AN NON-LINE-OF-SIGHT DETECTION ALGORITHM ON THE MOBILE PHONE WITH 3-AXIS ACCELEROMETER SENSOR

摘要

When the mobile device user meet the obstacles in the walking, non-line-of-sight (NLOS) errors happen in Time Difference of Arrival (TDOA) -based location system, which make the tracking accuracy low. Existing proposals failed when the gap between a NLOS condition and a line-of-sight (LOS) condition is not obvious. In this paper, we propose a new algorithm to solve this problem, which utilizes Chauvent's criteria to detect a NLOS error, when the abnormal change of the difference between the user's predicted and measured location is identified. The user's predicted location information is estimated by the user's step size information obtained from 3-axis accelerometer sensor in the mobile phone. Simulation results show that the proposed algorithm improved NLOS error detection about 17.3%.