Cooperative buffer-aided relaying using full-duplex relays with flow control

In this paper, we investigate buffer-aided cooperative relaying schemes using full-duplex (FD) relay nodes with flow control. We show that incorporating various transmission options combined with proper successive interference cancellation can better exploit the opportunism of fading channels, leading to improved achievable rates. We analytically derive the optimal policy for node selection and link scheduling. To deal with the delay incurred at relay nodes, we propose flow control using a threshold-based policy on relays' queues. For performance analysis, we develop a novel technique to derive a delay estimate of the controlled queues with general arrival and service statistics. Numerical results show that the proposed scheme achieves higher throughputs than conventional relaying schemes without FD relaying, and that the proposed estimate closely approximates the actual delay. For the delay-constrained case, our scheme is shown to achieve an improved tradeoff between throughput and delay.