摘要
消除多径误差是提高GPS精度的关键。针对当前GPS抗多径技术复杂度高和实时性差的缺点,提出一种采用最大似然估计的快速迭代优化算法,首先利用Teager-Kaiser算子并结合提出的有效多径门限检测值,在开始阶段提供初始的码延迟估计值,然后再根据修正的牛顿迭代法的最大似然估计方法(FIMLA)提高码延迟估计的精确度,消除多径误差的影响。仿真结果表明,TK-FIMLA提高了码跟踪的稳定性,克服了FIMLA无法提供迭代初始值和容易收敛到局部最优值的问题,并且算法实时性好、抗多径能力优于现有技术,为全球定位系统的优化提供了参考。
Eliminating the multipath error is the key to improve the precision of GPS. In order to deal with the high complexity of current anti-multipath technology of GPS, a fast optimal iteration method based on maximumlikelihood estimation is presented. Firstly, Teager-Kaiser algorithm with the effective multipath threshold values is utilized, and the initial phase delay estimation at the beginning is provided. Then the correctional maximum likelihood estimation method based on the Newton iteration method （FIMLA） tracks the code phase delay accurately. Finally, simulation results show that the TK-FIMLA can improve the stability and tracking performance, and overcome the problem that the FIMLA cannot provide initial iterative value and converge to the local optimal value easily. And contrasting with the other anti-multipath methods, the TK-FIMLA can eliminate the muhipath error more effectively.
出处
《计算机仿真》
CSCD
北大核心
2016年第11期37-41,共5页
Computer Simulation
基金
"十二五"教育部支撑项目(625010213)
