Gaussian and quadratic approximations of message passing algorithms on graphs
have attracted considerable recent attention due to their computational
simplicity, analytic tractability, and wide applicability in optimization and
statistical inference problems. This paper presents a systematic framework for
incorporating such approximate message passing (AMP) methods in general
graphical models.
This paper considers the problem of detecting the support (sparsity pattern)
of a sparse vector from random noisy measurements. Conditional power of a
component of the sparse vector is defined as the energy conditioned on the
component being nonzero. Analysis of a simplified version of orthogonal
matching pursuit (OMP) called sequential OMP (SequOMP) demonstrates the
importance of knowledge of the rankings of conditional powers.
We consider the optimal quantization of compressive sensing measurements
following the work on generalization of relaxed belief propagation (BP) for
arbitrary measurement channels. Relaxed BP is an iterative reconstruction
scheme inspired by message passing algorithms on bipartite graphs. Its
asymptotic error performance can be accurately predicted and tracked through
the state evolution formalism.
We consider a broad class of interference coordination and resource
allocation problems for wireless links where the goal is to maximize the sum of
functions of individual link rates. Such problems arise in the context of, for
example, fractional frequency reuse (FFR) for macro-cellular networks and
dynamic interference management in femtocells. The resulting optimization
problems are typically hard to solve optimally even using centralized
algorithms but are an essential computational step in implementing rate-fair
and queue stabilizing scheduling policies in wireless networks.
A significant technical challenge in deploying femtocells is controlling the
interference from the underlay of femtos onto the overlay of macros. This paper
presents a novel interference control method where the macrocell bandwidth is
partitioned into subbands, and the short-range femtocell links adaptively
allocate their power across the subbands based on a load-spillage power control
method. It is well-known that subband partitioning can be beneficial for the
macrocellular capacity.
We consider the general problem of estimating a random vector from
measurements generated by a linear transform followed by a componentwise
probabilistic measurement channel. We call this the linear mixing estimation
problem, since the linear transform couples the components of the input and
output vectors. The main contribution of this paper is a general algorithm
called linearized belief propagation (LBP) that iteratively "decouples" the
vector minimum mean-squared error (MMSE) estimation problem into a sequence of
componentwise scalar problems.
The replica method is a non-rigorous but widely-accepted technique from
statistical physics used in the asymptotic analysis of large, random, nonlinear
problems. This paper applies the replica method to non-Gaussian maximum a
posteriori (MAP) estimation. It is shown that with random linear measurements
and Gaussian noise, the asymptotic behavior of the MAP estimate of an
n-dimensional vector decouples as n scalar MAP estimators. The result is a
counterpart to Guo and Verdu's replica analysis of minimum mean-squared error
estimation.
The replica method is a non-rigorous but widely-accepted technique from
statistical physics used in the asymptotic analysis of large, random, nonlinear
problems. This paper applies the replica method to non-Gaussian maximum a
posteriori (MAP) estimation. It is shown that with random linear measurements
and Gaussian noise, the asymptotic behavior of the MAP estimate of an
n-dimensional vector decouples as n scalar MAP estimators. The result is a
counterpart to Guo and Verdu's replica analysis of minimum mean-squared error
estimation.