一种低轨双星雷达信号无模糊频差估计算法  

A Novel Method for Unambiguous DFO Estimation of Radar Signals in LEO Dual-Satellite Geolocation System

作　　者：姚山峰 贺青 欧阳鑫信 夏畅雄 YAO Shanfeng;HE Qing;OUYANG Xinxin;XIA Changxiong(National Key Laboratory of Blind Signals Processing,Chengdu 610041,China)

机构地区：[1]盲信号处理重点实验室,成都610041

出　　处：《宇航学报》2018年第11期1275-1283,共9页Journal of Astronautics

基　　金：国防科技重点实验室基金(9140C860304)

摘　　要：针对低轨双星组合接收低脉冲重复频率(LPRF)雷达信号的频差(DFO)估计存在模糊的问题,提出一种基于时差差分的频差无模糊高精度估计算法,该算法通过对高精度的时差测量值进行中心差分获得无模糊的频差估值。仿真结果表明,新算法能对PRF低至300 Hz的雷达信号进行无模糊的频差估计,估计精度在信噪比高于15 d B时逼近克拉美劳下界,可有效扩大低轨双星时/频差定位系统对LPRF信号的适用范围。A high-precision estimation algorithm of differential frequency offset(DFO)without ambiguity based on the differential DTO is proposed to estimate the DFO of the low pulse repetition frequency(PRF)radar signals in an LEO dual-satellite geolocation system.The DFO estimation without ambiguity can be estimated using the central difference method of high-precision DTO measurement.The numerical simulations have demonstrated that the effectiveness of the approach proposed can adapt to the radar signals with PRF low to 300 Hz and the estimation accuracy can approximate the Cramer-Rao lower bound(CRLB)with the SNR above 15 dB,which can expand the scope of the application of the LEO dual-satellite DTO/DFO geolocation system.

关 键 词：相参脉冲串 低脉冲重复频率 频差模糊 时差差分 低轨双星时/频差定位 

分 类 号：TN96[电子电信—信号与信息处理]