Joint relay-pair selection for buffer-aided successive opportunistic relaying

ABSTRACTIn this work, we present a buffer‐aided successive opportunistic relaying scheme that aims at improving the average capacity of the network when inter‐relay interference arises between relays that are selected for simultaneous transmission and reception. We propose a relay selection policy that, by exploiting the benefits of buffering at the relays, decouples the receiving relay at the previous time slot to be the transmitting relay at the next slot. Furthermore, we impose an interference cancellation threshold allowing the relay that is selected for reception to decode and subtract the inter‐relay interference. The proposed relaying scheme selects the relaying pair that maximises the average capacity of the relay network. Its performance is evaluated through simulations and comparisons with other state‐of‐the‐art half‐duplex and full‐duplex relay selection schemes, in terms of outage probability, average capacity and average delay. The results reveal that a trade‐off has to be made between improving the outage at the cost of reduced capacity and increased delay and vice versa. Finally, conclusions are drawn and future directions are discussed, including the need for a hybrid scheme incorporating both half‐duplex and full‐duplex characteristics. Copyright © 2013 John Wiley & Sons, Ltd. Here, a buffer‐aided successive relaying scheme is proposed that aims at improving the average capacity of the network which is degraded by inter‐relay interference. As the relay which receives from the source and the relay which transmits towards the destination are activated simultaneously, opportunistic relay selection is employed to select a relay‐pair that achieves interference cancellation or avoids excessive interference. The results reveal that improved capacity and lower delay come at the cost of increased outage probability.