Physical Layer Security for Land Mobile Satellite Communication Networks With User Cooperation

In this paper, we investigate the physical layer security of land mobile satellite (LMS) communication networks, where the multiple legitimate users and eavesdroppers are considered in the system. In order to obtain the best system performance, we propose the cooperating scheme for legitimate users to receive the main signal. Besides, we design two representative eavesdropping scenes for the eavesdroppers, namely, Scene I, colluding scene: the eavesdroppers cooperate with each other and wiretap the information of the main channel together, and the Scene II, non-colluding scene which is the best eavesdropping scene, namely, the most harmful eavesdropper will be selected to overhear the information channel. Furthermore, we obtain the closed-form expressions for the non-zero probability of secrecy capacity, the secrecy outage probability (SOP), and average secrecy capacity (ASC) based on the proposed user cooperation scheme in the presence of two eavesdropping scenes. In order to obtain more insights at the high signal-to-noise-ratios, the asymptotic expressions for the SOP and ASC are also derived under two scenes, from which we can derive the effect of different parameters on the system performance conveniently. Finally, some representative Monte Carlo simulation results are provided to verify the correctness of the obtained analytical results.