Sparse Representation of White Gaussian Noise with Application to `0-Norm Decoding in Noisy Compressed Sensing

Abstract—The achievable and converse regions for sparse representation of white Gaussian noise based on an overcomplete dictionary are derived in the limit of large systems. Furthermore, the marginal distribution of such sparse representations is also inferred. The results are obtained via the Replica method which stems from statistical mechanics. A direct outcome of these results is the introduction of sharp threshold for `0-norm decoding in noisy compressed sensing, and its mean-square error for underdetermined Gaussian vector channels. I