Study On High Precision Location Technique Based On Mobile Broadcasting Network

With the dramatic growth of the mobile subscribers and telecommunication traffics,LBS services supported by mobile positioning play an increasingly important role in many fields,such as emergency rescue,public security,industry location tracking and personal positioning and navigation.Meanwhile,it also demands for the higher precision of positioning technology.Currently,with the limitation of the signal bandwidth and the base station synchronization precision,positioning accuracy of ground-based mobile positioning system can not meet the requirement of high-precision LBS business development.It will help lead to the promotion of our positioning and navigation technology and service level by using the mobile broadcasting network resources and advantages,breaking through the bottlenecks of positioning accuracy based on terrestrial wireless network,and realizing mobile broadcasting network-based high-precision positioning of mass users,which has great strategic significance and application value for promoting the rapid development of LBS.The research of the dissertation focuses on terrestrial mobile broadcasting network-based key technical issues of high-precision mobile users positioning,explores such key issues in mobile broadcast channel as the improvement of TDOA positioning accuracy,NLOS mitigation of positioning algorithm,and grid positioning under complex circumstances.The dissertation mainly deals with the broadcast channel characteristics and models of mobile broadcasting positioning,TDOA positioning technology in LOS environment,NLOS mitigation and TDOA remodeling positioning technology under NLOS circumstances,the grid feature matching positioning technology in a complex environment,and design and implementation of mobile broadcasting network positioning experiment system.The main research and contributions in the dissertation are as follows:(1)The transmission fading model,multipath and delay distribution characteristics of mobile broadcasting channel are analyzed.With the combination of COST259 model and Greenstein's delay spread model,the delay error model of mobile broadcasting network TDOA positioning is given.(2)The mobile broadcasting network positioning program is proposed and TDOA positioning model and positioning algorithms in LOS environment are analyzed and investigated.Based on the geometric distribution of positioning base stations,a multi-station TDOA positioning method fused with GDOP weighted mobile station location estimation is put forward.Location estimate calculated based on the weighted GDOP factor of positioning BS combination can effectively decrease the precision dilution of TDOA ranging,and realize optimal location estimates of multi-station TDOA positioning.The simulations show that in a multi-BS positioning,the accuracy of mobile station positioning estimation can be effectively improved.(3)Aiming at positioning errors caused by non-line-of-sight due to block and signal reflection in mobile broadcasting wireless channel,a NLOS suppression positioning algorithm based on biased Kalman filter and TDOA reconstruction is proposed.Combined with statistical properties of NLOS,NLOS error estimate is adopted as the filter state component to correct and.achieve TDOA data reconstruction.Simulation data and analysis show that the algorithm can effectively weaken the impact caused by NLOS errors,and significantly improve mobile positioning accuracy.(4)Directing at NLOS and serious shadow fading in complex indoor environment,a RSSI-TDOA based grid multi-feature parameter fusion matching positioning method is proposed.The research on some key technologies is carried on,such as grid characteristics parametric modeling,intelligent grid division,the quick search of two-dimensional grid and the optimal matching algorithm of feature vector.Simulation data show that,compared with traditional geometric range positioning mode,the algorithm,with comprehensive utilization of the relative stability of time delay and the signal strength discrimination,significantly reduces the error source,effectively improves the accuracy rate and positioning accuracy of grid matching.(5)Based on the mobile broadcasting single frequency network,mobile broadcasting data frame-based embedded positioning signal and IPTS time division inter-cut control method of positioning signals are designed.A system scheme of mobile broadcasting network positioning experiment is performed.A mobile broadcasting-based TDOA positioning experiment system,with the test results in different environments,is designed and achieved.Finally,the research work is summarized,and the direction for further research is pointed out.