时频差精度的时变性影响及补偿估计方法

发布时间：2018-05-30 08:37

本文选题：无源定位 + 时变　；参考：《系统工程与电子技术》2016年03期

【摘要】：到达时差(time difference of arrival,TDOA)和到达频差(frequency difference of arrival,FDOA)/频差无源定位体制中,定位精度取决于时频差参数的估计精度。针对微纳卫星定位系统中时变参数估计性能随累积时间增加会出现恶化的问题,分析了相对频率扩展(relative frequency companding,RFC)对频差方向复模糊函数(complex ambiguity function,CAF)峰的扩展效应,推导了无补偿的RFC对频差估计精度的影响,给出频差估计精度的衰减因子及最优累积时间。在理论分析的基础上,提出一种时变补偿的时频差估计方法,用以克服时变特性引起的时间及频率扩展效应。仿真结果表明,该方法可有效消除参数估计精度的损失,估计精度逼近非时变参数的理论极限。
[Abstract]:In the time difference of arrival (DOA) and the frequency difference of arrival frequency (FDOAA) / frequency-difference passive location system, the location accuracy depends on the estimation accuracy of time-frequency difference (TDOA) parameters. In order to solve the problem that the performance of time-varying parameter estimation in micro-nanosatellite positioning system will deteriorate with the increase of cumulative time, the expansion effect of relative frequency spread relative frequency compounding frequency on the complex ambiguity function of frequency difference direction is analyzed. The influence of uncompensated RFC on the accuracy of frequency difference estimation is deduced, and the attenuation factor and optimal cumulative time of frequency difference estimation accuracy are given. On the basis of theoretical analysis, a time-frequency difference estimation method with time-varying compensation is proposed to overcome the time-frequency spread effect caused by time-varying characteristics. The simulation results show that this method can effectively eliminate the loss of parameter estimation accuracy and approach the theoretical limit of time-varying parameters.
【作者单位】：清华大学电子工程系;清华大学航天航空学院;
【基金】：国家自然科学基金(91338101) 国家重点基础研究发展计划(973计划)(2014CB340206)资助课题
【分类号】：TN95

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