共查询到20条相似文献,搜索用时 15 毫秒
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We have shown previously that non-stationary signals recorded in a static multi-path environment can often be recovered by simultaneously decorrelating varying second order statistics. As typical sources are often moving, however, the multi-path channel is not static. We present here an on-line gradient algorithm with adaptive step size in the frequency domain based on second derivatives, which we refer to as multiple adaptive decorrelation (MAD). We compared the separation performance of the proposed algorithm to its off-line counterpart and to another decorrelation based on-line algorithm. 相似文献
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This paper considers mixing matrix estimation for underdetermined blind source separation. First, we propose an effective detection algorithm to identify single source points where only one source occurs. The detection algorithm finds single source points by utilizing the time–frequency coefficients of mixed signals and the complex conjugates of the coefficients. Then, a method based on probability density is proposed in order to find more reliable single source points and cluster them. Finally, the mixing matrix is obtained through re-selecting and clustering single source points. The experimental results indicate that the algorithm can accurately estimate the mixing matrix when there are fewer sensors than sources. 相似文献
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Frdric Vrins Dinh-Tuan Pham Michel Verleysen 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2007,53(3):1030-1042
In this paper, both non-mixing and mixing local minima of the entropy are analyzed from the viewpoint of blind source separation (BSS); they correspond respectively to acceptable and spurious solutions of the BSS problem. The contribution of this work is twofold. First, a Taylor development is used to show that the exact output entropy cost function has a non-mixing minimum when this output is proportional to any of the non-Gaussian sources, and not only when the output is proportional to the lowest entropic source. Second, in order to prove that mixing entropy minima exist when the source densities are strongly multimodal, an entropy approximator is proposed. The latter has the major advantage that an error bound can be provided. Even if this approximator (and the associated bound) is used here in the BSS context, it can be applied for estimating the entropy of any random variable with multimodal density 相似文献
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混合语音信号的盲分离 总被引:1,自引:0,他引:1
重点研究了卷积混合语音信号的盲分离方法。语音信号是非平稳信号,但是它在短时间上具有平稳性。因此,本文对语音信号进行加窗傅立叶变换(FFT)将卷积混合问题转换为频域上每个频点的瞬时性BSS(blind source separation)问题,采用定点(fixed—point)ICA(independent component analysis)算法对混合语音信号进行了分离,并用matlab进行了仿真。 相似文献
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一种信号源盲分离的神经网络算法 总被引:6,自引:0,他引:6
本文提出了一种新的盲信号分离的神经网络算法。神经网络的第一层使用奇异值分解(SVD)方法对观测信号进行预白化处理。在传感器的数目不少于源信号的情况下,预白化处理能够估计出源信号的数目,同时压缩掉冗余信息。神经网络的第二层是分离层。分离层的权值矩阵应该是正交矩阵。本文应用一个正交严格受限(SOC)算法调整分离网络的权值。其中,用恢复信号的四阶互累积量的平方构造代价函数。仿真实验验证了算法的有效性。 相似文献
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针对盲源分离问题,提出一种基于接收信号不同延时下自相关矩阵组的快速联合对角化算法(FJD).采用乘性迭代机制求解表征联合对角化近似程度的F-范数代价函数.对代价函数的合理近似及巧妙求解,是算法快速有效的核心原因.每步迭代得到的严格对角占优更新矩阵,保证联合对角化器严格可逆,防止收敛到平凡解.算法具有不需要预白化操作,不限定待对角化目标矩阵的正定性,并能处理复值数据等诸多优点,具有极广的适用性.详细的计算复杂度分析说明了算法的高效性及易操作性.仿真结果表明,FJD算法收敛速度快,性能良好,能有效地解决盲源分离问题. 相似文献
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传感器采集到的信号是由多目标源、环境噪声等经多途径卷积混合的形武.为有效地去除环境因素如干扰、传输延迟等的影响,提出一种新的盲信号分离方法.利用非平稳信号的多重去相关和最小二乘准则来估计混合矩阵A或解混矩阵W以及信号和噪声功率.实验结果表明,该算法具有良好的分离效果. 相似文献
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将秩一非负矩阵分解应用于盲源分离问题,把基于欧式距离的目标函数转化成二次函数的形式;施加稀疏性约束和正交性约束保证信号可分离性;利用二次函数的性质分别推得混合矩阵和源信号的迭代公式,从而得到一种基于秩一分解的快速NMF盲源分离算法(NMF-R1)。分析得到一次迭代更新NMF-R1算法比传统NMF盲源分离算法(NMF-BM)所需乘法次数少约30%,NMF-R1算法无矩阵求逆运算,NMF-BM算法还需2次矩阵求逆运算。图像信号的超定和欠定盲源分离仿真结果表明,NMF-R1算法都能分离出源信号, NMF-BM算法只能分离超定混合信号;NMF-R1算法与NMF-BM算法比,分离性能好、收敛速度快。 相似文献
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一种新的瞬时混迭信号盲分离的自适应方法 总被引:1,自引:0,他引:1
本文利用源信号的统计独立特性,推导出一种瞬时混迭信号分离的自适应方法,这种方法将预白化和正交化合二为一,仅利用观测数据迭代更新分离阵参数。计算机仿真实验结果表明,该方法是有效的,可以较精确分离线性混迭的信号。 相似文献
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自然梯度盲源分离算法通常采用固定步长,但这样做会造成算法收敛速度慢和跟踪能力差.为此,提出了一种新的自然梯度自适应步长盲源分离算法,使步长在每次迭代中根据其他参数的变化做出相应的调整.在非稳态环境下,计算机仿真试验结果表明,新算法不仅具有良好盲分离性能,而且在上述两个方面都有了较大改善. 相似文献
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盲源分离是一种多通道的信号处理方法。应用盲源分离理论,可以在不知道传输通道的情况下,仅依靠采集到的信号,提取出各种源信号。构建累积量联合矩阵,进行对角化处理,得到分离矩阵,是一种很常见的盲源分离方法。针对通常算法精度不高的问题,提出了一种将基于二阶累积量和基于四阶累积量综合在一起的盲源分离算法。该方法结合了两种方法的优点,既考虑了二阶时空间上的不相关,又考虑了四阶累积量度量的独立性。 相似文献