ΒιΆΉ΄«Γ½Σ³»­

Multiple Support Recovery Using Very Few Measurements Per Sample
Lekshmi Ramesh Chandra R. Murthy Himanshu Tyagi
Proceedings of the 2021 ΒιΆΉ΄«Γ½Σ³»­ International Symposium on Information Theory, Melbourne, Australia, July 2021
Abstract

In the problem of multiple support recovery, we are given access to linear measurements of multiple sparse samples in ℝ^d. These samples can be partitioned into β„“ groups, with samples having the same support belonging to the same group. For a given budget of m measurements per sample, the goal is to recover the β„“ underlying supports, in the absence of the knowledge of group labels. We study this problem with a focus on the measurement-constrained regime where m is smaller than the support size k of each sample. We design a two-step procedure thatΒ estimatesΒ the union of the underlying supports first, and then uses a spectral algorithm to estimate the individual supports. Our proposed estimator can recover the supports with m<k measurements per sample, from Γ•(k^4β„“^4/m^4) samples. Our guarantees hold for a general, generative model assumption on the samples and measurement matrices. We also provide results from experiments conducted on synthetic data and on theΒ MNIST dataset.