安全增强型相干光正交频分复用/偏移正交幅度调制系统的混沌加密  

Chaotic Encryption Methods for Security-Enhanced Coherent Optical OFDM/OQAM Systems

作　　者：余自芳 方熙 周扬 YU Zifang;FANG Xi;ZHOU Yang(Beijing Electronic Science and Technology Institute,Beijing 100070,P.R.China)

机构地区：[1]北京电子科技学院,北京市100070

出　　处：《北京电子科技学院学报》2021年第3期57-65,共9页Journal of Beijing Electronic Science And Technology Institute

基　　金：国家自然科学基金资助项目(61701008);北京高校“高精尖”学科建设项目(No.20210093Z0401)。

摘　　要：与传统正交频分复用(OFDM)相比,正交频分复用/偏移正交幅度调制(OFDM/OQAM)系统将子栽波的正交条件从复数域变化到实数域,滤波器组的时频聚焦特性可以抑制符号间干扰和栽波间干扰。因此,相干光OFDM/OQAM可以去除插入在连续OFDM块之间的循环前缀,从而提高系统的频谱效率。近些年由于网络的快速发展和广泛应用,网络信息安全面临的干扰、物理基础设施攻击等威胁越来越严重。因此,提高系统安全性、保护传输信息变得尤为重要。由于混沌相关的遍历性、高随机性和对初始值的敏感性等特性,混沌加密具有较高的安全性和较低的实现复杂度。此外,由于OFDM中灵活的数字信号处理机制,混沌加密可以很容易地融入到OFDM和OFDM/OQAM系统中。以相干OFDM/OQAM系统为基础,利用混沌优点,提出了两种加密方法,分别是基于混沌交叉映射的混沌星座置乱方法(CCS)和基于布朗运动的星座置乱加密方法(BCS),对传输中的信息进行加密,从而保护信息,提高系统安全性。Compared with conventional orthogonal frequency division multiplexing(OFDM)systems,orthogonal frequency division multiplexing/offset quadrature amplitude modulation(OFDM/OQAM)systems relax the orthogonal conditions between subcarriers from the complex domain to the real domain,and the inter-symbol interference(ISI)and inter-carrier interference(ICI)could also be suppressed by using the filter banks with high time-frequency localization(TFL)property.Thus,OFDM/OQAM could eliminate the cyclic prefixes(CP)inserted between different OFDM blocks to achieve a higher spectral efficiency.In recent years,with the rapid development and wide application of the network,information security is facing increasingly serious threats such as interference and physical infrastructure attacks,and enhancing system security and protecting information are of great significance.Due to the characteristics of chaos such as ergodicity,high randomness,and sensitivity to initial values,chaotic encryption has high security and low complexity.In addition,chaotic sequences could be easily integrated into OFDM and OFDM/OQAM systems to encrypt information due to the flexible digital signal processing mechanism in OFDM.Based on coherent OFDM/OQAM system,two encryption methods,namely chaotic constellation scrambling(CCS)based on chaotic cross mapping and Brownian-motion constellation scrambling(BCS)based on Brownian movement,are proposed utilizing the advantages of chaos to encrypt the transmission information to enhance the system security.

关 键 词：正交频分复用/偏移正交幅度调制 光通信 安全性增强 混沌加密 

分 类 号：TN918.91[电子电信—通信与信息系统]