MGALE: A Modified Geometry-Assisted Location Estimation Algorithm Reducing Location Estimation Error in 2D Case under NLOS Environments

摘要

Positioning of a Mobile Station (MS) is mandatory for implementing emergency call services and providing location-based services. The major problems facing accurate location estimation of the MS are Non-Line-of-Sight (NLOS) propagation and hearability. Thus several location algorithms focusing on NLOS mitigation and addressing hearability problem have been studied. Among these, Geometry-Assisted Location Estimation (GALE) algorithm based on three TOA measurements can estimate the 2D location of the MS with reasonable precision. However 2D GALE scheme fails to meet Federal Communication commission (FCC) requirement for phase 2. Thus, in this paper, we have proposed a modification over 2D GALE algorithm with three TOA measurements to meet the FCC target while preserving the computational efficiency of GALE scheme. Our proposed algorithm considers the geometry of the TOA measurement circles rather than the standard deviation of the TOA measurements. Simulation results show that our algorithm provides better location accuracy compared to 2D GALE algorithm.