Optimal Hybrid Full-Duplex/Half-Duplex Scheme for Buffer Aided Relay Systems

TL;DR

This paper introduces an optimal hybrid FD/HD relay scheme that maximizes statistical throughput by adaptively selecting transmission modes, significantly outperforming traditional HD systems.

Contribution

It proposes a novel hybrid FD/HD scheme with optimal mode selection using binary programming and KKT conditions, enhancing relay system performance.

Findings

Achieves up to 95% maximum gain over HD systems.

Provides adaptive mode selection based on channel states.

Formulates the problem as a binary integer programming model.

Abstract

Full-duplex (FD) communication has received great interest in recent years due to the potential of doubling the spectral efficiency. However, how to alleviate the detrimental effects of the residual self-interference (RSI) incurred by the FD mode is still a challenging problem. In this paper, focusing on the statistical throughput maximization, we propose an optimal hybrid FD/half-duplex (HD) scheme for the one-way FD buffer aided relay system. To solve this problem, we divide the system into four different transmission modes and formulate the problem as a binary integer programming problem. By relaxing the binary variables to be continuous ones, we solve the problem using the Karush-Kuhn-Tucker (KKT) optimal conditions. We obtain the selection probability of each mode based on the instantaneous channel outage states. The proposed scheme not only achieves the optimal FD or HD mode selection, but also realizes adaptive source-to-relay or relay-to-destination link selection. Simulation results show that the proposed scheme offers 95% maximum gain over the HD counterparts.