基于广义循环相关熵的改进MSK载波估计方法研究  

Improved MSK Carrier Estimation Method Based on Generalized Cyclic Correntropy

作　　者：孔垚 付天晖[1] KONG Yao;FU Tianhui(College of Electronic Engineering,Naval University of Engineering,Wuhan,Hubei 430033,China)

机构地区：[1]海军工程大学电子工程学院,湖北武汉430033

出　　处：《信号处理》2024年第12期2116-2125,共10页Journal of Signal Processing

基　　金：国家自然科学基金(42174051)。

摘　　要：针对甚低频通信中常用的最小频移键控(Minimum shift keying,MSK)信号在传输过程中由于雷击引起的强脉冲性的噪声干扰,原有的基于广义循环相关熵的估计算法对这种强脉冲噪声的抑制性能下降,导致载波参数估计能力的退化甚至失效的问题,本文算法通过引入非线性函数Sigmoid,提出一种基于广义循环相关熵的改进的载波估计(Sigmoid generalized cyclic correntropy,SGCCE)方法。首先,指出广义循环相关熵算法在脉冲噪声背景下实现载波估计的特性,以及算法退化甚至失效的原因。然后根据Sigmoid函数可以有效抑制强脉冲噪声且保持MSK信号特征不变的特性,利用Sigmoid函数改进广义循环相关熵算法中的广义高斯核函数,再通过数学建模推导出MSK信号的SGCCE函数,并由此推出MSK信号的广义循环相关熵谱(Sigmoid generalized cyclic correntropy spectrum,SGCCES),在SGCCES的基础上验证谱截面上循环频率和载波频率的关系,并检索正半轴中最大谱峰位置实现载波频率估计。本文算法使用有界非线性函数对原信号中的强脉冲噪声进行幅度抑制,实现对原算法载波估计性能的改进,通过与不同的谱函数对比,计算机仿真结果表明,本文改进的载波估计算法相比原有算法在Alpha稳定分布噪声特征指数较小,信号的广义信噪比(Generalized signal-to-noise ratio,GSNR)较低时具有较高的估计准确度,能保持良好的估计性能,并能够实现对载波频率的有效估计,验证了该算法对强脉冲环境下载波频率估计的性能的影响。For the minimum shift keying(MSK)signals commonly used in submarine VLF communications,the atmo‐spheric noise generated by lightning strikes during transmission has a wide spectrum in which the high-frequency compo‐nent decays rapidly with distance.However,the very low-frequency component decays slowly within a spherical wave‐guide,significantly affecting the transmission of signals far from the field source.In particular,when lightning strikes cause strong impulsive noise,the original estimation algorithm based on the generalized cyclic correlation entropy de‐grades the suppression performance of such strong impulsive noise,leading to the degradation of the carrier parameter estimation ability or even the failure of the problem.In this study,an improved carrier estimation algorithm based on generalized cyclic correlation entropy is proposed by introducing a non-linear function,the sigmoid generalized cyclic correlation entropy or generalized cyclic correlation entropy,(SGCCE)method.First,the generalized cyclic correla‐tion entropy algorithm achieves the characteristics of carrier estimation under the background of impulse noise,and the reasons for the degradation or even failure of the algorithm are elucidated.Then,based on the characteristic that the sig‐moid function can effectively suppress the strong impulse noise and maintain the MSK signal characteristics unchanged,the generalized Gaussian kernel function in the generalized cyclic correlation entropy algorithm is improved using the sigmoid function,and then the SGCCE function of the MSK signal is derived by mathematical modeling.Further,the SGCCE function of the MSK signal is introduced,followed by the generalized cyclic correntropy spectrum of the MSK signal(sigmoid generalized cyclic correntropy spectrum,SGCCES).Then,the generalized cyclic correntropy spectrum(SGCCES)of the MSK signal is introduced,the relationship between the cyclic frequency and the carrier frequency in the spectral cross-section is verified based on the SGCCES,and the posi

关 键 词：脉冲噪声 广义循环相关熵 ALPHA稳定分布 SIGMOID 载波估计 

分 类 号：TN914.3[电子电信—通信与信息系统]