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arXiv 2109.14079cs.ITcs.NAmath.ITmath.NAstat.CO
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基于随机动态采样的带限图信号鲁棒恢复

Robust recovery of bandlimited graph signals via randomized dynamical sampling

Longxiu Huang, Deanna Needell, Sui Tang

摘要:

热扩散过程在图上的动力系统建模中有着广泛的应用。在本文中,我们考虑恢复的$k$ -带限图信号,这是一个初始信号的热扩散过程从其时空样本。我们提出了三个随机时空采样制度,称为动态采样技术,包括在随机选择一个小的时空节点的子集,根据一些概率分布。我们表明,所需的空间-时间样本的数量,以确保稳定的恢复每个政权取决于一个参数称为谱图加权相干性,这取决于动态之间的相互作用,在图形和采样概率分布。在最佳情况下,不超过$\mathcal{O}(k \log(k))$空时样本足以确保所有$k$带限信号的准确和稳定恢复。在任何情况下,通过利用时间信息,动态采样通常需要比静态情况少得多的空间样本。然后,我们提出了一种计算效率高的方法来重建$k$带限信号从他们的空时样本。我们证明,它产生准确的重建,它也是稳定的噪声。最后,我们测试各种各样的图形上的动态采样技术。数值结果支持我们的理论研究结果,并证明了效率。

英文摘要:

Heat diffusion processes have found wide applications in modelling dynamical systems over graphs. In this paper, we consider the recovery of a $k$-bandlimited graph signal that is an initial signal of a heat diffusion process from its space-time samples. We propose three random space-time sampling regimes, termed dynamical sampling techniques, that consist in selecting a small subset of space-time nodes at random according to some probability distribution. We show that the number of space-time samples required to ensure stable recovery for each regime depends on a parameter called the spectral graph weighted coherence, that depends on the interplay between the dynamics over the graphs and sampling probability distributions. In optimal scenarios, no more than $\mathcal{O}(k \log(k))$ space-time samples are sufficient to ensure accurate and stable recovery of all $k$-bandlimited signals. In any case, dynamical sampling typically requires much fewer spatial samples than the static case by leveraging the temporal information. Then, we propose a computationally efficient method to reconstruct $k$-bandlimited signals from their space-time samples. We prove that it yields accurate reconstructions and that it is also stable to noise. Finally, we test dynamical sampling techniques on a wide variety of graphs. The numerical results support our theoretical findings and demonstrate the efficiency.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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