Secrecy Throughput in Full-Duplex Multiuser MIMO Short-Packet Communications

In this letter, we consider the physical-layer security (PLS) in full-duplex (FD) multiuser multiple-input-multiple-output (MIMO) short-packet communications, where a base station (BS) transmits precoded signals for secure downlink multicast while receiving signals from uplink users. To quantify the PLS performance in the worst-case scenario, we consider the possible maximum wiretapping capability of a multi-antenna eavesdropper. Taking into account the self-interference (SI) in FD mode and the co-channel interference (CCI) from uplink to downlink, we analyst the secrecy throughput in finite blocklength regime and obtain its analytic expression, which perfectly matches asymptotic and simulation results in various scenarios. Moreover, the investigations on secrecy throughput substantiate that the FD multiuser MIMO systems outperform their half-duplex counterparts given the SI being sufficiently suppressed and the CCI being well managed.