tailieunhanh - Báo cáo hóa học: " Adaptive Mobile Positioning in WCDMA Networks"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Adaptive Mobile Positioning in WCDMA Networks | EURASIP Journal on Wireless Communications and Networking 2005 3 343-353 2005 B. Dong and X. Wang Adaptive Mobile Positioning in WCDMA Networks B. Dong Department of Electrical and Computer Engineering Queen s University Kingston ON Canada K7L 3N6 Xiaodong Wang Department of Electrical Engineering Columbia University New York NY 10027-4712 USA Email wangx@ Received 6 November 2004 Revised 14 March 2005 We propose a new technique for mobile tracking in wideband code-division multiple-access WCDMA systems employing multiple receive antennas. To achieve a high estimation accuracy the algorithm utilizes the time difference of arrival TDOA measurements in the forward link pilot channel the angle of arrival AOA measurements in the reverse-link pilot channel as well as the received signal strength. The mobility dynamic is modelled by a first-order autoregressive AR vector process with an additional discrete state variable as the motion offset which evolves according to a discrete-time Markov chain. It is assumed that the parameters in this model are unknown and must be jointly estimated by the tracking algorithm. By viewing a nonlinear dynamic system such as a jump-Markov model we develop an efficient auxiliary particle filtering algorithm to track both the discrete and continuous state variables of this system as well as the associated system parameters. Simulation results are provided to demonstrate the excellent performance of the proposed adaptive mobile positioning algorithm in WCDMA networks. Keywords and phrases mobility tracking Bayesian inference jump-Markov model auxiliary particle filter. 1. INTRODUCTION Mobile positioning 1 2 3 4 that is estimating the location of a mobile user in wireless networks has recently received significant attention due to its various potential applications in location-based services such as location-based billing intelligent transportation systems 5 and the enhanced-911 E-911 wireless emergence services 6 . In addition