From Constellation Shaping to Nonlinear Fourier Transform – On the Way to the Limits of Optical Data Links!?
29.10.2018 von 17:15 bis 18:00
Within a decade, coherent detection together with digital signal processing pushed optical long-haul transmission (some 100 km up to some 1000 km) close to the theoretical capacity limit (Shannon limit) of the fiber. Remaining challenges are the limitation posed by the nonlinearity of the fiber channel (Kerr effect) and transponder concepts allowing for seamless tuning of the bit-rate to the actual capacity of the fiber. In the last years the growing number and size of data centers moved the focus of research also to short-reach links (100 km and below) with more pronounced requirements related to power efficiency, complexity and costs.
Experimental results of Nokia Bell Labs in Stuttgart will be presented which cover some of these topics. We will have a closer look at (1.) smooth constellation shaping in coherent systems, (2.) so called nonlinear modulation formats based on nonlinear Fourier transform, (3.) direct detection system concepts such as Tomlinson-Harashima pre-coding, artificial neural network-based pre and post-equalization, as well as the Kramers-Kronig scheme for mobile fronthaul.
Henning Bülow is a distinguished member of technical staff (DMTS) at Nokia Bell Labs in Stuttgart, Germany. He received his Dipl.-Ing. degree in electrical engineering from the University of Dortmund, Germany, and a Dr.-Ing. degree in electrical engineering from the University of Berlin for work on integrated optical switching matrices. During his more than two decades tenure with Nokia Bell Labs, he has worked on different topics of optical communication ranging from erbium-doped fiber amplifiers, over dynamic mitigation of transmission impairments by electronic, optical and digital signal processing, to 4-D modulation and mode multiplexing. From 2008 to 2011 he served as Guest Professor with the University of Erlangen-Nuremberg. He is now leading a research department of the Smart Network Fabric Research Lab of Nokia Bell Labs. He is member of the VDE/ITG-Fachausschuss 5.3 „Optische Nachrichtentechnik“ and of the technical program committee of the European Conference on Optical Communication (ECOC).