Secure Short-Packet Transmission in Uplink Massive MU-MIMO IoT Networks

In this paper, we investigate a massive multiuser multiple-input-multiple-output (MU-MIMO) system consisting of one base station (BS) equipped with multiple-antenna, one eavesdropping (Eve) node equipped with multiple-antenna and multiple single-antenna user devices (UDs) under short-packet communication scenarios. We use the system average secrecy throughput (AST) as an analysis metric, and derive a theoretically expression of the system AST. For the case where the number of UDs is the same as the number of BS antennas, the approximate closed-form expressions of the system AST are given. The simulation and numerical results validate our theoretical analysis. The system AST can be effectively improved by appropriately increasing the number of antennas at the BS and the transmission signal-to-noise ratio (SNR). Choosing the appropriate transmission blocklength and the number of bits transmitted per block can obtain optimal system security performance.