Cdma Cellular Network-based Mobile Station Positioning Method

Recently, consumer desire for security has been the main driving factors of the mobile position location research with the explosive growth of cellular services, and makes a flurry of research and development activities dedicated to position location. The location technologies in cellular network can be loosely grouped into handset-based technologies and network-based technologies. More attention is paid to the latter technologies because it does not need any modification of mobile phone. The mobile station location has been the important service supported by 3GPP and 3GPP2,and the CDMA is main technology selected by the third generation communication, so we dedicate our research to the mobile location in CDMA cellular networks.Hyperbolic location technology based on TDOA measurements is always selected in CDMA networks because of all base stations have been synchronized by the network. The key factor of the position location used measured TDOA signals transmitted from the mobile station is to find the solution of the nonlinear hyperbolic equations. Chan algorithm is a good TDOA location method. It can acquire good location performance when the TDOA measurements obey the Gauss distribution. But in real environment, the measurements always corrupted by the Non-Line-of-Sight (NLOS) error, and the location accuracy of Chan algorithm will decrease dramatically. In this paper, a data fusion model based on different inter stage results calculated by Chan algorithm is proposed. Simulation results show that positioning accuracy of proposed model is better than the Chan algorithm and can reduce the location failure probability obviously with slight increment of calculation time when the location estimates are corrupted by the NLOS error. A location data fusion model is further proposed based on the result of the different base combination to improve the location accuracy in the bad urban environment of previous data fusion model. The simulation results show that it can achieve the anticipated performance with run up of the location time...