基于脉冲串信号的无源定位系统频差估计误差CRLB分析

CRLB analysis of FDOA estimation accuracy based on pulse trains in passive location system

频差估计是无源定位系统中的关键部分,其估计精度直接决定了无源定位系统的性能。本文对单频脉冲信号频差估计误差方差的Cramer-Rao下限(CRLB)进行了理论分析研究。在建立数学模型的基础上,定量分析了频差估计误差CRLB与接收信号参数的数学关系。通过直接公式推导和数值仿真归纳,分别得出了相参/非相参单频脉冲信号频差估计误差CRLB的解析表达式,该结论可用于指导基于频差估计的无源定位系统设计。

The frequency difference of arrival （FDOA） estimation is the key point in a passive location system, and the estimation accuracy of FDOA determines the location performance. The FDOA estimation methods have been widely studied, but theoretical maximal accuracy of FDOA estimation is barely referred. To explore the ultimate performance of the FDOA estimation, the CRLB of frequency FDOA estimation accuracy was studied. On the basis of building a mathematical model, the quantitative relationship between the FDOA estimation accuracy and the parameters of received signal was investigated. By the means of mathematical deduction and numerical simulation, the algebraic expression of the CRLB was conducted in different application modes. Finally the characteristic of the CRLB was evaluated, and the conclusion can be used to direct the design of passive location system based on FDOA.