时间反转OFDM系统中增强安全性能的功率分配与人工噪声设计  

Power Allocation and Artificial Noise Design of Time-Reversal OFDM System to Enhance Security Performance

作　　者：雷维嘉[1,2] 毕文佳 雷宏江[1,2] 唐宏[1,2] LEI Wei-jia;BI Wen-jia;LEI Hong-jiang;TANG Hong(School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;Chongqing Key Laboratory of Mobile Communications Technology,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)

机构地区：[1]重庆邮电大学通信与信息工程学院,重庆400065 [2]重庆邮电大学移动通信技术重庆市重点实验室,重庆400065

出　　处：《电子学报》2024年第5期1570-1581,共12页Acta Electronica Sinica

基　　金：国家自然科学基金(No.61971080)。

摘　　要：时间反转技术特有的时空聚焦特性使其具有抗窃听能力.本文对提高时间反转正交频分复用系统安全性能的优化方案进行研究.首先,通过应用时间反转预滤波的时空聚焦特性来提高合法接收端相对于窃听端的信号强度;然后,以最大化保密速率为目标对子载波的功率分配进行优化.为进一步提升系统保密传输能力,利用循环前缀提供的自由度实现零空间人工噪声,在对窃听端形成有效干扰的同时,不对合法接收端造成影响.通过对子载波功率分配和人工噪声协方差阵进行联合优化,最大化系统的保密传输速率.仿真结果表明,所提优化方案能显著提高系统的保密速率.Time reversal technology has natural anti-eavesdropping capability due to its unique spatial and temporal focusing capability.In this paper,an optimization scheme to improve the security performance of time reversal OFDM system is studied.Firstly,the temporal and spatial focusing characteristics of time reversal pre-filtering are applied to improve the signal strength of the legitimate receiver relative to the eavesdropper,and then the power of the subcarriers is optimized to maximize the security rate.In order to further improve the secure capability of the system,the zero-space artificial noise is realized by employing the degree of freedom provided by the circular prefix,which can effectively interfere with the eavesdropper,while does not interfere with the legitimate receiver.Then,the subcarrier power and the covariance matrix of the artificial noise are optimized to maximize the security transmission rate.Simulation results show that the proposed scheme can significantly promote the security rate of the system.

关 键 词：物理层安全 正交频分复用 时间反转 功率分配 人工噪声 

分 类 号：TN918[电子电信—通信与信息系统]