A Non-Line-of-Sight error mitigation method in wireless location system

A key obstacle to high accuracy location is the None Line of Sight (NLOS) transmission of signal in wireless localization. It adds positive error to distance measurements. An effective location algorithm based on nonlinear constraint optimization is proposed to mitigate NLOS errors. The proposed method forms distance error optimization constraint using the geometric relationship between the base stations and mobile station. It improves the location accuracy by calibrating the distance measurements and modifying the objective function. Simulation results show that this new method can efficiently reduce the effect of the NLOS error, and is robust to different NLOS error.