Real-time demonstration of adaptive constellation shaping for intelligent optical networks on NDFF

Constellation shaping was dynamically updated based on the measured accumulated noise in the system. The OFC attendees can choose the fibre links length (from 40km to 450km) and see real-time updates of constellation diagrams adapted to the selected route.

The real-time performance of an adaptive intelligent transceiver was demonstrated at OFC 2023 on 6^th March, Figure 1. This demo showed the performance of first adaptive geometric shaper which responds to the received signal and updates real-time constellation used by the transceiver in real-time, maximising the general mutual information (GMI). The configuration of the constellation points is updated based on the received signal after transmitting via 450 km dark fibre facility.

Figure 1: Real-time demonstration of adaptive constellation shaping to OFC attendees.

In the demonstration, GPU was used to implement the constellation optimisation in hardware. The GPU was connected to a laptop and an external display. Laptop was used to take user input and as an Ethernet bridge to enable communication to the UCL lab and the transmission equipment, including remotely-reconfigurable transceiver which transmits sequences over software configurable NDFF testbed. Figure 2 shows the simplified experiment diagram.

Figure 2: Simplified overall system diagram.

Published: 23 March 2023