On Channel Inseparability and the DoF Region of MIMO Multi-way Relay Channels
Conference: SCC 2015 - 10th International ITG Conference on Systems, Communications and Coding
02/02/2015 - 02/05/2015 at Hamburg, Germany
Pages: 6Language: englishTyp: PDFPersonal VDE Members are entitled to a 10% discount on this title
Chaaban, Anas; Sezgin, Aydin (Institute of Digital Communication Systems, Ruhr-Universität Bochum (RUB), Germany)
Full-duplex multi-way relaying is a potential solution for supporting high data rates in future Internet-of-Things (IoT) and 5G networks. Thus, in this paper the full-duplex MIMO multi-way channel consisting of 3 users (Y-channel) with M antennas each and a common relay node with N antennas is studied. Each user wants to exchange messages with all the other users via the relay. A transmission strategy is proposed based on channel diagonalization that decomposes the channel into parallel sub-channels, and physical-layer network coding over these subchannels. It is shown that the proposed strategy achieves the optimal DoF region of the channel if N = M. Furthermore, the proposed strategy that requires joint encoding over multiple sub-channels is compared to another strategy that encodes over each sub-channel separately. It turns out that coding jointly over sub-channels is necessary for an optimal transmission strategy. This shows that the MIMO Y-channel is inseparable.