2010/03/24 by David L. Donoho, Jared Tanner · 77 citations
Computer Science · Engineering · Mathematics · #Arithmetic #Combinatorics #Computer science #Discrete mathematics #Distributed Sensor Networks and Detection Algorithms #Emphasis (telecommunications) #Mathematics #Notation #Sparse and Compressive Sensing Techniques #Wireless Communication Security Techniques
paper · open access · doi:10.1109/tit.2010.2040892
published in IEEE Transactions on Information Theory 56(4), 2002-2016 (Institute of Electrical and Electronics Engineers)
openalex publication_date 2010/03/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
In“Counting faces of randomly projected polytopes when the projection radically lowers dimension”the authors proved an asymptoticsampling theorem for sparse signals, showing thatnrandom measurements permit to reconstruct anN-vector havingknonzeros providedn gt; 2 ⋅ k ⋅ log(N/n) (1+o(1))reconstruction usesℓ1minimization. They also proved anasymptotic rate theorem, showing existence of real error-correcting codes for messages of lengthNwhich can correct all possiblek-element error patterns using justngeneralized checksum bits, wheren gt; 2e⋅ k log(N/n) (1 + o(1))decoding usesℓ1minimization. Both results require an asymptotic framework, withNgrowing large. For applications, on the other hand, we are concerned with specific triplesk, n, N. We exhibit triples(k,n,N)for which Compressed Sensing Matrices and Real Error-Correcting Codes surely exist and can be obtained with high probability by random sampling. These derive from exponential bounds on the probability of drawing ‘bad’ matrices. The bounds give conditions effective at finite-N, and converging to the known sharp asymptotic conditions for largeN. Compared to other finite-Nbounds known to us, they are much stronger, and much more explicit. Our bounds derive from asymptotics in“Counting faces of randomly projected polytopes when the projection radically lowers dimension”counting the expected number ofk-dimensional faces of the randomly projected simplexTN-1and cross-polytopeCN. We develop here finite-Nbounds on the expected discrepancy between the number ofk-faces of the projected polytopeAQand its generatorQ, forQ=TN-1andCN. Our bounds also imply existence of interesting geometric objects. Thus, we exhibit triples(k,n,N)for which polytopes with2Nvertices can be centrallyk-neighborly.