A NLOS mitigation method for CDMA2000 mobile location

In TDOA cellular mobile location, Non-Line-of-Sight (NLOS) propagation of radio waves brings about the larger errors of TOA/TDOA parameter measurements, thus resulting in location accuracy decreasing seriously. On the basis of TDOA errors analysis and NLOS characteristics investigation, a NLOS mitigation algorithm is proposed in this paper to realize the TDOA smoothing and LOS reconstruction by Kaiman filter in NLOS propagation environment, which effectively inhibits NLOS error of mobile location, so that positioning errors are reduced greatly. Simulation results show that the proposed algorithm can significantly improve the positioning accuracy and performance of TDOA mobile location under NLOS conditions. Combining with the WLS location resolving algorithm, the proposed algorithm can be well applied to mobile location of CDMA2000 cellular networks.

[1]  Markku J. Juntti,et al.  Positioning for NLOS Propagation: Algorithm Derivations and Cramer-Rao Bounds , 2007, IEEE Trans. Veh. Technol..

[2]  Y. Jay Guo,et al.  NLOS Error Mitigation for Mobile Location Estimation in Wireless Networks , 2007, 2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring.

[3]  Jang Gyu Lee,et al.  A mitigation of line-of-sight by TDOA error modeling in wireless communication system. , 2008, 2008 International Conference on Control, Automation and Systems.

[4]  Gérard Lachapelle,et al.  An enhanced two-step least squared approach for TDOA/AOA wireless location , 2003, IEEE International Conference on Communications, 2003. ICC '03..

[5]  J. Holtzman,et al.  The non-line of sight problem in mobile location estimation , 1996, Proceedings of ICUPC - 5th International Conference on Universal Personal Communications.

[6]  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).

[7]  Tian Xiao.  An Effective TOA-Based Location Method for Mitigating the Influence of the NLOS Propagation , 2003 .

[8]  Marilynn P. Wylie-Green,et al.  Robust range estimation in the presence of the non-line-of-sight error , 2001, IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211).

[9]  Gérard Lachapelle,et al.  Practical Results of Hybrid AOA/TDOA Geo-Location Estimation in CDMA Wireless Networks , 2008, 2008 IEEE 68th Vehicular Technology Conference.

[10]  S. Al-Jazzar,et al.  NLOS mitigation method for urban environments , 2004, IEEE 60th Vehicular Technology Conference, 2004. VTC2004-Fall. 2004.

[11]  Heung-Ryeol You,et al.  The NLOS mitigation technique for position location using IS-95 CDMA networks , 2000, Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152).

[12]  James J. Caffery,et al.  Wireless Location in CDMA Cellular Radio Systems , 1999 .

[13]  Luo Xian-yun,et al.  Constrained least-squares and wireless location based on TDOA measurements , 2008 .

[14]  K. C. Ho,et al.  A simple and efficient estimator for hyperbolic location , 1994, IEEE Trans. Signal Process..

[15]  Markku J. Juntti,et al.  Positioning for NLOS Propagation: Algorithm Derivations and Cramer–Rao Bounds , 2006, IEEE Transactions on Vehicular Technology.