基于Savitzky-Golay滤波和互模糊函数的时频差参数估计算法

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关键词：参数估计；Savitzky-Golay滤波；互模糊函数；高阶累积量；滑窗 中图分类号：TN971 文献标志码：A DOI：10.12305/j.issn.1001-506X.2025.05.02

Parameter estimation algorithm for time-frequency difference using Savitzky-Golay filtering and cross-ambiguity function

ZHANG You 1，2 ，HUANG Yonghui1，LI Zhihao 1，3 ，CUI Tianshu4，WANG Zhugangl，*

（1.KeyLaboratoryofElectronicsand Information TechnologyforComplex SpaceSystems，NationalSpaceScienceCenter，

ChineseAcademyofSciences，BeijingOol9o，China；2.SchoolofElectronic，ElectricalandCommunicationEnginering， Universityof Chinese Academyof Sciences，Beijing 1O0049，China;3. Schoolof Computer Science and Technology，Universityof Chinese Academy of Sciences，Beijing l0o049，China；4.China Academy of Aerospace Science and Technology Innovation，Beijing1Ooo88，China）

Abstract：Aiming to address the issue of low accuracy in parameter estimates in low signal-to-noise ratio scenarios of time difference and frequency difference ofsmallsatelltes in loworbit with small antennasize and small gain，and the correlation between noise affects the accuracyof parameter estimation，a joint estimation algorithm based on acombination of Savitzky-Golay（S-G）smoothing filtering and cross-ambiguity function （CAF）is proposed.Firstly，the signal is smoothed using S-G filtering to reduce noise.Then，combined with the sliding window segment processing，the high-order cumulant is used to eliminate the influence of noise caused bycorelation.Finally，thetime diference and frequency difference estimates are obtained by searching for the peak value of the CAF.Simulation results show that the proposed algorithm can enhance the precision of time difference estimation by 3.3% and frequency difference estimation by 1.5% compared with the secondorder CAF algorithm under theconditionof一5dB signal-to-noise ratio.Therefore，the proposed algorithm can efectually enhance the precision of theestimation of parameters in non-ideal signal environments，such as low signal-to-noise ratio.

Keywords：parameter estimation；Savitzky-Golay（S-G） filtering；cross-ambiguity function（CAF）；higherordercumulant；sliding window

0 引言

在电子侦察领域，无源定位指系统不主动向被定位的对象发射电磁波，只通过接收电磁波信号对目标做出侦察定位[1。（剩余14346字）