KDDI Research, Inc. Print

A New Record of 2048-QAM Transmission over Optical Fiber with COTS Devices

June 29, 2021
KDDI Research, Inc.

KDDI Research and a research group, TRANSNET (*1) , from University College London (UCL) introduced geometric constellation shaping based on an optimization used in machine learning for minimizing the transmission error, and collaboratively demonstrated 2048-QAM (*2) transmission (16.9 bit/symbol (*3) ) over a 100-km optical fiber with only COTS (commercial off-the-shelf) devices. This is the highest-order optical fiber transmission with the geometric constellation shaping demonstrated to date.


The high-order modulation formats in combination with geometric constellation shaping are expected to become one of the key technologies for ultra-high speed optical transceivers in data-center interconnection, mobile backhaul etc.


The research has been published in an open-access journal, Optics Express.


Title: 2048-QAM transmission at 15 GBd over 100 km using geometric constellation shaping
Authors: Yuta Wakayama (KDDI Research), Thomas Gerard, Eric Sillekens, Lídia Galdino, Domaniç Lavery, Robert I. Killey, and Polina Bayvel (UCL)



*1 TRANSNET is a research project led by University College London (UCL) in collaboration with Aston University and University of Cambridge aiming at creating an adaptive intelligent optical network.
*2 2048 QAM is a modulation format, which can express individual 2048 states by modulating optical amplitude and phase.
*3 bit/symbol is a unit to describe the amount of information per modulation.



※The information contained in the articles is current at the time of publication.Products, service fees, service content and specifications, contact information, and other details are subject to change without notice.