LTE positioning accuracy performance evaluation

Abstract

In this paper we investigate the positioning accuracy of user equipment (UE) with observed time difference of arrival (OTDoA) technique in Long Term Evolution (LTE) networks using dedicated positioning reference signal (PRS) by means of comprehensive simulation model. System-level model includes typical cellular network layout with spatially distributed eNodeB (eNB) and link-level model simulates PRS transmission and reception with LTE System Toolbox. Matlab “TDOA Positioning Using PRS example” was developed to include known linear least squares (LLS), nonlinear Gauss-Newton (GN) and Levenberg-Marquardt (LM) positioning algorithms and compare it with Cramer-Rao lower bound (CRLB). Resulting estimates clarify known results and reveal that simple LLS achieves close to LM positioning accuracy when the number of eNB is 6, while further increasing the number of eNB degrades positioning algorithms accuracy.