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arXiv 2409.06320cs.ITmath.IT
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亚线性稀疏度压缩感知的广义近似消息传递

Generalized Approximate Message-Passing for Compressed Sensing with Sublinear Sparsity

Keigo Takeuchi

AI总结:

针对亚线性稀疏度下的广义线性测量信号重建问题,提出基于状态演化的广义近似消息传递(GAMP)算法,推导其样本复杂度的重建阈值,数值模拟表明该算法在样本复杂度上优于现有算法。

摘要:

本文研究从广义线性测量中重建具有亚线性稀疏度的未知信号向量问题。通过亚线性稀疏度极限下的状态演化,提出广义近似消息传递(GAMP)算法,其中信号维度$N$、测量维度$M$和信号稀疏度$k$满足:当$N$和$k$趋于无穷时,$\frac{\text{log}k}{\text{log}N}\to\boldsymbol{\text{γ}}\boldsymbol{\text{∈}}\boldsymbol{\text{[0,1)}}$,且$\frac{M}{\boldsymbol{\text{k}}\text{log}(N/k)}\to\boldsymbol{\text{δ}}$。尽管状态演化的整体流程与线性稀疏度情况相同,但内部去噪的每个证明步骤需要比线性稀疏度更强的假设。本文证明了贝叶斯内部去噪满足所需的新假设。当GAMP使用贝叶斯外部和内部去噪器时,所得状态演化递归用于评估样本复杂度中的前置因子$\boldsymbol{\text{δ}}$(称为重建阈值)。当且仅当$\boldsymbol{\text{δ}}$大于重建阈值时,贝叶斯GAMP可实现渐近精确的信号重建。特别地,当非零信号元素的支持不包含零的邻域时,带噪线性测量的重建阈值是有限的。作为数值示例,本文考虑线性测量和1位压缩感知,两种情况的数值模拟均表明,在亚线性稀疏度下,贝叶斯GAMP在样本复杂度方面优于现有算法。

英文摘要:

This paper addresses the reconstruction of an unknown signal vector with sublinear sparsity from generalized linear measurements. Generalized approximate message-passing (GAMP) is proposed via state evolution in the sublinear sparsity limit, where the signal dimension $N$, measurement dimension $M$, and signal sparsity $k$ satisfy $\log k/\log N\to γ\in[0, 1)$ and $M/\{k\log (N/k)\}\toδ$ as $N$ and $k$ tend to infinity. While the overall flow in state evolution is the same as that for linear sparsity, each proof step for inner denoising requires stronger assumptions than those for linear sparsity. The required new assumptions are proved for Bayesian inner denoising. When Bayesian outer and inner denoisers are used in GAMP, the obtained state evolution recursion is utilized to evaluate the prefactor $δ$ in the sample complexity, called reconstruction threshold. If and only if $δ$ is larger than the reconstruction threshold, Bayesian GAMP can achieve asymptotically exact signal reconstruction. In particular, the reconstruction threshold is finite for noisy linear measurements when the support of non-zero signal elements does not include a neighborhood of zero. As numerical examples, this paper considers linear measurements and 1-bit compressed sensing. Numerical simulations for both cases show that Bayesian GAMP outperforms existing algorithms for sublinear sparsity in terms of the sample complexity.

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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