Hybrid Full-Duplex and Alternate Multiple Relay Selection and Beamforming in AF Cooperative Networks

In this paper, multiple relay selection and beamforming techniques are applied to a dual-hop full-duplex (FD) amplify-and-forward relaying network. We show that our proposed techniques allow the selection to be adaptive to the residual self-interference (SI) level for each of the available relays in the network. The adaptivity of our selection schemes is manifested through a hybrid system that is based on FD relaying and switching based on the overall channel conditions and the statistics of the residual SI channel for each of the relays. In particular, different proposed techniques are shown to be able to adaptively decide on when and how often the used relays should be switched in the case of overwhelming residual SI. Our results show that allowing such a fusion considerably improves the overall performance of the considered relaying scheme in terms of bit error rate compared with state-of-the-art relay selection schemes.