Research on TDOA / AOA hybrid positioning system based on Kalman filtering

Due to non-ideal channel environment, there are plenty of multi-path propagations and NLOS (Non- Line- Of-Sight) propagations between mobile stations and base stations in the cellular networks. All these factors will make the detection of error in measurement of signal characteristics, thus affecting the positioning accuracy. In order to improve the location accuracy of mobile station in the cellular network, two kinds of methods are used. One is to search for realistic channel environmental models for the line-of-sight and the non-line-of-sight propagations to study the characteristics of signal measurements error with good robustness of high-precision positioning algorithms. The other is to analyze the main cause of the different kinds of the measurement errors to find their solutions to decrease the errors.