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1.
基于单个频点的水声信号盲源分离   总被引:4,自引:1,他引:3  
该文提出基于单个频点的卷积信号盲源分离方法,利用该方法不但可以有效克服频域盲分离过程中排序不确定问题,而且在分离过程中,无需考虑幅度不一致问题。将该方法用于水声信号的盲分离,仿真结果表明基于单个频点盲源分离方法能够很好地分离水声卷积混合信号。与基于两个频点盲源分离方法相比较,其分离效果更优,并且能有效节省CPU运算时间,因而更适合于对信号进行实时处理。  相似文献   

2.
胡波  赵青  凌燮亭 《通信学报》1999,20(2):2L-1
本文提出了一个新的基于盲信号分离的信道均衡结构和算法。通过对接收信号的过采样,由源序列构成的、长度为N的矢量可以被看成互相独立的N个信号源,与此相应的接收矢量则是该N个独立信号通过线性系统后的输出。为了恢复被传送的序列,我们采用基于神经网络学习的盲信号分离算法,实现信道的盲均衡。模拟结果显示,无论是实信道还是复数信道,该方法都具有较好的均衡效果。  相似文献   

3.
水声信道环境恶劣,尤其是多径效应常会造成水声通信系统同步位置发生偏移,对均衡算法造成严重影响。从提高均衡算法稳健性的角度出发,在稳定性较高的归一化常数模算法基础上,借助早迟积分比相原理完成对采样位置的跟踪,并结合判决正方形方法提出一种归一化修正常模盲均衡算法。仿真结果表明,这种基于判决正方形的归一化修正常模盲均衡算法具有更好的收敛能力与稳定性,具有较强的抗干扰能力,能保证水声通信高效运行。  相似文献   

4.
水声信道环境恶劣,尤其是多径效应常会造成水声通信系统同步位置发生偏移,对均衡算法造成严重影响。从提高均衡算法稳健性的角度出发。在稳定性较高的归一化常数模算法基础上,借助早迟积分比相原理完成对采样位置的跟踪,并结合判决正方形方法提出一种归一化修正常模盲均衡算法。仿真结果表明.这种基于判决正方形的归一化修正常模盲均衡算法具有更好的收敛能力与稳定性,具有较强的抗干扰能力,能保证水声通信高效运行。  相似文献   

5.
盲源分离(BBS )作为一门与信息理论、信号处理、人工神经网络、概率论等学科均有交叉的新兴研究领域,得到了研究学者们的热切关注。阐述了盲源分离的概念,介绍了其分类,分析了其应用领域,归纳了盲源分离的国内外发展近况及趋势,并对未来进行了展望。  相似文献   

6.
水声信道的带宽极为有限,与需要训练序列的自适应均衡算法相比盲均衡技术节省了带宽,特别适合高速水声通信和多点通信。针对基于高阶统计量的盲均衡算法收敛速度慢的缺点,研究了一种基于支持向量机的盲均衡算法,它收敛速度快并具有全局最优解。通过对浅海信道触发通信信号的计算机仿真,证明了算法的有效性。  相似文献   

7.
排序和幅度不一致性是信号频域盲源分离的主要困难。该文建立了邻近频点相关特性理论,并针对水声信号进行深入研究,结论表明单个水声信号邻近频点间相关特性良好,且性能非常稳定;而两个不同水声信号邻近频点相关性非常弱。提出基于邻近频点相关特性的盲源分离算法,用于消除卷积信号盲源分离过程中排序不确定性,实验表明该方法对卷积混合形式的水声信号能取得较好分离效果。  相似文献   

8.
由于对管道声波信号进行分析时,会有许多不确定的信号源干扰因素,在实际生产应用中更是受到现实环境制约影响从而导致检测结果并不准确。本文通过对分离信号进行了时域和频域信号分析,表明分离信号具有极大的实用性,为管道预警技术的研究提供了新的研究方法和途径。  相似文献   

9.
传统的信号分选算法建立在脉冲描述字(PDW)参数分析的基础上,对同频或频谱混叠的雷达信号可能无法分选.鉴于越发明显的常规雷达信号处理方法的局限性,通过仿真手段,用盲源分离的方法对混合后的雷达信号进行分选.仿真结果表明,该方法可对雷达盲信号进行有效的分离,且不需要其它信号处理方法所要求的任何先验知识作为条件.  相似文献   

10.
如何提高雷达的抗干扰能力一直是雷达信号处理的一大问题,问题的解决可以使雷达的检测和跟踪能力得以提高.在日趋复杂的信号环境下,传统的信号处理方法的局限性愈来愈大.本文通过对雷达信号处理过程和盲源分离技术的分析研究,提出采用基于高斯矩的ICA/BSS盲源分离方法进行雷达抗干扰信号处理.通过仿真试验结果证明基于盲源分离的雷达抗干扰处理方法是可行和令人满意的.  相似文献   

11.
This letter investigates an improved blind source separation algorithm based on Maximum Entropy (ME) criteria. The original ME algorithm chooses the fixed exponential or sigmoid ftmction as the nonlinear mapping function which can not match the original signal very well. A parameter estimation method is employed in this letter to approach the probability of density function of any signal with parameter-steered generalized exponential function. An improved learning rule and a natural gradient update formula of unmixing matrix are also presented. The algorithm of this letter can separate the mixture of super-Gaussian signals and also the mixture of sub-Gaussian signals. The simulation experiment demonstrates the efficiency of the algorithm.  相似文献   

12.
Analysis of individual noise sources in pre-nanometer circuits cannot take into account the evolving reality of multiple noise sources interacting with each other. Noise measurement made at an evaluation node will reflect the cumulative effect of all the active noise sources, while individual and relative severity of various noise sources will determine what types of remedial steps can be taken, pressing the need for development of algorithms that can analyze the contributions of different noise sources when a noise measurement is available. This paper addresses the cocktail-party problem inside integrated circuits with multiple noise sources. It presents a method to extract the time characteristics of individual noise source from the measured compound voltage in order to study the contribution and properties of each source. This extraction is facilitated by application of blind source separation technique, which is based on the assumption of statistical independence of various noise sources over time. The estimated noise sources can aid in performing timing and spectral analysis, and yield better circuit design techniques.  相似文献   

13.
陈寿齐  沈越泓  许魁 《信号处理》2010,26(1):141-145
现有的盲源分离算法往往利用信号某一方面的统计特性来分离信号,例如:利用信号的非高斯特性,或者利用信号的时序特性。在实际应用中,信号往往是具有这两种特性信号的混合,采用信号某一方面的特性往往不能够成功的分离出信号。现有的盲源分离算法往往不考虑噪声的影响,但在实际应用中,噪声的影响是不可避免的。当源信号具有非高斯性和非线性自相关特性时,提出了联合非高斯性和非线性自相关特性的有噪盲源分离算法。计算机仿真表明了提出算法的有效性,和现有的基于非高斯性和非线性自相关特性的有噪盲源分离算法相比,提出算法具有更好的信号分离性能。   相似文献   

14.
This paper addresses the problem of blind separation of cyclostationary sources. By using the cyclostationarity property of the source signals, new criteria based on second-order cyclic statistics (SOCS) are established, from which two algorithms for blind source separation are proposed. Compared with the existing higher-order statistics-based approaches, our new approach requires few data samples and does not impose any restrictions on the probability distributions of the source signals. Simulation results are given to demonstrate the effectiveness of this new approach.  相似文献   

15.
This paper studies the problem of blind separation of convolutively mixed source signals on the basis of the joint diagonalization (JD) of power spectral density matrices (PSDMs) observed at the output of the separation system. Firstly, a general framework of JD-based blind source separation (BSS) is reviewed and summarized. Special emphasis is put on the separability conditions of sources and mixing system. Secondly, the JD-based BSS is generalized to the separation of convolutive mixtures. The definition of a time and frequency dependent characteristic matrix of sources allows us to state the conditions under which the separation of convolutive mixtures is possible. Lastly, a frequency-domain approach is proposed for convolutive mixture separation. The proposed approach exploits objective functions based on a set of PSDMs. These objective functions are defined in the frequency domain, but are jointly optimized with respect to the time-domain coefficients of the unmixing system. The local permutation ambiguity problems, which are inherent to most frequency-domain approaches, are effectively avoided with the proposed algorithm. Simulation results show that the proposed algorithm is valid for the separation of both simulated and real-word recorded convolutive mixtures.  相似文献   

16.
In this paper a novel algorithm based on subspace projections is developed for the blind kernel identification of LTI FIR multiple input multiple output (MIMO) systems, as well as blind equalization of finite memory SIMO Volterra systems. In addition, for Volterra systems, the algorithm computes the memory lengths of the nonlinearities involved. Simulations in the context of blind channel equalization and identification demonstrate good performance in comparison to existing schemes.  相似文献   

17.
提出了单通道下基于盲源分离的扩频通信抗干扰方法.所提方法利用扩频序列的周期性,把单通道下的欠定盲源分离问题转换成超定盲源分离问题.算法从整体域统计特性对于扰信号进行估计抵消,同时在抗干扰的过程中完成了解扩.从原理上讲,这种抗干扰方法比目前常用的单通道下基于局部域特性的抗干扰方法具有更好的性能.理论分析和仿真结果表明了算法的有效性.  相似文献   

18.
In this paper a study of the cumulant-based blind equalization algorithms PAJOD and PAFA is conducted. Both algorithms assume that the data have been pre-whitened and hence the problem reduces to the estimation of paraunitary channels. The main contribution of this paper is an efficient implementation of the PAJOD algorithm called PAJOD2. Second, a performance comparison between the PAJOD, PAJOD2 and PAFA algorithms is reported.  相似文献   

19.
一种基于盲源分离的雷达抗干扰技术   总被引:5,自引:0,他引:5  
如何提高雷达的抗干扰能力一直是雷达信号处理的一大问题,问题的解决可以使雷达的检测和跟踪能力得以提高。在日趋复杂的信号环境下,传统的信号处理方法的局限性愈来愈大。本文通过对雷达信号处理过程和盲源分离技术的分析研究,提出采用基于盲源分离的多步处理抗干扰方法进行雷达抗干扰信号处理,可使雷达在复杂背景下具有更强的抗干扰能力。仿真试验结果证明这种新的雷达抗干扰处理方法是可行和令人满意的。  相似文献   

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