基于物理层加密的OFDM可见光通信系统安全传输方案  

Secure transmission scheme of OFDM visible light communication system based on physical layer encryption

作　　者：杨立锐 郭心悦[1] YANG Lirui;GUO Xinyue(Key Laboratory of Optical Technology and Instrument for Medicine,Ministry of Education,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学医用光学技术与仪器教育部重点实验室,上海200093

出　　处：《光通信技术》2023年第1期17-24,共8页Optical Communication Technology

基　　金：国家重点研发计划项目(2018YFB1801503)资助。

摘　　要：针对可见光通信(VLC)链路的数据传输安全性不高的问题。在正交频分复用(OFDM)VLC系统中,提出一种比特级、符号级和相位联合加密的三级物理层加密方案。首先,引入Logistic映射的混沌序列加密方法降低加密数据的相关性,提高加密数据的安全性和系统的传输性能;然后,提出基于S替换表的星座映射,根据不同的S替换表生成对应的星座映射关系,使得原始二进制比特数据和加密后生成的数字调制信号之间始终保持格雷映射的特性,保证格雷增益。仿真结果表明:相比现有的方案,提出的物理层加密方案不仅具有更高的安全性,还降低了OFDM VLC系统发送数据的峰均功率比,缓解了发光二极管(LED)发射端产生的非线性失真,提升了系统的误码率性能。Aiming at the problem of low data transmission security of visible light communication(VLC)link,the data transmission security problem of VLC link is becoming more and more prominent.In orthogonal frequency division multiplexing(OFDM)VLC system,a three-level physical layer encryption scheme with specific level,symbol level and phase joint encryption is proposed.Firstly,the chaotic sequence encryption method of Logistic mapping is introduced to reduce the correlation of encrypted data,improve the security of encrypted data and the transmission performance of the system.Then,the constellation mapping based on S replacement table is proposed,and the corresponding constellation mapping relationship is generated according to different S replacement tables,so that the characteristics of gray mapping are always maintained between the original binary bit data and the digital modulation signal generated after encryption,and the gray gain is guaranteed.The simulation results show that compared with the existing schemes,the proposed physical layer encryption scheme not only has higher security,but also reduces the pek-per-power ratio of the data sent by the OFDM VLC system,alleviates the nonlinear distortion generated by the light-emitting diode(LED)transmitter,and improves the bit error rate performance of the system.

关 键 词：可见光通信 光正交频分复用 物理层安全 比特级加密 星座替换 

分 类 号：TN929.1[电子电信—通信与信息系统]