物理学报Issue(14)：1-7,7.DOI:10.7498/aps.64.144203
基于数字相干叠加的相干光正交频分复用系统中光纤非线性容忍性研究∗
Fib er nonlinearity tolerance research of coherent optical orthogonal frequency division multiplexed system based on digital coherent sup erp osition
摘要
Abstract
Fiber nonlinearity of optical orthogonal frequency division multiplexed (OFDM) system restricts the capacity im-provement of optical fiber transmission. In this paper, we propose a novel digital coherent superposition (DCS) scheme to improve the tolerance to fiber nonlinearity in a coherent optical orthogonal frequency division multiplexed system. In simulation, 71.53 Gbit/s orthogonal frequency division multiplexed signal per channel with Hermitian symmetry is trans-mitted over 400 km standard single mode fiber in a wave division multiplexed-polarization-division multiplexed-coherent optical orthogonal frequency division multiplexed system with five channels. The 4-quadrature amplitude modulation is used for symbol mapping. For the receiver, after the conventional OFDM signal processing, we conduct DCS for OFDM subcarrier pairs, which requires only conjugation and summation in the x, y polarization direction, respectively. Firstly, the channel spacing is 25 GHz, the maximum signal-to-noise ratio improvement is 9.05 dB or 6.02 dB with or without symmetric dispersion compensation compared with a conventional orthogonal frequency division multiplexed system. The optimum launch power is increased by 2 dB. Secondly, the channel spacing is changed to 50 GHz to investigate the nonlinearity tolerance at different channel spacings in the wave division multiplexed system, the maximum signal-to-noise ratio improvement is 8.75 dB or 4.9 dB with or without symmetric dispersion compensation, respectively. Theoretical and simulation analysis show that the proposed method in this paper can effectively mitigate the first-order nonlinear distortions and hence improve the tolerance of coherent optical orthogonal frequency division multiplexed system with different channel spacings to fiber nonlinear effects.关键词
光纤通信/光正交频分复用/数字相干叠加/光纤非线性Key words
optical communication/optical orthogonal frequency division multiplexed/digital coherent superposition/fiber nonlinearity引用本文复制引用
陈雪梅,张静,易兴文,曾登科,杨合明,邱昆..基于数字相干叠加的相干光正交频分复用系统中光纤非线性容忍性研究∗[J].物理学报,2015,(14):1-7,7.基金项目
国家高技术研究发展计划(批准号:2013AA01340,2012AA011302,2012AA011304)、国家自然科学基金(批准号:61405024,61107060,61405024)和中央高校基本科研业务费专项资金(批准号：ZYGX2014J004)资助的课题.@@@@* Project supported by the National High Technology Research and Development Program of China (Grant Nos.2013AA01340,2012AA011302,2012AA011304), the National Natural Science Foundation of China (Grant Nos.61405024,61107060,61405024), and the Fundamental Research Funds for the Central Universities of Ministry of Education of China (Grant No. ZYGX2014J004) （批准号:2013AA01340,2012AA011302,2012AA011304）
