach to WLAN User Location Estimation , 2002, Int. J. Wirel. Inf. Networks.

[14]  Weihua Zhuang,et al.  Hybrid TDOA/AOA mobile user location for wideband CDMA cellular systems , 2002, IEEE Trans. Wirel. Commun..

[15]  Qiang Sun,et al.  Analytical formulae for path loss prediction in urban street grid microcellular environments , 2005, IEEE Transactions on Vehicular Technology.

[16]  Weihua Zhuang,et al.  Nonline-of-sight error mitigation in mobile location , 2004, IEEE INFOCOM 2004.

[17]  Ali H. Sayed,et al.  A non-line-of-sight equalization scheme for wireless cellular location , 2003, 2003 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03)..

[18]  J. Conan,et al.  Mobile Station Location Estimation for MIMO Communication Systems , 2006, International Symposium on Wireless Communication Systems.

[19]  Thomas Kaiser.  When will smart antennas be ready for the market? Part II - results , 2005 .

[20]  Robert A. Scholtz,et al.  Ranging in a dense multipath environment using an UWB radio link , 2002, IEEE J. Sel. Areas Commun..

[21]  Trevor F. Cox.  An Introduction to Multivariate Data Analysis , 2005 .

[22]  Pi-Chun Chen,et al.  A non-line-of-sight error mitigation algorithm in location estimation , 1999, WCNC. 1999 IEEE Wireless Communications and Networking Conference (Cat. No.99TH8466).

[23]  S. Kay.  Fundamentals of statistical signal processing: estimation theory , 1993 .

[24]  Daniel Pérez Palomar,et al.  Space-Time Processing for MIMO Communications , 2004 .

[25]  Theodore S. Rappaport,et al.  An overview of the challenges and progress in meeting the E-911 requirement for location service , 1998, IEEE Commun. Mag..

[26]  Moe Z. Win,et al.  Evaluation of an ultra-wide-band propagation channel , 2002 .

[27]  Shlomo Shamai,et al.  On the achievable throughput of a multiantenna Gaussian broadcast channel , 2003, IEEE Transactions on Information Theory.

[28]  N.B. Mandayam,et al.  Decision theoretic framework for NLOS identification , 1998, VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151).

[29]  Saipradeep Venkatraman,et al.  Location using LOS range estimation in NLOS environments , 2002, Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367).

[30]  Soon Yim Tan,et al.  A microcellular communications propagation model based on the uniform theory of diffraction and multiple image theory , 1996 .

[31]  Joseph Kee-Yin Ng,et al.  Location Estimation via Support Vector Regression , 2007, IEEE Transactions on Mobile Computing.

[32]  William G. Scanlon,et al.  Stepwise Algorithms for Improving the Accuracy of Both Deterministic and Probabilistic Methods in WLAN-based Indoor User Localisation , 2004, Int. J. Wirel. Inf. Networks.

[33]  Hisashi Kobayashi,et al.  Analysis of wireless geolocation in a non-line-of-sight environment , 2006, IEEE Transactions on Wireless Communications.

[34]  Pak-Chung Ching,et al.  Time-of-arrival based localization under NLOS conditions , 2006, IEEE Transactions on Vehicular Technology.

[35]  Michael A. Jensen,et al.  Modeling the statistical time and angle of arrival characteristics of an indoor multipath channel , 2000, IEEE Journal on Selected Areas in Communications.

[36]  J.R. Fonollosa,et al.  Antennas: state of the art , 2006, IEEE Vehicular Technology Magazine.

[37]  Markku J. Juntti,et al.  Positioning for NLOS Propagation: Algorithm Derivations and Cramer–Rao Bounds , 2006, IEEE Transactions on Vehicular Technology.