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 |
|---|---|
| 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)