基于新型波长标记率调制的无源光网络平滑升级  

Smooth Upgrade of Passive Optical Networks Based on Novel Wavelength Mark Ratio Modulation

作　　者：陈泳键 卢旸[1] 成亮[2] 姚陈 吕韵欣 翟彦蓉 毕美华[1] Chen Yongjian;Lu Yang;Cheng Liang;Yao Chen;LüYunxin;Zhai Yanrong;Bi Meihua(School of Communication Engineering,Hangzhou Dianzi University,Hangzhou 310018,Zhejiang,China;China Information Technology Designing and Consulting Institute Co.,Ltd.,Shanghai 200040,China)

机构地区：[1]杭州电子科技大学通信工程学院,浙江杭州310018 [2]中讯邮电咨询设计院有限公司,上海200040

出　　处：《光学学报》2025年第2期136-144,共9页Acta Optica Sinica

基　　金：浙江省自然科学基金(LY23F050011);浙江省教育厅科研项目(Y202351769,Y202455337)。

摘　　要：为实现无源光网络(PON)的平滑升级,提出了一种基于新型波长编码的标记率调制。该调制方法在下行信号传输中采用多个波长,在升级过程中,新PON信号通过选择一个特定波长进行调制,而旧PON信号则对编码后的新PON信号进行反向调制。通过相应的解码,可以从单独接收的光信号中恢复新PON信号。旧PON信号可以通过传统的幅度位移键控(ASK)直接接收。作为标记率调制,新PON信号和旧PON信号共享相同的光源和波长。相比于以前的基于时间编码的标记率调制,所提出的基于波长编码的标记率调制提供了更大的下行带宽,并且旧PON信号的比特率可以接近新的PON信号的比特率。经过升级,新PON的带宽可进一步扩展。对基于四波长编码的方案进行了演示和评估。结果表明,所提出的基于标记率调制的波长编码在PON平滑升级中是可行的。Objective Nowadays,passive optical networks(PONs)are the ultimate solution for optical access networks and have been deployed worldwide.To meet the rapidly increasing bandwidth demand,high-speed next-generation PONs are expected.PONs are cost-sensitive,and the main cost of a PON comes from constructing the optical distribution network(ODN),which can be up to 80%.Therefore,a smooth PON upgrade is highly desirable as it reuses the deployed ODN instead of rebuilding a new one.Since the new PON link shares the ODN with the legacy PON link,the coexistence of the two PON links with low crosstalk must be ensured.In the upstream direction,the new PON optical network units(ONUs)use an upstream wavelength different from that of the legacy PON ONUs,and the new PON upstream signal and the legacy PON upstream signal can be separated by a wavelength division multiplexer/demultiplexer(WDM)in the optical line terminator(OLT).The cost of adding one WDM in the OLT is acceptable.In the downstream direction,the separation(or filtering)should be in ONUs.The new ONUs have optical filters to filter out the legacy PON signal.However,the legacy ONUs have no optical filters to protect them from the new PON signal because they are designed with the coexistence in mind when they were installed.The retrofitting cost of adding one WDM to each legacy ONU is too high due to the large number and wide distribution of legacy ONUs.Thus,the crosstalk from the new PON downstream signal to the legacy PON downstream signal should be eliminated or reduced.Methods We utilize several wavelengths to construct a novel mark ratio modulation(MRM)based on wavelength coding for single-wavelength coexistence.The pulse position modulation(PPM)is transferred from the time domain to the wavelength domain,meaning that the pulse position is the“wavelength position”instead of the“time position”.The new PON signal is mapped to four sequences through the 4PPM coding method.Then,the legacy PON signal modulates the mark ratio of the four sequences by inverting the

关 键 词：无源光网络 平滑升级 标记率调制 波长补码 

分 类 号：O436[机械工程—光学工程]