PhD defence by Rasmus Thomas Jones

Title: Machine Learning Methods in Coherent Optical Communication Systems


Main supervisor: Assoc. Prof. Darko Zibar, DTU Fotonik
Co-supervisor: Dr. Metodi Yankov, DTU Fotonik

Evaluation Board

Prof. Søren Forchhammer, DTU Fotonik
Assoc. Prof. Andrea Carena, Politecnico di Torino, Italy
Assist. Prof. Chigo Okonkwo, Eindhoven University of Technology, The Netherlands

Master of the Ceremony

Assoc. Prof. Michael Galili


The future demand for digital information will outpace the capabilities of current optical communication systems, which are approaching their limits due to fiber intrinsic nonlinear effects. Machine learning methods promise to find new ways of exploiting the available resources, and to handle future challenges in larger and more complex systems.

The methods presented in this work apply machine learning on optical communication systems:

A machine learning framework combines dimension reduction and supervised learning, addressing computational expensive steps of fiber channel models. The trained algorithm allows more efficient execution of the models.

Supervised learning is combined with a mathematical technique, the the nonlinear Fourier transform, realizing more accurate detection of high-order solitons. During transmission a non-deterministic impairment from fiber loss and amplification noise, lead to distorted solitons. A machine learning algorithm is trained to detect the solitons despite the distortions and outperforms the standard receiver.

An unsupervised learning algorithm with embedded fiber channel model is trained end-to-end, learning a geometric constellation shape that mitigates nonlinear effects. In simulation and experimental studies, the learned constellations yield improved performance to state-of-the-art geometrically shaped constellations.


The contributions demonstrate, that machine learning is a viable tool for increasing the capabilities of optical communications systems.


man 17 dec 18
13:30 - 16:30


DTU Fotonik


Lyngby Campus

Bld. 341, aud. 23