Abstract

Rapid increase of data-center traffic due to the growing use of cloud services and mobile broadband services requires a higher capacity Ethernet link based on an economical approach and high-performance short-reach optical transmission techniques based on intensity-modulation and direct-detection have been attracting huge interest. In the next-generation Ethernet such as 800GbE or 1.6TbE, a higher-baudrate signal will be necessary and the transmission performance will be limited by the transceiver bandwidth. In this article, we show a spectral-shaping technique for PAM signals based on a nonlinear differential coding which realizes the narrower signal spectrum and enhances the tolerance to bandwidth limitation. We theoretically investigate the characteristics of the proposed scheme and demonstrate 186-Gb/s 10-km transmission by means of an O-band experiment with a 3-dB bandwidth of 14 GHz in which the proposed technique is applied to a 93-Gbaud PAM4 signal. Furthermore, we propose a combination of nonlinear differential coding and LLR-based decoding and show that the combined scheme realizes 4-dB improvement in the required optical power. We also investigate the performance dependency on the parameters such as the number of taps in the equalizers utilized in the decoder.

Polar coded probabilistic shaping PAM8 based on many-to-one mapping for short-reach optical interconnection

Honghang Zhou, Yan Li, Xiaoshuo Jia, Chao Gao, Yuyang Liu, Jifang Qiu, Xiaobin Hong, Hongxiang Guo, Yong Zuo, and Jian Wu
Opt. Express 29(7) 10209-10220 (2021)

Single-lane 180  Gbit/s PAM-4 signal transmission over 2  km SSMF for short-reach applications

Qiang Zhang, Nebojsa Stojanovic, Cristian Prodaniuc, Changsong Xie, Michael Koenigsmann, and Piotr Laskowski
Opt. Lett. 41(19) 4449-4452 (2016)

Experimental study of PAM-4, CAP-16, and DMT for 100 Gb/s Short Reach Optical Transmission Systems

Kangping Zhong, Xian Zhou, Tao Gui, Li Tao, Yuliang Gao, Wei Chen, Jiangwei Man, Li Zeng, Alan Pak Tao Lau, and Chao Lu
Opt. Express 23(2) 1176-1189 (2015)

Optical amplification-free deep reservoir computing-assisted high-baudrate short-reach communication

Mengyao Han, Muguang Wang, Yuchuan Fan, Toms Salgals, Hadrien Louchet, Richard Schatz, Markus Gruen, Fabio Pittala, Benjamin Krüger, Thomas Dippon, Lu Zhang, Xianbin Yu, Sandis Spolitis, Vjaceslavs Bobrovs, Sergei Popov, Xiaodan Pang, and Oskars Ozolins
Opt. Lett. 48(8) 2122-2125 (2023)

Improved polar decoding for optical PAM transmission via non-identical Gaussian distribution based LLR estimation

Honghang Zhou, Yan Li, Tao Dong, Jifang Qiu, Xiaobin Hong, Hongxiang Guo, Yong Zuo, Jie Yin, Yuwei Su, and Jian Wu
Opt. Express 28(26) 38456-38464 (2020)