Title
Fixed points of generalized approximate message passing with arbitrary matrices
Abstract
The estimation of a random vector with independent components passed through a linear transform followed by a componentwise (possibly nonlinear) output map arises in a range of applications. Approximate message passing (AMP) methods, based on Gaussian approximations of loopy belief propagation, have recently attracted considerable attention for such problems. For large random transforms, these methods exhibit fast convergence and admit precise analytic characterizations with testable conditions for optimality, even for certain non-convex problem instances. However, the behavior of AMP under general transforms is not fully understood. In this paper, we consider the generalized AMP (GAMP) algorithm and relate the method to more common optimization techniques. This analysis enables a precise characterization of the GAMP algorithm fixed-points that applies to arbitrary transforms. In particular, we show that the fixed points of the so-called max-sum GAMP algorithm for MAP estimation are critical points of a constrained maximization of the posterior density. The fixed-points of the sum-product GAMP algorithm for estimation of the posterior marginals can be interpreted as critical points of a certain mean-field variational optimization.
Year
DOI
Venue
2013
10.1109/ISIT.2013.6620309
Information Theory Proceedings
Keywords
Field
DocType
Gaussian processes,approximation theory,convex programming,matrix algebra,message passing,AMP methods,GAMP algorithm,Gaussian approximations,arbitrary matrices,constrained maximization,fixed points,generalized AMP,generalized approximate message passing,independent components,linear transform,mean-field variational optimization,nonconvex problem,optimization techniques,output map,random vector estimation,ADMM,Belief propagation,message passing,variational optimization
Convergence (routing),Approximation algorithm,Combinatorics,Algorithm design,Matrix (mathematics),Computer science,Multivariate random variable,Fixed point,Message passing,Belief propagation
Conference
Volume
Issue
ISSN
62
12
2157-8095
Citations 
PageRank 
References 
12
0.58
36
Authors
5
Name
Order
Citations
PageRank
Sundeep Rangan13101163.90
P. Schniter2103561.42
Erwin Riegler315114.85
Alyson K. Fletcher455241.10
Volkan Cevher51860141.56