Achievable rate regions of multi‐way relay channel with direct links. Issue 7 (1st May 2015)

• Record Type: Journal Article
• Authors: Su, Yuping; Li, Ying; Song, Guanghui; Liu, Lei
• Is Part Of: IET communications. Volume 9:Issue 7(2015)
• Page Start: 947
• Page End: 959
• Publication Date: 2015-05-01
• Subjects: relay networks (telecommunication) -- decode and forward communication -- wireless channels -- Gaussian processes -- set theory -- multi‐access systems; achievable rate regions -- multiway relay channel -- direct links -- Gaussian MWRC‐DL -- message exchange -- relay terminal -- cut‐set outer bound -- capacity region -- decode‐and‐forward strategy -- compress‐and‐forward strategy -- multiple‐access relay channel -- symmetric Gaussian network; Telecommunication systems -- Periodicals; Speech processing systems -- Periodicals; 621.38205
• DOI: 10.1049/iet-com.2014.0622
• Languages: English
• ISSNs: 1751-8628

Abstract

Abstract : Rate regions of a multi‐way relay channel with direct links (MWRC‐DLs), where K users exchange their messages via a relay terminal and all users can overhear each other directly, are studied in this study. Under the assumption that a restricted encoder is employed at each user, the cut‐set outer bound on the capacity region is derived first. Then, achievable rate regions of the MWRC‐DLs with decode‐and‐forward (DF) and compress‐and‐forward (CF) strategies are characterised. Meanwhile, the explicit expressions of the outer bound and the achievable rate regions for the Gaussian MWRC‐DLs are also derived. It is shown that the rate regions of the DF and CF strategies for the two‐way relay channel and the multiple‐access relay channel can be obtained from those of the MWRC‐DLs. To give more insights on the two strategies of the MWRC‐DLs system, the common rates of a symmetric Gaussian network are analysed. It is shown that the CF strategy achieves common rates within 1/2( K − 1) bits of the capacity when the relay's power is at least ( K − 1) times as large as the user power. Numerical examples are also provided to verify the theoretical analysis.