Abstract
For any channel P Y|X the strong data processing constant is defined as the smallest number η KL\in [0,1] such that I(U;Y)\≤ η KL I(U;X) holds for any Markov chain U-X-Y. It is shown that the value of η KL is given by that of the best binary-input subchannel of P Y|X. The same result holds for any f-divergence, verifying a conjecture of Cohen, Kemperman and Zbaganu (1998).
Original language | English |
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Pages (from-to) | 1480-1481 |
Number of pages | 2 |
Journal | IEEE Transactions on Information Theory |
Volume | 68 |
Issue number | 3 |
DOIs | |
State | Published - 1 Mar 2022 |
Bibliographical note
Publisher Copyright:© 1963-2012 IEEE.
Keywords
- Contraction coefficient
- F-divergence
- Strong data processing inequality (SDPI)