Non-negative Sparse Recovery at Minimal Sampling Rate
Hendrik Bernd Zarucha, Peter Jung
TL;DR
The paper addresses uniform, robust recovery of non-negative $S$-sparse signals from minimal measurements by introducing the signed kernel condition, a non-null-space criterion enabling polynomial-time recovery via the non-negative least residual. It establishes formal equivalences between robustness and recovery, and extends these results to real Vandermonde constructions and complex formulations, showing that $M=O(S)$ measurements suffice under the signed kernel condition. It connects the recovery guarantees to outwardly neighborly polytopes and provides practical constructions, including linear-programming-based decoding for real cases. A bound on the complexity constant reveals the trade-off between dimension, sparsity, and measurements, highlighting regimes where near-optimal sampling is feasible and regimes where robustness constants deteriorate with problem size. Overall, the work fills a longstanding gap by achieving uniform, robust non-negative recovery with minimal sampling and polynomial-time decoding in structured settings.
Abstract
It is known that sparse recovery is possible if the number of measurements is in the order of the sparsity, but the corresponding decoders either lack polynomial decoding time or robustness to noise. Commonly, decoders that rely on a null space property are being used. These achieve polynomial time decoding and are robust to additive noise but pay the price by requiring more measurements. The non-negative least residual has been established as such a decoder for non-negative recovery. A new equivalent condition for uniform, robust recovery of non-negative sparse vectors with the non-negative least residual that is not based on null space properties is introduced. It is shown that the number of measurements for this equivalent condition only needs to be in the order of the sparsity. Further, it is explained why the robustness to additive noise is similar, but not equal, to the robustness of decoders based on null space properties.
