Comparison of Time Domain Hybrid PAM and DMT for Data Center Applications

In this publication, we investigate and compare two approaches for flexible transmission systems with intensity modulation and direct detection for inter data center communications, namely discrete multi-tone and time domain hybrid pulse amplitude modulation. Both transmission approaches were used to vary the data rate between 56 and 112 Gb/s with fine granularity. Vestigial side-band transmission was used in order to avoid the power fading effect. Inter-symbol interference due to chromatic dispersion was compensated using digital signal processing at the receiver side. In an experimental verification of the DMT setup, we successfully transmitted 56 Gb/s over 150 km SSMF without in-line amplification.