电子测量与仪器学报

陈梦,行鸿彦,王海峰.脉冲噪声下基于 NAT 函数的 LFM 信号多径时延估计[J].电子测量与仪器学报,2022,36(7):73-81

脉冲噪声下基于 NAT 函数的 LFM 信号多径时延估计

Multipath time delay estimation method of LFM signalsbased on NAT function in impulsive noise

DOI：

英文关键词:multipath time delay estimation nonlinear amplitude transformation α-stable distribution fractional Fourier transform (FRFT)

基金项目:国家重点研发计划(2021YFE0105500)、国家自然科学基金( 62171228) 项目资助

作者	单位
陈梦	1. 南京信息工程大学江苏省气象灾害预报预警与评估协同创新中心，2. 南京信息工程大学江苏省气象探测与信息处理重点实验室
行鸿彦	1. 南京信息工程大学江苏省气象灾害预报预警与评估协同创新中心，2. 南京信息工程大学江苏省气象探测与信息处理重点实验室
王海峰	1. 南京信息工程大学江苏省气象灾害预报预警与评估协同创新中心，2. 南京信息工程大学江苏省气象探测与信息处理重点实验室

Author	Institution
Chen Meng	1. Jiangsu Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science & Technology,2. Jiangsu Key Laboratory of Meteorological Detection and Information Processing
Xing Hongyan	1. Jiangsu Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science & Technology,2. Jiangsu Key Laboratory of Meteorological Detection and Information Processing
Wang Haifeng	1. Jiangsu Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science & Technology,2. Jiangsu Key Laboratory of Meteorological Detection and Information Processing

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中文摘要:

针对脉冲噪声环境下无法准确估计线性调频(LFM)信号多径时延的问题,分析非线性幅值变换法抑制脉冲噪声的原理,设计了一种新的非线性幅值变换函数 P-NAT(piecewise-NAT)函数,证明了任意随机变量经该函数变换后存在有限二阶矩, 提出了基于 P-NAT 函数的 LFM 信号多径时延估计方法。分别对发射信号和 P-NAT 函数变换后的含噪多径接收信号进行最佳阶次 FRFT,根据 FRFT 域的峰值位置偏移量和时延的关系,实现 LFM 信号的多径时延估计。仿真结果表明,该方法在广义信噪比为 0 dB、噪声特征指数大于 0. 2 的情况下,时延估计归一化均方根误差小于 10 -4 ,适用于低信噪比和强脉冲噪声环境下的 LFM 信号多径时延估计。

英文摘要:

In order to solve the problem that it is difficult to accurately estimate the multipath time delay of linear frequency modulation (LFM) signals in impulse noise environment, this paper designs a new nonlinear amplitude transformation function P-NAT (piecewiseNAT) function, and proves that any random variable has finite second-order moment after transformation by this function, a multipath time delay estimation method of LFM signals based on P-NAT function is then proposed. The optimal order FRFT is performed on the transmitted signal and the noisy multipath received signal transformed by P-NAT function respectively. According to the relationship between peak position offset in FRFT domain and the time delay, the multipath time delay estimation of the LFM signal is realized. Simulation results show that this method is superior to fractional lower order statistics method and myriad filter method in impulse noise suppression, when the generalized signal-to-noise ratio is 0 dB, the normalized root mean square error of time delay estimation is less than 10 -4 . It is suitable for multipath time delay estimation of LFM signals in low signal-to-noise ratio and strong impulse noise environment.

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