OFDM系统中基于三维星座旋转的物理层安全加密算法  

A Novel Physical Layer Encryption Algorithm Based on Three Dimensional Constellation Rotation in OFDM System

作　　者：李小倩 李为[1] 雷菁[1] 程龙旺[1] 

机构地区：[1]国防科学技术大学电子科学与工程学院,湖南长沙410073

出　　处：《电子学报》2017年第12期2873-2880,共8页Acta Electronica Sinica

基　　金：国家自然科学基金(No.61502518;No.61372098)

摘　　要：传统无线通信的安全主要依赖于上层加密机制,无法保护物理层调制方式和调制信息的安全.本文针对正交频分复用(OFDM,Orthogonal Frequency Division Multiplexing)系统提出了一种物理层加密调制算法.该算法首先利用相位随机化的信号进行信道探测并提取出等效信道相位信息,然后对三维星座进行物理层调制加密,最后接收端进行解密解调.该方案充分利用了无线信道相位响应的随机性、互易性和位置敏感性,并将该特性用于增强物理层信号的安全性.理论分析和计算机仿真结果表明该算法具有较强的安全性,且相对于传统的QPSK(Quadrature Phase Shift Keying)调制,该算法的误码率性能提升约2.5dB.本文关注于物理层安全,旨在物理信号层提供新的安全保障,在未来5G通信和军事安全通信中有较广泛的应用前景.The security of traditional wireless communication is mainly dependent on the upper layer encryption mechanism,which cannot protect the physical layer modulation mode and the modulation information security. This paper proposes a physical layer encryption modulation method for the orthogonal frequency division multiplexing（ OFDM） system.In this method, the phase random signal is used to detect and extract the equivalent channel phase information, then the 3D（ Three-Dimensional） constellation is modulated in the physical layer,followed by the receiver＇s decryption and demodulation.The scheme makes full use of the wireless channel phase response of randomness, reciprocity and location sensibility,and this characteristic is used to enhance the safety of physical layer signal. Theoretical analysis and computer simulation results show that the algorithm is secure, and compared with the traditional QPSK（ Quadrature Phase Shift Keying） modulation,the BER（ Bit Error Rate） of the proposed algorithm improves about 2. 5 dB. This paper focuses on the physical layer security,which aims at providing a new security for the physical signal layer, and has a wide application prospect in the future 5G communications and military security communications.

关 键 词：三维映射 星座旋转 OFDM 信道探测 密钥提取 物理层安全 

分 类 号：TN911[电子电信—通信与信息系统]