摘要
硅基调制器具有体积小、功耗低、易集成等优势,但相较于铌酸锂调制器,线性度通常较差,从而限制了其在光载无线等通信系统中的性能。提出一种增强型最大比例混合接收机(EMRC-Rx),用以补偿硅基调制器对无源光接入网络带来的性能下降缺点。EMRC-Rx综合利用直接检测机(DD-Rx)和轻相干检测机(Lite CO-Rx)的优势,借助两种接收方式的最大信噪比占比,可以显著提升接收机的灵敏度,进而解决硅基调制器低线性度导致的系统性能下降问题。实验结果表明,当误码率高于KP4-FEC阈值1.0×10^(-4)时,相较于DD-Rx和Lite CO-Rx,EMRC-Rx的接收灵敏度分别提升5.5 dB和8.8 dB,误差矢量幅度(EVM)分别提升32.5%和41.1%,系统性能明显得到改善。通过进一步与铌酸锂调制器进行对比发现,相比采用铌酸锂调制器的Lite CO-Rx和DD-Rx,基于硅基调制器的EMRC-Rx的接收灵敏度分别提升3.5 dB和7.9 dB,且可取得与铌酸锂调制器中MRC-Rx接近的系统性能,验证了EMRC-Rx对硅基调制器低线性度带入的性能劣化的补偿效果。本工作对在5G时代利用硅基调制器构建高可靠、低成本的光子集成接入网具有指导意义。
Objective Silicon-based modulators feature small size,low power consumption,and easy integration.However,compared with lithium niobate modulators,they suffer poor linearity,which limits their performance in analog communication systems such as radio over fiber access networks.Various improvement methods have been proposed to improve the linearity of silicon-based modulators,including optimizing the p-n junction design,modifying the doping concentration of the p-n junction,and adopting novel waveguide structures,electrode structures,and driving methods.However,these methods generally require altering the physical characteristics or structures of the devices or adding additional driving circuits.The modulator linearity is typically fixed once the device fabrication or packaging is completed,which makes it difficult to change afterward.Currently,there is a lack of compensation schemes for Si modulator linearity after device fabrication or packaging.Therefore,we want to propose a way from the system perspective to conduct the performance compensation caused by the poor linearity of Si modulators.Methods In our paper,a novel enhanced maximum-ratio combined receiver(EMRC-Rx)is proposed and demonstrated through proof-of-concept experiments,and it is conducted to mitigate the system performance degradation caused by the low linearity of Si modulators when the modulators are deployed in passive optical network(PON)-based access networks.The EMRC-Rx leverages the advantages of both direct detection receiver(DD-Rx)and lite coherent detection receiver(Lite CO-Rx)by utilizing the maximum signal-to-noise ratio contribution from both the receiver types to significantly improve receiver sensitivity and mitigate the system performance degradation.The proposed EMRC algorithm considers the contribution of multiple Lite CO-Rx components to the output signal-to-noise ratio,thereby increasing the proportion of signal-to-noise ratio in the lite coherent receiver and further enhancing the receiver sensitivity.As a result,the EMRC-Rx in
作者
秦军
陶源盛
金明
韩昌灏
Rahul Kumar Gangwar
李月琴
孙剑
缪旻
Qin Jun;Tao Yuansheng;Jin Ming;Han Changhao;Gangwar Rahul Kumar;Li Yueqin;Sun Jian;Miao Min(Key Laboratory of Information and Communication Systems,Ministry of Information Industry,School of Information&Communication Engineering,Beijing Information Science&Technology University,Beijing 100101,China;Key Laboratory of Optoelectronic Measurement Technology and Instrument,Ministry of Education,School of Information&Communication Engineering,Beijing Information Science&Technology University,Beijing 100101,China;State Key Laboratory of Advanced Optical Communication Systems and Networks,School of Electronics,Peking University,Beijing 100871,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2023年第23期118-129,共12页
Acta Optica Sinica
基金
国家自然科学基金(62001010,62105037)
北京大学区域光纤网与新型光通信系统国家重点实验室开放课题(2022GZKF016)。
关键词
硅基调制器
直接检测
轻相干检测
无源光接入网
调制器线性度
silicon-based modulator
direct detection
lite coherent detection
passive optical access network
modulator linearity
