双星定位系统定位精度的Cramer-Rao下界分析  

Cramer-Rao Lower Bounds for Position Estimation in Dual-satellite Geolocation System

作　　者：严航 姚山峰 

机构地区：[1]盲信号处理国防科技重点实验室,成都610041

出　　处：《电讯技术》2012年第5期634-639,共6页Telecommunication Engineering

基　　金："十二五"预研项目(40901050301;513210901);国防科技预研基金项目(9140A22020212JB5101)~~

摘　　要：介绍了双星时频差定位原理,在此基础上研究了在地球表面约束条件下的双星定位系统的定位精度理论下界。利用推导的定位精度Cramer-Rao下界,仿真分析了定位参数估计精度、卫星星历、目标辐射源位置以及辐射源载波频率等因素对定位精度的影响,并给出了物理解释。定位仿真试验结果表明,定位精度变化趋势与Cramer-Rao下界一致,证明了理论推导的正确性。The principle of transmitter location using TDOA （Time Difference of Arrival） and FDOA （ Frequency Difference of Arrival） of two satellites is introduced in this paper. Then, the Cromer - Rao Lower Bound （CRLB） for the location accuracy is studied. In the CRLB, the factors such as the estimation accuracy of posi- tioning parameters, the ephemeris, the position of transmitter and the carrier frequency are analysed. The physical explanations are also given. Simulations show the consistance between location accuracy change trend and CRLB and also confirm the correctness of theoretical analysis.

关 键 词：双星定位 时频差 参数测量误差 定位误差 CRAMER-RAO下界 

分 类 号：TN971[电子电信—信号与信息处理]