基于混沌加密和Kramers-Kronig接收机的光直接检测系统  

Optical Direct-Detection System Based on Chaotic Encryption and Kramers-Kronig Receiver

作　　者：巩小雪 张天天 张琦涵 张铁凝 郭磊[1] Gong Xiaoxue;Zhang Tiantian;Zhang Qihan;Zhang Tiening;Guo Lei(School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;School of Computer Science and Engineering,Northeastern University,Shenyang 110819,Liaoning,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]东北大学计算机科学与工程学院,辽宁沈阳110819

出　　处：《光学学报》2023年第19期76-84,共9页Acta Optica Sinica

基　　金：国家自然科学基金(62075024,62025105,62071076,62205043,62201105);重庆市自然科学基金(CSTB2022NSCQMSX1334,cstc2021jcyj-msxmX0404);重庆市教委创新研究群体项目(CXQT21019)。

摘　　要：为了实现直接检测(DD)光正交频分复用(OOFDM)系统安全可靠通信,在发送端利用混沌加密技术来提高DDOOFDM系统的安全性,在接收端采用Kramers-Kronig(KK)接收机来解决OFDM信号子载波拍频干扰的问题。利用混沌加密前后的图像像素值分布对系统的安全性进行分析验证。此外,分析了KK接收机的结构和其实现的条件,仿真测试了基于混沌加密和KK接收机的DD-OOFDM系统的误码率性能。Objective Optical orthogonal frequency division multiplexing(OOFDM)technology features the advantages of high spectral efficiency and strong anti-dispersion ability and is of immense interest in optical communication.Additionally,based on the different detection methods at the receiver,optical communication systems are divided into direct detection(DD)and coherent detection systems.Compared with the coherent detection system,DD-OOFDM system has the advantages of low cost,simple structure,and insensitivity to spectral offset and phase noise.Therefore,DD-OOFDM optical communication systems have been widely used.The realization of high-speed information transmission in the DDOOFDM communication systems ensures convenience;nonetheless,information security issues are emerging,such as illegal personnel stealing information through fiber bending and other means;therefore,securing optical communication has become crucial.Compared with traditional encryption methods,chaotic encryption is advantageous because of its hard-topredict nature and limitless chaotic sequence values.Using chaotic mapping sequences to derive keys with no regularity can improve the security of the system.However,in a DD-OOFDM communication system supporting chaotic encryption,since the receiver needs to receive sufficient encrypted information to decrypt it correctly,higher requirements are posed on the system BER.The presence of OOFDM subcarrier beat interference(signal to signal beat interference,SSBI)at the receiver end of the DD-OOFDM system significantly increases the system BER;thus,reducing SSBI becomes the key to improving transmission performance.The traditional method is to insert a protection interval to avoid the overlap of SSBI and OFDM signals,thus eliminating SSBI.However,this decreases the spectrum utilization of the system.The Kramers-Kronig(KK)receiver has the advantages of high spectrum utilization,low hardware complexity,and simple implementation,which can solve the aforementioned problem efficiently.For this reason,the use of a

关 键 词：直接检测 光正交频分复用 子载波拍频干扰 混沌加密 Kramers-Kronig接收机 

分 类 号：TN91[电子电信—通信与信息系统]