Error Exponents and <i>α</i>-Mutual Information

Over the last six decades, the representation of error exponent functions for data transmission through noisy channels at rates below capacity has seen three distinct approaches: (1) Through Gallager’s <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="...

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Main Author: Sergio Verdú
Format: Article
Language:English
Published: MDPI AG 2021-02-01
Series:Entropy
Subjects:
Online Access:https://www.mdpi.com/1099-4300/23/2/199
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author Sergio Verdú
author_facet Sergio Verdú
author_sort Sergio Verdú
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description Over the last six decades, the representation of error exponent functions for data transmission through noisy channels at rates below capacity has seen three distinct approaches: (1) Through Gallager’s <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>E</mi><mn>0</mn></msub></semantics></math></inline-formula> functions (with and without cost constraints); (2) large deviations form, in terms of conditional relative entropy and mutual information; (3) through the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula>-mutual information and the Augustin–Csiszár mutual information of order <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> derived from the Rényi divergence. While a fairly complete picture has emerged in the absence of cost constraints, there have remained gaps in the interrelationships between the three approaches in the general case of cost-constrained encoding. Furthermore, no systematic approach has been proposed to solve the attendant optimization problems by exploiting the specific structure of the information functions. This paper closes those gaps and proposes a simple method to maximize Augustin–Csiszár mutual information of order <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> under cost constraints by means of the maximization of the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula>-mutual information subject to an exponential average constraint.
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spelling doaj.art-71b3ba253e7c49ddb39bda170121c5022023-12-03T12:36:57ZengMDPI AGEntropy1099-43002021-02-0123219910.3390/e23020199Error Exponents and <i>α</i>-Mutual InformationSergio Verdú0Independent Researcher, Princeton, NJ 08540, USAOver the last six decades, the representation of error exponent functions for data transmission through noisy channels at rates below capacity has seen three distinct approaches: (1) Through Gallager’s <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>E</mi><mn>0</mn></msub></semantics></math></inline-formula> functions (with and without cost constraints); (2) large deviations form, in terms of conditional relative entropy and mutual information; (3) through the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula>-mutual information and the Augustin–Csiszár mutual information of order <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> derived from the Rényi divergence. While a fairly complete picture has emerged in the absence of cost constraints, there have remained gaps in the interrelationships between the three approaches in the general case of cost-constrained encoding. Furthermore, no systematic approach has been proposed to solve the attendant optimization problems by exploiting the specific structure of the information functions. This paper closes those gaps and proposes a simple method to maximize Augustin–Csiszár mutual information of order <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> under cost constraints by means of the maximization of the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula>-mutual information subject to an exponential average constraint.https://www.mdpi.com/1099-4300/23/2/199information measuresrelative entropyRényi divergencemutual informationα-mutual informationAugustin–Csiszár mutual information
spellingShingle Sergio Verdú
Error Exponents and <i>α</i>-Mutual Information
Entropy
information measures
relative entropy
Rényi divergence
mutual information
α-mutual information
Augustin–Csiszár mutual information
title Error Exponents and <i>α</i>-Mutual Information
title_full Error Exponents and <i>α</i>-Mutual Information
title_fullStr Error Exponents and <i>α</i>-Mutual Information
title_full_unstemmed Error Exponents and <i>α</i>-Mutual Information
title_short Error Exponents and <i>α</i>-Mutual Information
title_sort error exponents and i α i mutual information
topic information measures
relative entropy
Rényi divergence
mutual information
α-mutual information
Augustin–Csiszár mutual information
url https://www.mdpi.com/1099-4300/23/2/199
work_keys_str_mv AT sergioverdu errorexponentsandiaimutualinformation