基于自适应ICA的PDM-CO-OFDM系统信道均衡算法

基于独立成分分析法(ICA)能够实现偏振复用相干光正交频分复用(PDM-CO-OFDM)系统的盲信道均衡，与基于导频的信道均衡方法相比，能极大提高系统的频谱利用率。然而这种固定步长的ICA 算法对每个子载波采用迭代算法来计算信道频率响应分离矩阵, 需要经过几十次迭代才能收敛。为有效降低该算法的计算复杂度，提出一种基于自适应步长ICA 的盲信道均衡算法，采用自适应分离步长提高迭代算法的收敛速度。基于100 Gb/s 16进制正交振幅调制(16-QAM)PDM-CO-OFDM 系统，仿真实验表明该自适应算法的系统误码率性能优于固定步长ICA算法的结果，且收敛速度提高5倍以上，能够用于未来高速PDM-CO-OFDM 系统接收端进行高效信道均衡。

Abstract

Compared with the conventional training symbols-based channel equalization method, the blind channel equalization method based on the independent component analysis (ICA) improves considerably the spectral efficiency of the polarization-division-multiplexing coherent-optical orthogonal-frequency-division-multiplexing (PDM- CO- OFDM) systems. However, the blind channel estimation requires the computations of the channel frequency response on subcarrier basis and needs dozens of iterations to converge. To reduce its computational complexity, on the basis of the channel equalization using ICA, a blind channel equalization method is proposed. It is performed by using ICA with adaptive variable step, and the separation step method enhances the convergence rate of the iterative algorithm greatly. For 100 Gb/s PDM-CO-OFDM with 16 quadrature amplitude modulation (16 QAM), it is proved by the simulation results that its convergence rate improves more than five times, compared with the channel equation method by using ICA with fixed iterative step. This method can be used to realize high efficiency channel equalization in the future high speed PDM-CO-OFDM system receivers.

参考文献

[1] W Shieh, I B Djirdjevic. OFDM for Optical Comunications[M]. New York: Academic, 2010.

[2] J Armstrong. OFDM for optical communications[J]. J Lightwave Technol, 2009, 27(3): 189–204.

[3] Q Yang, Y Tang, Y Ma, et al.. Experimental demonstration and numerical simulation of 107-Gb/s high spectral efficiency coherent optical-OFDM[J]. J Lightwave Technol, 2009, 27(3): 168-176.

[4] W Shieh. OFDM for flexible high-speed optical network[J]. J Lightwave Technol, 2011, 29(10): 1560-1577.

[5] S L Jansen, I Morita, H Tanaka. 10×121.0-Gb/s PDM-OFDM transmission with 2-b/s/Hz spectral efficiency over 1000 km of SSMF [C]. OFC/NFOEC, 2008: 100-103.

[6] 邸雪静, 童程, 张霞, 等. 高速相干光通信系统中的自适应步长恒模算法[J]. 光学学报, 2012, 32(10): 1006004.

Di Xuejing, Tong Cheng, Zhang Xia, et al.. Adaptive step- size constant- modulus algorithm for high- speed optical coherent communication system[J]. Acta Optica Sinica, 2012, 32(10): 1006004.

[7] 童峥嵘, 刘颖慧, 曹晔. 100 Gb/s 高速PDM-CO-OFDM 系统峰值平均功率比抑制性能研究[J]. 光学学报, 2015, 32(1): 0106002.

Tong Zhengrong, Liu Yinghui, Cao Ye. Research on peak-to-average power ratio reduction performance for 100 Gb/s high-speed PDM-CO-OFDM systems[J]. Acta Optica Sinica, 2015, 32(1): 0106002.

[8] 郝耀鸿, 王荣, 李玉权, 等. 相干光正交频分复用系统偏振效应研究[J]. 光学学报, 2013, 33(7): 0706021.

Hao Yaohong, Wang Rong, Li Yuquan, et al.. Investigation of polarization effect in coherent optical orthogonal frequency division multiplexing system[J]. Acta Optica Sinica, 2013, 33(7): 0706021.

[9] Xuejun Liu, Yaojun Qiao, Yuefeng Ji. Electronic compensator for 100 Gb/s PDM-CO-OFDM long-haul transmission systems[J]. Chin Opt Lett, 2011, 9(3): 030602.

[10] 陈颖. 偏振复用相干光OFDM 系统信道估计技术的研究和仿真[D]. 北京: 北京邮电大学, 2011.

Chen Ying. Channel Estimation Technology in PDM-CO-OFDM System[D]. Beijing: Beijing University of Posts and Telecommunications, 2011.

[11] 赵晶. 高速相干光通信中偏振复用(PDM)的仿真与实现[D]. 北京: 北京交通大学, 2013.

Zhao Jing. Simulation and Realization in Polarization Division Multiplexing (PDM) of High-Speed Coherent Optical Communication [D]. Beijing: Beijing Jiaotong University, 2013.

[12] X Yi, W Shieh, Y Tang. Phase estimation for coherent optical OFDM[J]. IEEE Photon Technol Lett, 2007, 19(12): 919-921.

[13] Z Yu, X Yi, Q Yang, et al.. Polarization demultiplexing in stokes space for coherent optical PDM-OFDM[J]. Opt Express, 2013, 21(3): 3885-3890.

[14] 高丽娜, 刘剑飞, 曾祥烨, 等. 一种光正交频分复用系统的联合相位均衡方法[J]. 光学学报, 2012, 32(1): 0106004.

Gao Lina, Liu Jianfei, Zeng Xiangye, et al.. Joint phase equalization in optical orthogonal frequency division multiplexing system[J]. Acta Optica Sinica, 2012, 32(1): 0106004.

[15] 王凌子, 唐先锋, 张晓光, 等. PDM-CO-OFDM 系统中基于判决引导与判决反馈的盲相位估计算法[J]. 中国激光, 2014, 41(3): 0305001.

Wang Lingzi, Tang Xianfeng, Zhang Xiaoguang, et al.. Blind phase estimation algorithms based on decision-directed and decision feedback in PDM-CO-OFDM system[J]. Chinese J Lasers, 2014, 41(3): 0305001.

[16] Xi Fang, Chuanchuan Yang, Fan Zhang. Time domain maximum likelihood channel estimation for PDM CO- OFDM systems[J]. IEEE Photon Technol Lett, 2013, 25(6): 805-807.

[17] A Nafta, P Johannisson, M Shtaif. Blind equalization in optical communications using independent component analysis[J]. J Lightwave Technol, 2013, 31(12): 2043-2049.

[18] X Xie, F Yaman, X Zhou, et al.. Polarization demultiplexing by independent component analysis[J]. IEEE Photon Technol Lett, 2010, 22(11): 805-807.

[19] X Li, Wende Zhong, Arokiaswami Alphones, et al.. Channel equalization in optical OFDM systems using independent component analysis[J]. J Lightwave Technol, 2014, 32(18): 3206-3214.

[20] X Li, Wende Zhong, Arokiaswami Alphones, et al.. Channel equalization using independent component analysis in PDM- COOFDM[J]. IEEE Photon Technol Lett, 2014, 26(5): 497-500.

[21] T Adali, Hualiang, Li M Novey, et al.. Complex ICA using nonliner function[J]. IEEE Trans Signal Process, 2008, 56(9): 4536-4544.

[22] 刘俊良, 于凤芹, 基于分离度变步长的自然梯度算法的语音分离[J]. 计算机工程与应用, 2013, 49(21): 216-219.

Liu Junliang, Yu Fengqin. Speech separation based on variable step size natural gradient algorithm depending on separation degree [J]. Computer Engineering and Applications, 2013, 49(21): 216-219.

[23] Lianxi Yuan, Wenwu Wang, Johathon A Chambers. Variable step-size sign natural gradient algorithm for sequential blind source separation[J]. IEEE Signal Process Lett, 2005, 12(8): 589-592.

[24] Hongliang Ren, Jiaxing Cai, Jin Lu, et al.. Novel iteration-free blind phase noise estimation for coherent optical OFDM[J]. Chin Opt Lett, 2014, 12(12): 120603.

[25] Chao Li, Ming Luo, Xiao Xiao, et al.. 63-Tb/s (368×183.3-Gb/s) C-and L-band all-Raman transmission over 160-km SSMF using PDM-OFDM-16QAM modulation[J]. Chin Opt Lett, 2014, 12(4): 040601.

[26] Huang Z, Zhang F, Chen Z. Joint nonlinear electrical equalization in coherent optical PDM DFT-spread-OFDM systems[J]. Chin Opt Lett, 2013, 11(6): 060601.

[27] Rui Ding, Tingting Zhang, Fan Zhang. Experimental demonstration of multigranularity switching between optical DFT- spread-OFDM and Nyquist superchannel[J]. Chin Opt Lett, 2014, 12(11):110604.

[28] Seb J Savory. Digital filters for coherent optical receivers[J]. Opt Express, 2008, 16(12): 804-817.

顾欣, 卢瑾, 任宏亮, 薛林林, 郭淑琴, 覃亚丽, 胡卫生. 基于自适应ICA的PDM-CO-OFDM系统信道均衡算法[J]. 光学学报, 2015, 35(10): 1006003. Gu Xin, Lu Jin, Ren Hongliang, Xue Linlin, Guo Shuqin, Qin Yali, Hu Weisheng. Channel Equalization Using Independent Component Analysis with Adaptive Variable Step in PDM-CO-OFDM[J]. Acta Optica Sinica, 2015, 35(10): 1006003.

基于自适应ICA的PDM-CO-OFDM系统信道均衡算法

关于本站 Cookie 的使用提示

全站搜索

基于自适应ICA的PDM-CO-OFDM系统信道均衡算法

相关论文

相关资讯

关于本站 Cookie 的使用提示

全站搜索