2020/04/08 by Jian-Jian Weng, Jian-Jia Weng, Fady Alajaji +4
Computer Science · Engineering · Mathematics · #Cellular Automata and Applications #Cooperative Communication and Network Coding #FOS: Computer and information sciences #Information Theory (cs.IT) #Wireless Communication Security Techniques #cs.IT #math.IT
paper · pdf · doi:10.48550/arxiv.2004.03954
an error in Eq. (2) corrected
openalex publication_date 2020/04/08 · openalex created_date 2020/04/17 · arxiv created 2020/09/24 · arxiv updated 2020/09/28 · openalex updated_date 2026/07/28
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.