面向非可信中继系统的无线携能安全通信OA

Addressing the communication security problem in cooperative transmission systems with energy-constrained untrusted relays,this paper proposes a jamming-assisted secure simultaneous wireless information and power transfer(SWIPT)scheme.Considering that the eavesdropping behavior of untrusted relays depends on their current energy storage,the system aims to regulate wireless energy harvesting to intervene in relay operating states,thereby reducing the eavesdropping probability from a long-term communication perspective.With the objective of maximizing the long-term average secrecy capacity,a joint optimization problem of adaptive relay selection and power allocation is formulated.Leveraging Lyapunov optimization theory,the long-term average optimization problem is transformed into a series of discrete-time mixed-integer fractional programming(MIFP)problems.For the resulting MIFP problem,a relay selection strategy that maximizes average secrecy capacity is proposed,and an epigraph reformulation-assisted successive convex approximation power allocation algorithm is designed to obtain the KKT solution for joint power allocation.Simulation results demonstrate that compared with existing best energy and maximum link relay selection strategies,the proposed relay selection strategy significantly enhances the system average secrecy capacity.Furthermore,unlike conventional untrusted relay cooperative transmission systems,in the considered scenario,system security improves with an increasing number of relays under low signal-to-noise ratio conditions.