Advanced Digital Signal Processing Techniques for High-Speed Optical Communications Links

TL;DR

This thesis proposed a novel bi-directional architecture for <2km Intra-DC link and a detailed analysis of self-coherent single-sideband transmission for <80km dispersion-uncompensated Inter- DC link.

Abstract

The main topic of this thesis is the application of advanced Digital Signal Processing (DSP) techniques to high data-rate optical links. This thesis is divided in two parts: Direct-Detection systems, and Coherent systems. In the first part, it is proposed a novel bi-directional architecture for <2km Intra-DC link and a detailed analysis of self-coherent single-sideband transmission for <80km dispersion-uncompensated Inter-DC link. The second part instead focuses on Probabilistic Constellation Shaping techniques, and their impact on long-haul optical communication links.

Figures (60)

• Figure 1: Evolution of Ethernet interfaces data-rate (a) and current form factors (b). Power consumption of a form factor is approximately proportional to its top surface. Source: Ethernet Alliance.
• Figure 2: Basic block scheme of the 400GBASE-FR8 standard, based on 8 WDM channels, each modulated with 50 Gbit/s PAM-4. For simplicity, the diagram shows transmission on a single direction.
• Figure 3: Maximum chromatic dispersion of G.652.B optical fiber (SMF) in the O-band.
• Figure 4: Power levels of a PAM-$M$ transmission with the definition of outer OMA.
• Figure 5: Bit Error Ratio of different PAM modulation formats as a function of the outer OMA.