Analysis of the non-parametric geolocation for cellular location system

Wireless location has now gained considerable attention. One of the main problems facing accurate location in wireless communication systems is non-line-of-sight (NLOS) propagation. There are parametric and non-parametric methods to cope with NLOS errors. Compared with the parametric method, the non-parametric method can provide a unified solution with an optimal performance for different channel environments. Although the non-parametric method has been addressed in the literature, the performance analysis of non-parametric method for cellular location system is still an opening issue. In this paper, the best accuracy of non-parametric method is evaluated in terms of Cramer-Rao lower bounds (CRLBs). The proposed CRLBs consider both the cases that positions of base stations are perfectly or imperfectly known. Since non-parametric kernel method is used to build probability density function of NLOS errors, the proposed CRLBs are suitable for various distributions of NLOS errors. The simulation results verify the proposed CRLBs.