An Efficient NLOS Errors Mitigation Algorithm for TOA-Based Localization.

Yanbin Zou,Huaping Liu

doi:10.3390/s20051403

Abstract

In time-of-arrival (TOA) localization systems, errors caused by non-line-of-sight (NLOS) signal propagation could significantly degrade the location accuracy. Existing works on NLOS error mitigation commonly assume that NLOS error statistics or the TOA measurement noise variances are known. Such information is generally unavailable in practice. The goal of this paper is to develop an NLOS error mitigation scheme without requiring such information. The core of the proposed algorithm is a constrained least-squares optimization, which is converted into a semidefinite programming (SDP) problem that can be easily solved by using the CVX toolbox. This scheme is then extended for cooperative source localization. Additionally, its performance is better than existing schemes for most of the scenarios, which will be validated via extensive simulation.

Highlights

Localization of an emitting source has a variety of applications, such as emergency assistance, people and asset tracking, location-based advertising and wireless sensor network [1,2,3,4,5]
Comparisons are made with existing NLOS error mitigation algorithms: [19], [20], [21], and [22] (labeled as semidefinite programming (SDP)-Robust, corresponding to (56) in [22])
An effective scheme is proposed for source localization with TOA measurements, some of which are subject to NLOS errors

Summary

Introduction

Localization of an emitting source has a variety of applications, such as emergency assistance, people and asset tracking, location-based advertising and wireless sensor network [1,2,3,4,5]. Some schemes assume line-of-sight (LOS) signal propagation between the source and sensor, or anchor, which is unrealistic for many environments such as indoors. Errors could drastically degrade the performance if not taken into consideration in the localization process [15,16]. When there are fewer than three remaining nodes for 2D TOA positioning (or four for 3D TOA positioning), the source cannot be localized, but NLOS error mitigation methods are not restricted by the number of LOS nodes [19,20,21,22,23,24,25,26]

Objectives

Results

Conclusion