Study Of Mobile Station Positioning Technique In MC-DS-CDMA Mobile Communication System

MC-DS-CDMA is a Beyond 3G access technology, which is integrated by DS-CDMA and OFDM. Since mobile positioning operation must be afforded as an increment operation in future cellular network, mobile positioning technology in MC-DS-CDMA system has a wide application prospect.After introducing the wireless cellular network positioning technology in general, this paper elaborates TDOA wireless positioning technology. Then the two processes of mobile positioning are analyzed in detail, which are the estimation of TDOA and the calculation of the position by TDOA value. As for the estimation of TDOA, GCC method is adopted. After introducing Chan algorithm and Taylor algorithm, this paper applies the EKF and the particle filter technique into the positioning by TDOA value. In addition, this paper introduces the TIP 1.5 positioning channel model, and researches the cause of TDOA error, the discriminating and restraining methods of NLOS error. Lastly, this paper introduces the basic theory of OFDM, researches the MC-DS-CDMA system of CDMA-OFDM emphatically, and applies the TDOA downlink positioning technique into the MC-DS-CDMA system. In simulating the positioning procedure, the positioning algorithms are Chan algorithm, NLOS Chan algorithm, EKF algorithm and particle filter algorithm. The simulation results indicate that the particle filter technique is more excellent than EKF and Chan algorithm in the actual channel surroundings and that NLOS restrained Chan algorithm is beneficial to improving the positioning performance in NLOS channel surroundings.