Real-time Transmission of Geometrically-shaped Signals using a Software-defined GPU-based Optical Receiver

TL;DR

This paper presents a GPU-based software-defined optical receiver capable of real-time processing of high-order and geometrically shaped QAM signals over long-distance fiber links, demonstrating high data rates and detailed OSNR analysis.

Contribution

It introduces a novel GPU-implemented software receiver for real-time processing of complex geometrically shaped signals using KK detection, validated over a real-world optical fiber link.

Findings

Achieved 5 Gbps data rate with 64-QAM.

Successfully processed geometrically shaped 8- and 128-QAM signals.

Validated over 91 km field-deployed optical fiber link.

Abstract

A software-defined optical receiver is implemented on an off-the-shelf commercial graphics processing unit (GPU). The receiver provides real-time signal processing functionality to process 1 GBaud minimum phase (MP) 4-, 8-, 16-, 32-, 64-, 128-ary quadrature amplitude modulation (QAM) as well as geometrically shaped (GS) 8- and 128-QAM signals using Kramers-Kronig (KK) coherent detection. Experimental validation of this receiver over a 91~km field-deployed optical fiber link between two Tokyo locations is shown with detailed optical signal-to-noise ratio (OSNR) investigations. A net data rate of 5 Gbps using 64-QAM is demonstrated.