零填充双模光正交频分复用索引调制的三级分步检测算法  

Three-Stage Stepwise Detection Algorithm for Zero-Padded Dual-Mode Optical OFDM Index Modulation

作　　者：王惠琴[1] 周伟煜 唐崎涵 王真 吴鹏飞[2] 彭清斌[1] 张悦 Wang Huiqin;Zhou Weiyu;Tang Qihan;Wang Zhen;Wu Pengfei;Peng Qingbin;Zhang yue(School of Computer and Communication,Lanzhou University of Technology,Lanzhou 730050,Gansu,China;School of Automation and Information Engineering,Xi’an University of Technology,Xi’an 710048,Shaanxi,China)

机构地区：[1]兰州理工大学计算机与通信学院,甘肃兰州730050 [2]西安理工大学自动化与信息工程学院,陕西西安710048

出　　处：《光学学报》2024年第11期13-22,共10页Acta Optica Sinica

基　　金：国家自然科学基金(62261033,61861026,62265010);甘肃省重点研发计划(22YF7GA056)。

摘　　要：传统光正交频分复用索引调制(OOFDM-IM)有效改善了系统的误码性能,但大量静默子载波的存在造成了频谱资源的浪费,因此提出一种零填充双模光正交频分复用索引调制(ZDM-OOFDM-IM)系统。首先,ZDM-OOFDM-IM系统通过在激活子载波上加载两种不同模式的星座符号并保留静默子载波,而额外增加模式顺序索引,可获得更快的传输速率。其次,依据系统中的信号特征,将贪婪算法、对数似然检测算法和改进型K均值聚类算法(KMC++)相结合,提出一种基于KMC++的三级分步检测算法。实验结果表明,在误码率为3.8×10^(-3)的情况下,ZDM-OOFDM-IM系统在室内实现了3 m的传输。同时,相较于最大似然检测算法,所提检测算法有效降低了检测复杂度,而且获得了更优的误码性能。Objective Optical orthogonal frequency division multiplexing index modulation(OOFDM-IM)is a novel multicarrier technique that achieves higher transmission rates by additionally adding mode order indexing via loading two different modes of constellation symbols on the active subcarriers and retaining the silent subcarriers.At the same time,the presence of silent subcarriers improves the bit error rate(BER)performance of the system.However,the presence of silent subcarriers also brings a waste of spectrum resources.Therefore,in this paper,a zero-padded dual-mode optical orthogonal frequency division multiplexing index modulation(ZDM-OOFDM-IM)is proposed to improve the transmission rate.Meanwhile,in order to solve the problem of excessive system detection complexity,a three-level stepwise detection algorithm based on K-mean clustering algorithm(KMC++)is proposed by combining the greedy(GD)algorithm,loglikelihood ratio(LLR)algorithm,and KMC++algorithm.Methods In the ZDM-OOFDM-IM system,the active subcarrier was selected by the subcarrier index,and the constellation symbols of two different modes were mapped by the symbol information.Then,the modulation symbols were loaded on the active subcarriers according to the order index to complete signal modulation.After orthogonal frequency division multiplexing(OFDM)data block merging,inverse fast Fourier transform,non-zero clipping,and other processing,the light source sent it out.The optical signal transmitted through the atmospheric turbulence channel was received by the detector and could be restored to the original signal after processing by fast Fourier transform,subcarrier recovery,and maximum likelihood(ML)detection.According to the subcarrier index,constellation pattern order,and different characteristics of constellation symbols in the ZDM-OOFDM-IM system,GD,LLR,and KMC++algorithms were used to detect the proposed detection algorithm,so as to reduce the complexity of the receiver signal detection.Finally,the feasibility of the system and the proposed algorithm were

关 键 词：光通信 索引调制 分步检测 K均值聚类 实验验证 

分 类 号：TN929.12[电子电信—通信与信息系统]