基于人工噪声频谱覆盖的OFDM系统物理层加密算法

发布时间：2018-06-08 14:35

本文选题：物理层安全 + 人工噪声　；参考：《西北大学》2017年硕士论文

【摘要】：随着无线通信技术朝着宽带化、融合化、智能化和泛在化的方向不断发展,无线通信系统受到的安全威胁也越来越严重,传统的链路层加密算法遇到严重挑战,人们开始关注物理层加密算法。但是,现有的物理层加密算法都是基于物理层的基带符号运算来完成,没有考虑射频域的频谱泄露带来的安全问题,存在严重的安全隐患。本文针对这一安全隐患,在分析OFDM信号频谱特点的基础上,提出了一种基于频谱分析的攻击方法,并给出两个成功攻击的案例;在此基础上,以抑制载波泄露为出发点,设计了一种基于人工噪声频谱覆盖的物理层加密算法。算法通过将密钥控制产生的具有特殊频谱的人工噪声信号在时间域与原始OFDM信号相叠加,实现两种信号在频率域的频谱相互重叠,相互干扰和相互保护作用。理论分析和仿真实验结果表明,算法可以有效破坏原系统子载波之间的正交性,可以覆盖和干扰原系统的频谱,在保证密钥安全的同时,可以达到抑制信息载波泄露的目的;算法实现简单,安全性高,对原系统带宽、峰均比及误码率等正常性能影响小。
[Abstract]:With the development of wireless communication technology towards broadband, fusion, intelligence and ubiquity, the security threats to wireless communication systems are becoming more and more serious, and the traditional link-layer encryption algorithms face serious challenges. People began to pay attention to the physical layer encryption algorithm. However, the existing physical layer encryption algorithms are based on the physical layer of baseband symbol operation to complete, did not consider the RF domain spectrum leakage caused by the security problems, there are serious security risks. In this paper, based on the analysis of OFDM signal spectrum characteristics, a spectrum analysis based attack method is proposed, and two successful attack cases are given, based on which, the carrier leakage suppression is the starting point. A physical layer encryption algorithm based on artificial noise spectrum coverage is designed. By superposing the artificial noise signal with special spectrum produced by key control in time domain with the original OFDM signal, the spectrum of the two signals in frequency domain overlaps, interferes and protects each other. The theoretical analysis and simulation results show that the algorithm can effectively destroy the orthogonality between the subcarriers of the original system, cover and interfere with the spectrum of the original system, ensure the security of the key, and achieve the purpose of suppressing the information carrier leakage. The algorithm has the advantages of simple implementation, high security and little influence on the normal performance of the original system such as bandwidth, peak-to-average ratio and bit error rate.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.53

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