Geometry and Symmetry in Short-and-Sparse Deconvolution

Geometry and Symmetry in Short-and-Sparse Deconvolution
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DOI:
10.1137/19m1237569
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发表时间:
2019-01
期刊:
ArXiv
影响因子:
--
通讯作者:
Han-Wen Kuo;Yenson Lau;Yuqian Zhang;John Wright
Han-Wen Kuo;Yenson Lau;Yuqian Zhang;John Wright
中科院分区:
其他
文献类型:
--
作者:
Han-Wen Kuo;Yenson Lau;Yuqian Zhang;John Wright

文献摘要

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我们研究从卷积中恢复短信号$\mathbf a_0$和稀疏信号$\mathbf x_0$的$\textit{短且稀疏(SaS)反卷积}$问题。我们提出一种基于非凸优化的方法,该方法在某些条件下能够恢复目标短信号和稀疏信号,但存在此模型固有的符号移位对称性。这种对称性在塑造反卷积的优化格局中起着核心作用。我们给出一种$\textit{区域分析}$,它在子空间的并集上从几何角度描述了这种格局。当长度为$p_0$的短信号$\mathbf a_0$具有移位相干性$\mu$,且$\mathbf x_0$遵循稀疏率为$\theta \in \Bigl[\frac{c_1}{p_0}, \frac{c_2}{p_0\sqrt\mu + \sqrt{p_0}}\Bigr]\cdot\frac{1}{\log^2p_0}$的随机稀疏模型时,我们的几何特征成立。基于这种几何结构,我们给出一种可证明的方法,该方法大概率能成功解决SaS反卷积问题。
We study the $\textit{Short-and-Sparse (SaS) deconvolution}$ problem of recovering a short signal $\mathbf a_0$ and a sparse signal $\mathbf x_0$ from their convolution. We propose a method based on nonconvex optimization, which under certain conditions recovers the target short and sparse signals, up to a signed shift symmetry which is intrinsic to this model. This symmetry plays a central role in shaping the optimization landscape for deconvolution. We give a $\textit{regional analysis}$, which characterizes this landscape geometrically, on a union of subspaces. Our geometric characterization holds when the length-$p_0$ short signal $\mathbf a_0$ has shift coherence $\mu$, and $\mathbf x_0$ follows a random sparsity model with sparsity rate $\theta \in \Bigl[\frac{c_1}{p_0}, \frac{c_2}{p_0\sqrt\mu + \sqrt{p_0}}\Bigr]\cdot\frac{1}{\log^2p_0}$. Based on this geometry, we give a provable method that successfully solves SaS deconvolution with high probability.