Abstract

DSP-enhanced intensity-modulation direct-detection (IM/DD) systems can support up to 56 Gb/s over 100 km signal transmissions at C-band. To achieve higher data rates and longer transmission distances, we propose data-aided iterative algorithm (DIA) and decision-directed DIA (DD-DIA) to digitally mitigate signal-signal beating interference (SSBI) without requiring any modifications to physical layer structures. DIA utilizes pilot symbols with uniformly spaced insertions to relax the modified Gerchberg-Saxton (G-S) algorithms that suffer from the local optimum problem. To further improve the symbol error rate (SER) performance and convergence speed, DD-DIA introduces a decision process to generate pseudo-pilots. We numerically compare DIA with other algorithms and find that DIA can recover signals subject to large fiber dispersions corresponding to which conventional IA and Volterra filter (VF) fail, while DD-DIA significantly accelerates the convergence speed and improves the reconstruction performance compared with DIA, it can support 100-Gb/s PAM4 over 400-km IM/DD transmissions within just 50 iterations. Two orders of magnitude reductions in SER is observed for 100 Gb/s PAM4 signal transmission over 100-km SSMFs. Compared with conventional IA, the proposed techniques have higher convergence speeds, better global optimum features and large tolerances to physical model errors. In particular, DD-DIA results in larger optical signal-to-noise ratio (OSNR)/ received optical power (ROP) improvement, higher transmission capacities and less computational complexity. DD-DIA is a promising algorithm for efficiently reconstructing 2-dimensional optical field for conventional IM/DD optical transmission systems.

Multi-constraint Gerchberg-Saxton iteration algorithms for linearizing IM/DD transmission systems

Shaohua Hu, Jing Zhang, Jianming Tang, Taowei Jin, Wei Jin, Qun Liu, Zhuqiang Zhong, Roger Giddings, Yanhua Hong, Bo Xu, Xingwen Yi, and Kun Qiu
Opt. Express 30(6) 10019-10031 (2022)

Experimental demonstration of pre-electronic dispersion compensation in IM/DD systems using an iterative algorithm

Xiong Wu, Abdullah S. Karar, Kangping Zhong, Alan Pak Tao Lau, and Chao Lu
Opt. Express 29(16) 24735-24749 (2021)

Complexity curtailed MLSE equalizer based on a compact look-up-table for C-band DSB IM/DD transmission

Zhuo Chen, Xiaoxiao Dai, Junyuan Nie, Shenmao Zhang, Jiahao Zhou, Jing Zhang, Ying Qiu, Ming Luo, Qi Yang, Lei Deng, Mengfan Cheng, Kun Qiu, and Deming Liu
Opt. Lett. 47(21) 5606-5609 (2022)

Pairwise Tomlinson-Harashima precoding for multiple-lane IM-DD transmissions

Meng Xiang, Yongfeng Qiu, Can Wei, Gai Zhou, Jilong Li, Cong Zhang, Jianping Li, Songnian Fu, and Yuwen Qin
Opt. Express 32(6) 9245-9254 (2024)

Augmented space signal detection method for IM/DD optical communication systems

Yunfeng Gao, Chuanchuan Yang, Xiaoyu Zhang, Cheng Zhang, and Hongbin Li
Opt. Lett. 47(16) 4147-4150 (2022)