Physical Layer Security for MIMO Wireless System Using MRC over Rayleigh Fading Channels

Exponentially increasing users are expected to be supported by the fifth-generation (5G) network. 5G technology is designed to meet the growing demands of an increasing number of connected devices and applications by providing higher data rates, lower latency, and better network capacity. However, due to the open nature of wireless communication, information security and privacy have emerged as critical concerns in wireless communication. To address these concerns, 5G networks make use of physical layer security techniques to protect the confidentiality of wireless communication. In this paper, we investigate the secrecy capacity and secrecy outage probability of a multiple input multiple output (MIMO) system in a Rayleigh environment. To enhance the system’s security, we employ a cooperative jammer. We also define the diversity order for the wiretap and main channels and investigate its effects on the secrecy capacity as well as secrecy outage probability. Furthermore, we improve the system’s security using the maximal ratio combining (MRC) scheme, even under low signal-to-noise ratio (SNR). Space-time transition (STT) is used as an antenna selection scheme. Our numerical expressions and simulation results demonstrate that using cooperative jammers and the MRC scheme can enhance the secrecy of the system, even when the main channel experiences low SNR. © 2023, The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd.