Title
Capacity of the Vector Gaussian Channel in the Small Amplitude Regime
Abstract
This paper studies the capacity of an n-dimensional vector Gaussian noise channel subject to the constraint that an input must lie in the ball of radius R centered at the origin. It is known that in this setting the optimizing input distribution is supported on a finite number of concentric spheres. However, the number, the positions and the probabilities of the spheres are generally unknown. This paper characterizes necessary and sufficient conditions on the constraint R such that the input distribution supported on a single sphere is optimal. The maximum $\overline{R}_{n}$, such that using only a single sphere is optimal, is shown to be a solution of an integral equation. Moreover, it is shown that $\overline{R}_{n}$ scales as $\sqrt{n}$ and the exact limit of $\overline{R}_{n}\overline{\sqrt{n}}$ is found.
Year
DOI
Venue
2018
10.1109/ITW.2018.8613508
2018 IEEE Information Theory Workshop (ITW)
Keywords
Field
DocType
integral equation,vector Gaussian channel,single sphere,concentric spheres,finite number,optimizing input distribution,n-dimensional vector Gaussian noise channel subject
Discrete mathematics,Finite set,Concentric,Computer science,Upper and lower bounds,Integral equation,SPHERES,Gaussian noise,Channel capacity,Amplitude
Conference
ISSN
ISBN
Citations 
2475-420X
978-1-5386-3600-8
0
PageRank 
References 
Authors
0.34
0
3
Name
Order
Citations
PageRank
Alex Dytso14520.03
H. V. Poor2254111951.66
Shlomo Shamai Shitz333.14