Energy-efficiency Priority Based Buffer-aided Relay Selection and Power Allocation Strategy in SWIPT Network

In simultaneous wireless information and power transfer (SWIPT) network, a pair of half-duplex buffer-aided relay can simultaneously transmit and receive information within one time slot, which implements virtual full-duplex communication. Aiming at the resource allocation problem in virtual full-duplex SWIPT network, optimal buffer-aided relay selection and subcarrier power allocation strategy in SWIPT network is investigated. Firstly, mathematical model is constructed with the reference of water-filling factor aided search algorithm. With the target of energy-efficiency maximization, the proposed scheme solves optimal problem to choose the best SWIPT forward relay with the consideration of multiple constraint conditions such as power, information transmit rate, as well as the interference of the chosen optimal receive relay. The optimal solution of subcarrier power allocation for the best SWIPT forward relay is obtained. Simulation results show that, compared with the joint resource allocation algorithm that aims to maximize end-to-end achievable rate, the proposed strategy takes SWIPT inter-relay interference into account. Moreover, the proposed strategy obtains higher energy efficiency with larger transmit power at the source.