Improved SD-FEC with multi-tap error-tracking DFE with partial unrolling in high-speed IM/DD systems  

作　　者：Xue Zhao Jing Zhang Jiahao Zhou Chenye Wang Zhengyu Ma Shaohua Hu Bo Xu Kun Qiu 赵雪;张静;周家豪;王晨烨;马正雨;胡少华;许渤;邱昆

机构地区：[1]Key Laboratory of Optical Fiber Sensing and Communications(Ministry of Education),School of Communication and Information Engineering,University of Electronic Science and Technology of China,Chengdu 611731,China

出　　处：《Chinese Optics Letters》2025年第1期25-30,共6页中国光学快报(英文版)

基　　金：supported by the National Natural Science Foundation of China(Nos.62301128 and U22A2086);the STCSM(No.SKLSFO2021-01);the Open Fund of IPOC(BUPT)(No.IPOC2020A011);the Fundamental Research Funds for the Central Universities(Nos.ZYGX2020ZB043 and ZYGX2019J008)。

摘　　要：We propose a multi-tap look-up-table(LUT)-based error-tracking decision feedback equalizer with partial unrolling(ET-DFEPU)algorithm to improve log-likelihood ratio(LLR)quality with error propagation.We introduce an error-tracking model to obtain the probabilities of different error states,which are input into the decoder to obtain more accurate LLRs.We also use LUTs to reduce the computation complexity of ET-DFE-PU.Moreover,we adopt a low-complexity partially unrolled architecture to relax the feedback timing constraint.We conduct experiments to transmit 170-Gb/s 4-ary pulse amplitude modulation signal in intensity modulation and direct-detection system at C-band.The results show that the proposed method can achieve 3-d B receiver sensitivity improvement at the same post-forward error correction bit error ratio compared with the conventional DFE.

关 键 词：decision feedback equalizer error propagation tracking look-up table log-likelihood ratio intensity modulation and direct detection 

分 类 号：TN911.2[电子电信—通信与信息系统]