Low-complexity sparse absolute-term based nonlinear equalizer for C-band IM/DD systems

Junwei Zhang, Zhenrui Lin, Xiong Wu, Jie Liu, Alan Pak Tao Lau, Changjian Guo, Chao Lu, Siyuan Yu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

A low-complexity sparse absolute-term based nonlinear equalizer (AT-NLE) is proposed to eliminate the nonlinear signal distortions for intensity modulation and direct detection (IM/DD) systems. By performing the orthogonal matching pursuit (OMP) algorithm to adaptively obtain the significant kernels of both the linear and absolute terms, the computational complexity of the proposed sparse AT-NLE is dramatically reduced and independent of the memory length. The performance of the proposed sparse AT-NLE is experimentally evaluated in a C-band 56-Gbit/s four-level pulse-amplitude modulation (PAM-4) system over a 30-km standard single-mode fiber (SSMF). Experimental results show that compared with the conventional diagonally-pruned Volterra nonlinear equalizer (DP-VNLE) or DP-AT-NLE, the proposed sparse AT-NLE saves 77.7% or 76% real-valued multiplications when their achieved bit error ratios (BERs) are similar. Meanwhile, the proposed sparse AT-NLE reduces the computational complexity by > 28% compared to the sparse DP-VNLE at a BER of 5 × 10−4. The proposed low-complexity sparse AT-NLE shows great potential for high-performance and low-cost IM/DD optical transmission systems.

Original languageEnglish
Pages (from-to)21891-21901
Number of pages11
JournalOptics Express
Volume29
Issue number14
DOIs
Publication statusPublished - 5 Jul 2021

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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