LAUSR

In this paper, we investigate the security and reliability trade-off (SRT) for a wireless sensor network (WSN) which consists of one cluster head (CH), multiple users, and one eavesdropper (E), where the eavesdropper attempts to tap the confidential transmission between multiple users and CH. We first present two multiuser scheduling schemes, namely the selection combining (SC) scheme and the switch-and-examine combining with post-selection (SECps) scheme to enhance physical-layer security (PLS) of the WSN system. For comparison purposes, the round-robin scheduling (RRS) scheme is also considered as a baseline. Then, we analyze the SRT of the RRS, SECps, and SC schemes by deriving their closed-form outage and intercept probability expressions under the joint impact of hardware impairment (HI) and co-channel interference (CCI). And, secrecy diversity analysis of the three schemes is also carried out. Numerical results show that the SC and SECps scheme outperform the RRS scheme in terms of the SRT performance, where the SC scheme can achieve the best SRT performance at the cost of an increased channel estimation complexity. Moreover, a trade-off between the security and reliability can be achieved for each of the RRS, SECps, and SC schemes by adjusting the overall data rate and signal-to-noise ratio (SNR).