Optimal Link Selection in Multi-Source and Multi-Destination Buffer-Aided Relay Networks

This paper studies the link selection protocol for the relay network consisting of N pairs of sources and destinations, and one half-duplex decode-and-forwarding (DF) relay equipped with data buffers. An optimal link selection scheme is proposed to maximize the average throughput of the relay network. Using the Karush-Kuhn-Tucker (KKT) conditions, the decision function for the optimal link selection is also obtained for Rayleigh fading channels. Simulation are given to verify the proposed scheme. The results show that the proposed scheme achieves not only significantly higher data rate than the classic max-min scheme without data buffers at the relay, but also the existing buffer-aided link selection schemes such as the max-max scheme. This making the proposed scheme attractive in practice.