Secure and Energy Efficient Transmission for IRS-Assisted Cognitive Radio Networks
Secure and Energy Efficient Transmission for IRS-Assisted Cognitive Radio Networks
复制标题
IRS 辅助认知无线电网络的安全且节能的传输
DOI：
10.1109/tccn.2021.3114176
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发表时间：
2022-03-01
影响因子：
8.6
通讯作者：
Zeng, Xin
中科院分区：
文献类型：
--
作者：
Wu, Xuewen;Ma, Jingxiao;Zeng, Xin
认知无线电网络（CRN）中，由于对主用户（PU）的干扰限制以及与PU共享频谱，频谱效率（SE）和次用户（SU）的安全性成为两个主要问题。智能反射面（IRS）是近年来提出的一种革命性技术，它可以帮助增强无线通信的SE和物理层安全性。本文研究了IRS在多天线认知基站中的应用，其中多天线认知基站（CBS）利用分配给PU的频谱，在存在多个协作窃听者（Eves）的情况下，通过IRS与SU进行通信。为了实现保密率（SR）和能量消耗之间的权衡，我们调查的保密能量效率（SEE）最大化问题，通过联合设计的CBS和IRS的反射波束形成的发射波束形成。针对耦合变量非凸优化问题，提出了一种迭代交替优化算法，对子问题1采用基于迭代罚函数的算法，对子问题2采用两凸函数差分法。此外，我们提供了一个二阶锥规划（SOCP）的近似方法，以减少计算复杂度。最后，仿真结果表明，IRS可以显着提高SE和增强CRN的物理层安全性。此外，我们提出的算法在实现SR和能量消耗之间的权衡的有效性和优越性进行了验证。
The spectrum efficiency (SE) and security of the secondary users (SUs) in the cognitive radio networks (CRNs) have become two main issues due to the limitation interference to the primary users (PUs) and the shared spectrum with the PUs. Intelligent reflecting surface (IRS) has been recently proposed as a revolutionary technique which can help to enhance the SE and physical layer security of wireless communications. This paper investigates the application of IRS in an underlay CRN, where a multi-antenna cognitive base station (CBS) utilizes spectrum assigned to the PU to communicate with a SU via IRS in the presence of multiple coordinated eavesdroppers (Eves). To achieve the trade-off between the secrecy rate (SR) and energy consumption, we investigate the secrecy energy efficiency (SEE) maximization problem by jointly designing the transmit beamforming at the CBS and the reflect beamforming at the IRS. To solve the non-convex problem with coupled variables, we propose an iterative alternating optimization algorithm to solve the sub-problems alternately, by utilizing an iterative penalty function based algorithm for sub-problem 1 and the difference of two-convex functions method for sub-problem 2. Furthermore, we provide a second-order-cone-programming (SOCP) approximation approach to reduce the computational complexity. Finally, the simulation results demonstrate that IRS can help significantly improve the SE and enhance the physical layer security in the CRNs. Moreover, the effectiveness and superiority of our proposed algorithm in achieving the trade-off between the SR and energy consumption are verified.