脉冲噪声下基于Sigmoid的LFM信号参数估计  

Parameter estimation of LFM signals based on Sigmoid under impulsive noise

作　　者：王厚友 郭勇 杨立东[1] Wang Houyou;Guo Yong;Yang Lidong(College of Information Engineering,Inner Mongolia University of Science and Technology,Baotou 014000,China;School of Science,Inner Mongolia University of Science and Technology,Baotou 014000,China)

机构地区：[1]内蒙古科技大学信息工程学院,包头014000 [2]内蒙古科技大学理学院,包头014000

出　　处：《电子测量技术》2024年第2期176-184,共9页Electronic Measurement Technology

基　　金：国家自然科学基金(62161040,62201298);内蒙古科技大学创新基金(2019QDLB39);内蒙古科技大学基本科研业务费专项资金项目资助。

摘　　要：由于脉冲噪声具有的短时大幅值特性,使得基于高斯假设的信号参数估计方法无法在脉冲噪声环境下有效估计参数。针对此问题,利用α稳定分布模拟随机脉冲噪声,提出了一种基于Sigmoid-CFRFT的LFM信号参数估计方法。首先,建立了一种自适应Sigmoid函数,证明了信号经过此非线性变换后,信号的2阶矩由无界变为有界,且信号的相位信息保持不变。其次,将变换后的信号进行离散时间CFRFT,建立了数学优化模型,并使用水循环算法搜索最优值点。最后,利用了非标准SαS分布噪声的修正方法,分析了标准和非标准分布下参数估计的性能。仿真结果说明,所提方法不仅可以有效抑制脉冲噪声对LFM信号分数谱特征的影响,而且能够实现低信噪比信号参数的高精度估计。相比于现有的基于非线性变换的参数估计方法,本文方法具有更好的精度,稳定性和噪声鲁棒性。Due to the short-term large value characteristics of impulsive noise,the signals parameter estimation method based on Gaussian hypothesis cannot effectively estimate parameters in impulsive noise environment.To solve this problem,this paper proposes an LFM signals parameter estimation method based on Sigmoid-CFRFT by using alpha stable distribution to simulate random impulsive noise.Firstly,an improved Sigmoid function is established to prove that after this nonlinear transformation,the 2nd moment of the signal changes from unbounded to bounded,and the phase information of the signal remains unchanged.Secondly,the transformed signal is discrete-time CFRFT,a mathematical optimization model for LFM signals parameter estimation is established,and the water cycle algorithm is used to search for the optimal value point.Finally,a correction method for non-standard SαS distribution noise is used,and the performance of parameter estimation under standard and non-standard distribution is analyzed.The simulation results show that the proposed method can not only effectively suppress the influence of impulsive noise on the fractional spectral characteristics of LFM signals,but also achieve high-precision estimation of signals parameters with low signal-to-noise ratio.Compared with the existing parameter estimation methods based on nonlinear transformation,the proposed method has better accuracy,stability and noise robustness.

关 键 词：线性调频信号 SIGMOID函数 简明分数阶傅里叶变换 脉冲噪声 参数估计 

分 类 号：TN911.7[电子电信—通信与信息系统]