An Integral Representation of the Logarithmic Function with Applications in Information Theory

We explore a well-known integral representation of the logarithmic function, and demonstrate its usefulness in obtaining compact, easily computable exact formulas for quantities that involve expectations and higher moments of the logarithm of a positive random variable (or the logarithm of a sum of...

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Main Authors: Neri Merhav, Igal Sason
Format: Article
Language:English
Published: MDPI AG 2019-12-01
Series:Entropy
Subjects:
Online Access:https://www.mdpi.com/1099-4300/22/1/51
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author Neri Merhav
Igal Sason
author_facet Neri Merhav
Igal Sason
author_sort Neri Merhav
collection DOAJ
description We explore a well-known integral representation of the logarithmic function, and demonstrate its usefulness in obtaining compact, easily computable exact formulas for quantities that involve expectations and higher moments of the logarithm of a positive random variable (or the logarithm of a sum of i.i.d. positive random variables). The integral representation of the logarithm is proved useful in a variety of information-theoretic applications, including universal lossless data compression, entropy and differential entropy evaluations, and the calculation of the ergodic capacity of the single-input, multiple-output (SIMO) Gaussian channel with random parameters (known to both transmitter and receiver). This integral representation and its variants are anticipated to serve as a useful tool in additional applications, as a rigorous alternative to the popular (but non-rigorous) replica method (at least in some situations).
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spelling doaj.art-7f77094e86c5473b8a2b149fb0b2463d2022-12-22T02:20:29ZengMDPI AGEntropy1099-43002019-12-012215110.3390/e22010051e22010051An Integral Representation of the Logarithmic Function with Applications in Information TheoryNeri Merhav0Igal Sason1The Andrew and Erna Viterbi Faculty of Electrical Engineering, Israel Institute of Technology Technion City, Haifa 3200003, IsraelThe Andrew and Erna Viterbi Faculty of Electrical Engineering, Israel Institute of Technology Technion City, Haifa 3200003, IsraelWe explore a well-known integral representation of the logarithmic function, and demonstrate its usefulness in obtaining compact, easily computable exact formulas for quantities that involve expectations and higher moments of the logarithm of a positive random variable (or the logarithm of a sum of i.i.d. positive random variables). The integral representation of the logarithm is proved useful in a variety of information-theoretic applications, including universal lossless data compression, entropy and differential entropy evaluations, and the calculation of the ergodic capacity of the single-input, multiple-output (SIMO) Gaussian channel with random parameters (known to both transmitter and receiver). This integral representation and its variants are anticipated to serve as a useful tool in additional applications, as a rigorous alternative to the popular (but non-rigorous) replica method (at least in some situations).https://www.mdpi.com/1099-4300/22/1/51integral representationlogarithmic expectationuniversal data compressionentropydifferential entropyergodic capacitysimo channelmultivariate cauchy distribution
spellingShingle Neri Merhav
Igal Sason
An Integral Representation of the Logarithmic Function with Applications in Information Theory
Entropy
integral representation
logarithmic expectation
universal data compression
entropy
differential entropy
ergodic capacity
simo channel
multivariate cauchy distribution
title An Integral Representation of the Logarithmic Function with Applications in Information Theory
title_full An Integral Representation of the Logarithmic Function with Applications in Information Theory
title_fullStr An Integral Representation of the Logarithmic Function with Applications in Information Theory
title_full_unstemmed An Integral Representation of the Logarithmic Function with Applications in Information Theory
title_short An Integral Representation of the Logarithmic Function with Applications in Information Theory
title_sort integral representation of the logarithmic function with applications in information theory
topic integral representation
logarithmic expectation
universal data compression
entropy
differential entropy
ergodic capacity
simo channel
multivariate cauchy distribution
url https://www.mdpi.com/1099-4300/22/1/51
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