{ "id": "1707.04413", "version": "v1", "published": "2017-07-14T08:37:50.000Z", "updated": "2017-07-14T08:37:50.000Z", "title": "The Mutual information of LDGM codes", "authors": [ "Jan van den Brand", "Nor Jaafari" ], "categories": [ "cs.IT", "math.IT", "math.PR" ], "abstract": "We provide matching upper and lower bounds on the mutual information in noisy reconstruction of parity check codes and thereby prove a long-standing conjecture by Montanari [IEEE Transactions on Information Theory 2005]. Besides extending a prior concentration result of Abbe and Montanari [Theory of Computing 2015] to the case of odd check degrees, we precisely determine the conjectured formula for code ensembles of arbitrary degree distribution, thus capturing a broad class of capacity approaching codes.", "revisions": [ { "version": "v1", "updated": "2017-07-14T08:37:50.000Z" } ], "analyses": { "subjects": [ "94A17", "68Q87" ], "keywords": [ "mutual information", "ldgm codes", "prior concentration result", "odd check degrees", "arbitrary degree distribution" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }