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: Research Article A TOA-AOA-Based NLOS Error Mitigation Method for Location Estimatio | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 682528 14 pages doi 2008 682528 Research Article A TOA-AOA-Based NLOS Error Mitigation Method for Location Estimation Hong Tang 1 Yongwan Park 1 and Tianshuang Qiu2 1 Mobile Communication Laboratory Yeungnam University kyongsan kyongbuk 712-749 South Korea 2 School of Electronic and Information Engineering Dalian University of Technology Liaoning 116024 China Correspondence should be addressed to Yongwan Park ywpark@ Received 28 February 2007 Revised 21 July 2007 Accepted 31 October 2007 Recommended by Sinan Gezici This paper proposes a geometric method to locate a mobile station MS in a mobile cellular network when both the range and angle measurements are corrupted by non-line-of-sight NLOS errors. The MS location is restricted to an enclosed region by geometric constraints from the temporal-spatial characteristics of the radio propagation channel. A closed-form equation of the MS position time of arrival TOA angle of arrival AOA and angle spread is provided. The solution space of the equation is very large because the angle spreads are random variables in nature. A constrained objective function is constructed to further limit the MS position. A Lagrange multiplier-based solution and a numerical solution are proposed to resolve the MS position. The estimation quality of the estimator in term of biased or unbiased is discussed. The scale factors which may be used to evaluate NLOS propagation level can be estimated by the proposed method. AOA seen at base stations may be corrected to some degree. The performance comparisons among the proposed method and other hybrid location methods are investigated on different NLOS error models and with two scenarios of cell layout. It is found that the proposed method can deal with NLOS error effectively and it is attractive for location estimation in cellular networks. Copyright 2008 Hong Tang et al. This is .
