共查询到19条相似文献，搜索用时 421 毫秒
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针对单通道情况下传统盲源分离方法难以恢复源信号的问题,提出一种基于变分模态分解(VMD)的单通道信号盲源分离方法。首先对单通道信号进行变分模态分解(VMD)获得一系列本征模态函数(IMF)分量,将单通道信号和其IMF分量构成多维信号,然后采用主成分分析法估计源数,依据估计的源信号数目重组多通道观测信号,最后利用改进的变步长等变自适应分离(VSEASI)算法实现信号的盲分离。将所提出方法应用于齿轮和轴承的单通道信号仿真研究,仿真结果表明,该方法能够有效地分离出齿轮和轴承信号,解决了单通道信号盲源分离问题。 相似文献
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针对现有盲源分离方法存在的源信号类型和高斯信号个数受限制问题,提出一种基于非线性函数和简化粒子群优化的盲源分离新算法.算法采用依据源信号类型选取的非线性函数作为目标函数,运用简化粒子群优化算法对目标函数进行优化,实现多类型源信号同时混合的盲源分离.仿真结果表明,本算法能够有效实现源信号为多类型和含有2路高斯信号的盲源分离.与其他算法相比,本算法收敛速度更快,分离精度更高. 相似文献
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多目标无限方差网络攻击作为一种新的病毒攻击方式,对网络安全造成严重威胁,通过对多目标攻击源的时频盲源分离,准确检测和发掘攻击信号源和特征,提高检测性能。传统方法中对攻击源的分离算法采用随机场谱峰搜索算法,存在计算量大的问题。提出一种基于近场源DOA估计的多目标无限方差网络攻击下时频盲源分离算法。为了提高多目标无限方差网络攻击近场源的识别概率,对提取得到的波束域约束指向性特征输出结果进行频分复用分解,通过时频特征提取,得到相关的攻击信号源参数,在多目标无限方差网络攻击近场源模型中,设计匹配滤波器,把近场源的参数估计问题变成了一个三维参数联合DOA估计问题,实现对网络攻击源时频盲源分离。仿真结果表明,具有较好的网络攻击时频盲分离性能,对攻击源估计的均方根误差较传统算法明显减小,实现了对攻击信源的准确识别和检测。 相似文献
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盲信号处理理论研究目前主要集中在盲信号分离(BSS)和盲系统辨识(BSI)两个方向上。文章从介绍信号分离技术的概念开始,在对盲信号分离技术的发展现状进行分析的基础上,对盲信号分离技术中的自适应盲信号分离算法进行了重点解析。 相似文献
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盲源分离技术能够帮助完成机械设备的故障诊断,其中,单通道盲源分离技术正是该领域研究的热点。学者们在该领域以机械振动信号作为研究对象应用最为广泛,在此基础上,本文针对单通道的转动机械声音信号盲源分离进行讨论,为机械声学故障诊断的发展奠定基础。 相似文献
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针对后非线性盲源分离中非线性参数估计中存在的问题,提出一种基于改进的自适应遗传算法的后非线性盲源分离方法.该方法给出一种新的适应度函数,利用适应度函数值反馈调节交叉概率和变异概率的选取,并将优先进化策略和模拟退火机制引入遗传算法中,再通过线性分离算法得到分离矩阵.仿真验证表明,该方法较传统方法具有更快的收敛速度和较高的分离精度. 相似文献
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为确保无线通信的可靠性,提出一种有效的基于盲源分离算法的无线通信系统抗干扰算法。针对扩频通信系统进行建模设计,算法使用Hessian矩阵判定得到的有用解是否为最值点,作为信噪分离过程稳定性的判定统计点,作权系数的修订,对扩频通信系统中的盲源分离算法进行了建模,改善扩频通信系统受到复杂电磁环境干扰性能。仿真实验表明通过新的盲源分离抗干扰算法,整个扩频通信系统的信噪比以及抗干扰性能得到了很大的提高,与传统小波处理以及统计信噪分离算法相比,整体信噪比平均提高了4 dB,展示了算法在扩频通信中具有较好的抗干扰性能,在无线通信抗干扰系统设计中具有较好的实际应用价值。 相似文献
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Juha Karvanen 《Journal of The Franklin Institute》2004,341(5):401-418
This paper introduces blind separation methods that are based on minimization of mutual information. Direct minimization of mutual information leads to estimating functions that change on every iteration of separating algorithm unlike in the maximum likelihood approach employing fixed non-linearity. We propose objective functions for source separation that are comprised of a symmetric and an asymmetric part. This allows for separating signals that may have skewed distributions. The optimal weighting between the symmetric and the asymmetric part is determined from the data based on an efficacy measure. The performance of the proposed objective functions is studied in cases where some source signals may be asymmetrically distributed. The capability of adapting to different type of source distributions is demonstrated in simulations. 相似文献
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针对基于传统的密码算法保密电话数据加密存在的缺陷,提出一种基于成对载波和混沌加密技术的保密电话解决方案。该方案用成对载波和回波抵消的体制保证语音信号的安全,用密码的方法保证整个数字传输通信系统的安全性,因此,电话系统保密性更高,实用性更强。 相似文献
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《Journal of The Franklin Institute》2023,360(5):3700-3749
This paper investigates the problem of master-slave synchronization of stochastic quaternion-valued neural networks (SQVNNs) with mixed time-varying delays. A linear feedback controller is developed to explore the global synchronization of the proposed system by utilizing the complete information of the time-delay state. Sufficient conditions for synchronization of the proposed model are derived by constructing appropriate Lyapunov–Krasovskii functional by applying the master-slave synchronization method of master-slave and some integral inequality techniques. Finally, a corresponding numerical simulation is presented to demonstrate the accuracy of the theoretical results. This paper introduces a unique and efficient image encryption algorithm based on SQVNNs. This technique utilizes the solution set of SQVNNs to generate the high-level randomness secret keys to encrypt the source image. Finally, we conclude that the algorithm yields a source image cipher with excellent diffusion and confusion properties. A few test clinical images are utilized to show the validity of the proposed method. Several performance analyses show that the proposed algorithm for image encryption gives an efficient and secure way to deal with the Internet of Health Things (IoHT). 相似文献
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一种基于位置变换和灰度变换相结合的数字图像置乱方法 总被引：1，自引：0，他引：1
图像置乱技术在数字图像加密中有着广泛应用。作为一种图像加密技术,它主要通过改变原图像中各像素位置或改变像素灰度值的方式达到对图像信息进行隐藏的目的。提出一种易于实现的将像素位置变换和像素灰度变换相结合的数字图像置乱方法。实验证明该方法相对传统算法置乱效果得到明显加强。 相似文献
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传统的信道辨识和均衡是通过发送训练序列来完成的。近年来通信技术的迅速发展,自适应均衡技术已经暴露出许多不足,因此盲信道辨识与均衡技术越来越受到重视。本文介绍了码间干扰产生以及盲均衡技术的数学原理,并对几种常用的盲均衡算法进行了研讨。 相似文献
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Zois Boukouvalas Yuri Levin-Schwartz Vince D. Calhoun Tülay Adalı 《Journal of The Franklin Institute》2018,355(4):1873-1887
Because of its wide applicability in various disciplines, blind source separation (BSS), has been an active area of research. For a given dataset, BSS provides useful decompositions under minimum assumptions typically by making use of statistical properties—types of diversity—of the data. Two popular types of diversity that have proven useful for many applications are statistical independence and sparsity. Although many methods have been proposed for the solution of the BSS problem that take either the statistical independence or the sparsity of the data into account, there is no unified method that can take into account both types of diversity simultaneously. In this work, we provide a mathematical framework that enables direct control over the influence of these two types of diversity and apply the proposed framework to the development of an effective ICA algorithm that can jointly exploit independence and sparsity. In addition, due to its importance in biomedical applications, we propose a new model reproducibility framework for the evaluation of the proposed algorithm. Using simulated functional magnetic resonance imaging (fMRI) data, we study the trade-offs between the use of sparsity versus independence in terms of the separation accuracy and reproducibility of the algorithm and provide guidance on how to balance these two objectives in real world applications where the ground truth is not available. 相似文献
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为解决频城内卷积混合乐音盲分离存在的顺序不确定问题,提出了基于频带间复数平均相关的调序算法,对每个频带的分离子信号进行顺序调整。仿真实验结果验证了该算法的有效性,与已有的基于幅值相关和能量相关的调序方法相比,其分离性能更优。 相似文献