Abstract
The capacity of finite-state channels (FSCs) with feedback is considered. We derive a simple upper bound on the feedback capacity. The upper bound is based on an extension of the known duality upper bound on mutual information to the case of directed information. The upper bound is a function of test distributions on the channel outputs ensemble. We show that if the test distribution is structured on a Q-graph, and the FSC is unifilar, the upper bound can be formulated as a Markov decision process (MDP). The resulted MDP has finite states, actions and disturbances and, therefore, can be solved analytically with standard MDP tools. We illustrate the simplicity of computing the bounds for the dicode erasure and the Ising channels. The resulted upper bounds are tight and their derivation serves as an alternative and simple converse proof. The developed methodology is capable of solving channels with large alphabets of the channel states, inputs and outputs.
Original language | English |
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Title of host publication | International Zurich Seminar on Information and Communication (IZS 2020). Proceedings |
Editors | Amos Lapidoth, Stefan M. Moser |
Place of Publication | Zurich |
Publisher | ETH Zurich |
Pages | 68 - 72 |
DOIs | |
State | Published - 26 Feb 2020 |
Event | International Zurich Seminar on Information and Communication 2020 - Zurich, Switzerland Duration: 26 Feb 2020 → 28 Feb 2020 https://www.izs.ethz.ch/2020/ |
Conference
Conference | International Zurich Seminar on Information and Communication 2020 |
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Abbreviated title | IZS 2020 |
Country/Territory | Switzerland |
City | Zurich |
Period | 26/02/20 → 28/02/20 |
Internet address |