The NLOS Error Mitigation Joint Algorithm in Hybrid Positioning System Combining DTMB and GPS

The increasing demands of position information have made the wireless location technology catch more and more attention nowadays. GPS (Global Positioning System) which has been widely used cannot localize successfully indoors and among buildings, its defects are increasingly prominent. Given the acceptable terrestrial digital television signals anytime and anywhere, as well as the advantages of high transmission power, low operating frequency and strict synchronization with absolute time, it is possible to achieve accurate positioning by Digital Television Terrestrial Multimedia Broadcasting (DTMB) and GPS. Electromagnetic waves have to propagate by deflection, refraction and scattering because of the obstructions in the surroundings of transmitting, we call it as Non-Line of Sight (NLOS) propagation, which results in NLOS errors [1]. In this paper we take some further study on the method of NLOS error mitigation based on the hybrid positioning system combining DTMB and GPS in view of a large number of obstacles in the urban environment. This algorithm, referred to as Range Dynamic Compensation and Linear Line of Position Joint Algorithm, can predict the next position of the object, which can be used to compensate the actual measured value for the purpose of reducing the NLOS errors. The Linear Line of Position Algorithm which utilizes the linear statistical location techniques straightforward rather than linearizing the system roughly is then applied to simplify the position coordinates calculations as well as mitigate the residual NLOS errors. The simulation testing result indicates that this joint algorithm significantly improved the location precision in areas with serious NLOS contamination.

[1]  Saipradeep Venkatraman,et al.  A novel ToA location algorithm using LoS range estimation for NLoS environments , 2004, IEEE Transactions on Vehicular Technology.

[2]  Saleh O. Al-Jazzar,et al.  A scattering model based approach to NLOS mitigation in TOA location systems , 2002, Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367).

[3]  Pi-Chun Chen,et al.  A non-line-of-sight error mitigation algorithm in location estimation , 1999, WCNC. 1999 IEEE Wireless Communications and Networking Conference (Cat. No.99TH8466).

[4]  Jin Yu-ang.  Positioning System Using Digital Television Terrestrial Multimedia Broadcasting Signals and GPS Signals , 2010 .

[5]  Ali H. Sayed,et al.  A non-line-of-sight equalization scheme for wireless cellular location , 2003, 2003 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03)..

[6]  Xiang Ji,et al.  Sensor positioning in wireless ad-hoc sensor networks using multidimensional scaling , 2004, IEEE INFOCOM 2004.

[7]  Pak-Chung Ching,et al.  Time-of-arrival based localization under NLOS conditions , 2006, IEEE Transactions on Vehicular Technology.

[8]  J. J. Caffery,et al.  A new approach to the geometry of TOA location , 2000, Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152).

[9]  Lei Mu,et al.  A Novel Location Algorithm Based on Dynamic Compensation Using Linear Location Prediction in NLOS Situations , 2006, 2006 IEEE 63rd Vehicular Technology Conference.