Beta–Beta Bounds: Finite-Blocklength Analog of the Golden Formula

It is well known that the mutual information between two random variables can be expressed as the difference of two relative entropies that depend on an auxiliary distribution, a relation sometimes referred to as the golden formula. This paper is concerned with a finite-blocklength extension of this...

Full description

Bibliographic Details
Main Authors: Yang, Wei, Collins, Austin Daniel, Durisi, Giuseppe, Polyanskiy, Yury, Poor, H. Vincent
Other Authors: Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Format: Article
Language:English
Published: Institute of Electrical and Electronics Engineers (IEEE) 2020
Online Access:https://hdl.handle.net/1721.1/124314
_version_ 1826205761647149056
author Yang, Wei
Collins, Austin Daniel
Durisi, Giuseppe
Polyanskiy, Yury
Poor, H. Vincent
author2 Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
author_facet Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Yang, Wei
Collins, Austin Daniel
Durisi, Giuseppe
Polyanskiy, Yury
Poor, H. Vincent
author_sort Yang, Wei
collection MIT
description It is well known that the mutual information between two random variables can be expressed as the difference of two relative entropies that depend on an auxiliary distribution, a relation sometimes referred to as the golden formula. This paper is concerned with a finite-blocklength extension of this relation. This extension consists of two elements: 1) a finite-blocklength channel-coding converse bound by Polyanskiy and Verdú, which involves the ratio of two Neyman-Pearson $\beta $ functions (beta-beta converse bound); and 2) a novel beta-beta channel-coding achievability bound, expressed again as the ratio of two Neyman-Pearson $\beta $ functions. To demonstrate the usefulness of this finite-blocklength extension of the golden formula, the beta-beta achievability and converse bounds are used to obtain a finite-blocklength extension of Verdú's wideband-slope approximation. The proof parallels the derivation of the latter, with the beta-beta bounds used in place of the golden formula. The beta-beta (achievability) bound is also shown to be useful in cases where the capacity-achieving output distribution is not a product distribution due to, e.g., a cost constraint or structural constraints on the codebook, such as orthogonality or constant composition. As an example, the bound is used to characterize the channel dispersion of the additive exponential-noise channel and to obtain a finite-blocklength achievability bound (the tightest to date) for multiple-input multiple-output Rayleigh-fading channels with perfect channel state information at the receiver.
first_indexed 2024-09-23T13:18:36Z
format Article
id mit-1721.1/124314
institution Massachusetts Institute of Technology
language English
last_indexed 2024-09-23T13:18:36Z
publishDate 2020
publisher Institute of Electrical and Electronics Engineers (IEEE)
record_format dspace
spelling mit-1721.1/1243142022-09-28T13:19:10Z Beta–Beta Bounds: Finite-Blocklength Analog of the Golden Formula Yang, Wei Collins, Austin Daniel Durisi, Giuseppe Polyanskiy, Yury Poor, H. Vincent Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science It is well known that the mutual information between two random variables can be expressed as the difference of two relative entropies that depend on an auxiliary distribution, a relation sometimes referred to as the golden formula. This paper is concerned with a finite-blocklength extension of this relation. This extension consists of two elements: 1) a finite-blocklength channel-coding converse bound by Polyanskiy and Verdú, which involves the ratio of two Neyman-Pearson $\beta $ functions (beta-beta converse bound); and 2) a novel beta-beta channel-coding achievability bound, expressed again as the ratio of two Neyman-Pearson $\beta $ functions. To demonstrate the usefulness of this finite-blocklength extension of the golden formula, the beta-beta achievability and converse bounds are used to obtain a finite-blocklength extension of Verdú's wideband-slope approximation. The proof parallels the derivation of the latter, with the beta-beta bounds used in place of the golden formula. The beta-beta (achievability) bound is also shown to be useful in cases where the capacity-achieving output distribution is not a product distribution due to, e.g., a cost constraint or structural constraints on the codebook, such as orthogonality or constant composition. As an example, the bound is used to characterize the channel dispersion of the additive exponential-noise channel and to obtain a finite-blocklength achievability bound (the tightest to date) for multiple-input multiple-output Rayleigh-fading channels with perfect channel state information at the receiver. National Science Foundation (10.13039/100000001) Swedish Research Council Center for Science of Information 2020-03-25T14:31:20Z 2020-03-25T14:31:20Z 2018-05 2019-07-01T17:44:24Z Article http://purl.org/eprint/type/JournalArticle 0018-9448 1557-9654 https://hdl.handle.net/1721.1/124314 Yang, Wei et al. "Beta–Beta Bounds: Finite-Blocklength Analog of the Golden Formula." IEEE Transactions on Information Theory 64, 9 (September 2018): 6236 - 6256 © 1963-2012 IEEE. en http://dx.doi.org/10.1109/tit.2018.2837104 IEEE Transactions on Information Theory Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Institute of Electrical and Electronics Engineers (IEEE) arXiv
spellingShingle Yang, Wei
Collins, Austin Daniel
Durisi, Giuseppe
Polyanskiy, Yury
Poor, H. Vincent
Beta–Beta Bounds: Finite-Blocklength Analog of the Golden Formula
title Beta–Beta Bounds: Finite-Blocklength Analog of the Golden Formula
title_full Beta–Beta Bounds: Finite-Blocklength Analog of the Golden Formula
title_fullStr Beta–Beta Bounds: Finite-Blocklength Analog of the Golden Formula
title_full_unstemmed Beta–Beta Bounds: Finite-Blocklength Analog of the Golden Formula
title_short Beta–Beta Bounds: Finite-Blocklength Analog of the Golden Formula
title_sort beta beta bounds finite blocklength analog of the golden formula
url https://hdl.handle.net/1721.1/124314
work_keys_str_mv AT yangwei betabetaboundsfiniteblocklengthanalogofthegoldenformula
AT collinsaustindaniel betabetaboundsfiniteblocklengthanalogofthegoldenformula
AT durisigiuseppe betabetaboundsfiniteblocklengthanalogofthegoldenformula
AT polyanskiyyury betabetaboundsfiniteblocklengthanalogofthegoldenformula
AT poorhvincent betabetaboundsfiniteblocklengthanalogofthegoldenformula