Secrecy Throughput Optimization in the Buffer-aided MIMO Full-Duplex Relaying System

Abstract

In this paper, the physical layer security is studied in a buffer-aided MIMO relaying system, which consists of a source, a destination, a multi-antenna relay and multiple eavesdroppers. The relay operates in either half-duplex mode or full-duplex mode, based on the channel state information (CSI) of legitimate links. The exact closed-form expressions for the secrecy throughput and the outage probability of the buffer-aided MIMO relaying system are derived. In this work, the transmission rates can be adjusted at the source and relay instead of the predetermined transmission rates in the existing work. The optimal transmission rates are obtained to maximize the average secrecy throughput under the intended secrecy outage probability constraint, where only statistical CSI is needed when the optimization problem is solved. Numerical results show that analytical results of the secrecy outage probability agree with simulation results well. Compared with the conventional bufferless relaying schemes, the proposed buffer-aided relaying scheme achieves a higher throughput, as well as preserving the secrecy performance.