Location using LOS range estimation in NLOS environments

Abstract

We present an algorithm for mitigating the non-line-of-sight (NLOS) error that corrupts time of arrival (TOA), or range, measurements. The method uses the available data regarding the ranges and the base station (BS) layout, in conjunction with cell geometry, to adjust the measured ranges to near their true line-of-sight (LOS) values. The range adjustments are obtained by scaling the NLOS ranges using scale factors that are estimated from a constrained nonlinear optimization problem.