基于DCT级联ICF算法降低相干光正交频分复用系统峰均抑制比  

Reducing Peak-to-average Power Ratio of Coherent Optical Orthogonal Frequency Division Multiplexing System by DCT Cascading ICF Algorithm

作　　者：张楠[1] 童峥嵘[1] 张卫华[1] 刘叶[1] ZHANG Nan;TONG Zhengrong;ZHANG Weihua;LIU Ye(Engineering Research Center of Optoelectronic Devices and Communication Technology,Ministry of Education,Tianjin Key Laboratory of Film Electronic and Communication Devices,School of Integrated Circuit Science and Engineering,Tianjin University of Technology,Tianjin 300384,China)

机构地区：[1]天津理工大学集成电路科学与工程学院薄膜电子与通信器件重点实验室,教育部光电器件与通信技术工程研究中心,天津300384

出　　处：《光子学报》2022年第9期198-206,共9页Acta Photonica Sinica

基　　金：National Natural Science Foundation of China(No.62003237);Tianjin Enterprise Science and Technology Commissioner Project(No.20YDTPJC01700);Tianjing Municipal Education Commission Scientific Research Project(No.2017ZD15)。

摘　　要：为解决相干光正交频分复用中高峰均抑制比的问题,提出一种离散余弦变换(DCT)和迭代限幅滤波(ICF)级联的新算法。ICF算法是对限幅算法进行改善,添加了迭代过程,可以改善限幅运算对系统误码率的影响。基于DCT算法有较小的误码率和低计算复杂度的特点,所提算法对频域调制信号进行离散余弦变换,以降低高峰值信号的概率,再通过级联ICF算法来实现对峰均抑制比的降低。结果表明,与原始信号相比,当互补累积分布函数为10^(-4)时,所提算法的优化幅度为4.685 dB。在误码率为10^(-3)时,所提算法的光信噪比为20.96 dB,同时能做到长距离传输。除此之外,所提方案的总计算量为19970。仿真数据表明,考虑峰均抑制比、误码率和计算复杂度等综合因素,所提方案性能最优。Optical Orthogonal Frequency Division Multiplexing(OOFDM)technology is a new optical transmission technology.It is the product of the combination of Orthogonal Frequency Division Multiplexing(OFDM)technology and optical fiber communication technology,and has all the advantages of these two technologies.In recent years,OOFDM has become one of the research hotspots in the field of optical communication due to its unique advantages,especially the Coherent Optical Orthogonal Frequency Division Multiplexing(CO-OFDM)system.The CO-OFDM system has the advantages of high spectral efficiency,receiving sensitivity,and robustness,which make it become a research hotspot for realizing high-capacity,high-speed and long-distance optical fiber communication.The CO-OFDM signal is superimposed by modulated subcarrier signals.When the phases of the multiple subcarrier signals are the same,the superimposed signal power can be much greater than the average power,which can result in high Peak-to-average Power Ratio(PAPR).High PAPR not only causes nonlinear distortion when the system passes through optical amplifiers,DAC,ADC and other devices,but also leads to a decrease Bit Error Rate(BER).To solve the PAPR problem of CO-OFDM in OOFDM,the characteristics of related algorithms are studied.The clipping algorithm is the nonlinear processing of the signal,it will cause degradation performance such as high BER,low transmission rate,short transmission distance.An improved ICF algorithm is studied,which can improve the impact of the clipping algorithm on the system BER because of the iterative process.DCT transform is an orthogonal transform,which has a good effect of decorrelation and concentration the energy of the signal.DCT can change the correlation of the input sequence and further reduce the PAPR of the signal.A new structure of the DCT cascade improved clipping algorithm is proposed.From the time domain waveform diagram,the peak value of the original signal is 4.485,and the peak value of the DCT-ICF algorithm is 3.273.Compared with th

关 键 词：正交频分复用 峰均抑制比 误码率 迭代限幅滤波 离散余弦变换 

分 类 号：TN929.1[电子电信—通信与信息系统]