Link selection based on switching between full‐duplex and half‐duplex modes

Abstract

Multiple‐input multiple‐output systems can achieve a full sum rate (SR) via full duplex (FD). However, its performance is degraded by self‐interference (SI) that occurs between the transmitter and receiver at the same node and thus is constrained by error floors. Conversely, half duplex (HD) can avoid the SI albeit at lower spectral efficiency, and the slope of its error curve is determined by the diversity order. In this study, a link selection scheme based on switching between FD and HD is examined as a simple method to improve the bit error rate (BER) performance of FD systems. In the proposed link selection algorithm, either FD or HD is selected based on the received minimum distance and signal‐to‐interference plus noise ratio. Simulation results indicate that the proposed hybrid FD/HD switching system offers significant BER performance improvement when compared with that of the conventional FD and FD based on only the received minimum distance under the same fixed SR. Under relatively sufficient SI cancellation, it is demonstrated to outperform the HD with a diversity advantage in low and medium signal‐to‐noise ratio region.

Keywords

• full duplex (fd)
• half duplex (hd)
• joint transmit and receive antenna selection
• maximum likelihood (ml) receiver
• x‐duplex (xd)