Optimal recovery from compressive measurements via denoising-based approximate message passing

Recently progress has been made in compressive sensing by replacing simplistic sparsity models with more powerful denoisers. In this paper, we develop a framework to predict the performance of denoising-based signal recovery algorithms based on a new deterministic state evolution formalism for approximate message passing. We compare our deterministic state evolution against its more classical Bayesian counterpart. We demonstrate that, while the two state evolutions are very similar, the deterministic framework is far more flexible. We apply the deterministic state evolution to explore the optimality of denoising-based approximate message passing (D-AMP). We prove that, while D-AMP is suboptimal for certain classes of signals, no algorithm can uniformly outperform it.