Summary
2020
Session Number:B09
Session:
Number:B09-1
A Simple Capacity Outer Bound for Two-Way Channels and Capacity Approximation Results
Jian-Jia Weng, Fady Alajaji, Tamas Linder,
pp.324-328
Publication Date:2020/10/18
Online ISSN:2188-5079
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Summary:
Channel symmetry properties that imply the tightness of Shannon's random coding inner bound have recently been used to determine the capacity region of discrete-memoryless two-way channels (DM-TWCs). For channels without such symmetry properties, outer bounds are often needed to estimate the capacity region. However, validating symmetry conditions and/or evaluating non-trivial outer bounds are computationally demanding, especially for channels with large input and output alphabets. In this paper, three easy-to-check conditions that identify DM-TWCs with no such symmetry properties as well as an easy-to-compute outer bound are derived. The bound is obtained from Shannon's inner bound computation but is non-trivial. Using this outer bound, approximate capacity results can be established for certain DM-TWCs. The results are illustrated by two examples.