Non-Line-of-Sight Error Mitigation in Wireless Communication Systems

Szu Lin Su,Yi Wen Su,Chien Sheng Chen,Ho Nien Shou

doi:10.4028/www.scientific.net/aef.1.173

Abstract

When there is non-line-of-sight (NLOS) path between the mobile station (MS) and base stations (BSs), it is possible to integrate many kinds of measurements to achieve more accurate measurements of the MS location. This paper proposed hybrid methods that utilize time of arrival (TOA) at five BSs and angle of arrival (AOA) information at the serving BS to determine the MS location in NLOS environments. The methods mitigate the NLOS effect simply by the weighted sum of the intersections between five TOA circles and the AOA line without requiring priori knowledge of NLOS error statistics. Simulation results show that the proposed methods always give superior performance than Taylor series algorithm (TSA) and the hybrid lines of position algorithm (HLOP).

Highlights

The primary network-based techniques include signal strength, angle of arrival (AOA), time of arrival (TOA), and time difference of arrival (TDOA) techniques
The distance between these base stations (BSs) is d = 3464 m and the mobile station (MS) locations are uniformly distributed in the center cell, as shown in Fig. 1. 10,000 independent trials are performed for each simulation
The circular disk of scatterers model (CDSM) assumes that there is a disk of scatterers around the MS and that signals traveling between the MS and the BSs undergo a single reflection at a scatterer

Summary

Introduction

The primary network-based techniques include signal strength, angle of arrival (AOA), time of arrival (TOA), and time difference of arrival (TDOA) techniques. Due to the reflection or diffraction of the signals between the MS and the BSs, NLOS propagation results in significant errors in the time and angle measurements. We have proposed hybrid geometrical positioning schemes to estimate MS location under the condition that the MS can be heard by only two BSs in [1].

Results

Conclusion