Maximum likelihood location for identification of line-of-sight base stations

In this paper, we address the problem of time-of-arrival based mobile station location problem in non-line-of-sight condition. Unlike the previous method based on the position residuals test (PRT), a novel method based on the range residuals test (RRT) is proposed. The range residuals are the squared differences between the distance measurements and the distance calculated from approximate maximum likelihood position estimation. Compared with the PRT method, the proposed algorithm has less computational complexity and higher accuracy in determination of line-of-sight base stations