一种可重构智能表面辅助安全通信保密性能优化方案

A Reconfigurable Intelligent Surface Assisted Secure Communication Secrecy Performance Optimization Scheme

在可重构智能表面辅助的安全通信系统中,为了提高系统的保密性能,同时克服系统收发器带来的硬件损伤,提出了一种基于硬件损伤的可重构智能表面辅助安全通信保密性能优化方案。考虑多窃听者的多输入单输出场景,在基站最大发射功率和可重构智能表面相移单位模的约束下,通过联合优化基站发射波束成形和可重构智能表面相移波束成形,提出了安全通信保密速率最大化问题。针对该优化问题的非凸性和耦合性,提出了一种基于交替优化和半定松弛的有效算法,将原非凸优化问题转化为2个凸优化子问题,并交替迭代优化解,以获得该优化问题的次优解。仿真实验结果表明,所提方案与传统安全通信波束成形方案相比可以获得更高的保密速率。

To improve the secrecy performance of a reconfigurable intelligent surface(RIS)-assisted secure communication system and overcome hardware impairments caused by the system transceiver,an optimization scheme based on hardware impairments for RIS-assisted secure communication is suggested.A multiple-input single-output scenario with multiple eavesdroppershas been considered.Consequently,by jointly optimizing the base station transmit beamforming and RIS phase shift beamforming under the maximum transmit power of the base station with RIS phase shift unit-mode constraints,the secure communication secrecy rate maximization schema is proposed.For the non-convexity and coupling of this optimization problem,an efficient algorithm based on alternating optimization and semidefinite relaxation to transform the original nonconvex optimization problem into two convex optimization sub-problemsis developed.and.Simulation results demonstrate that the proposed scheme can obtain higher secrecy rate in comparison with conventional secure communication beamforming scheme.