Experimental comparison of 56 Gbit/s PAM-4 and DMT for data center interconnect applications

Nicklas Eiselt, Annika Dochhan, Helmut Griesser, Michael Eiselt, Juan José Vegas Olmos, Idelfonso Tafur Monroy

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

2 Citations (Scopus)


Four-level pulse amplitude modulation (PAM-4) and discrete multi-tone transmission (DMT) in combination with inten-sity modulation and direct-detection are two promising approaches for a low-power and low-cost solution for the next generation of data center interconnect applications. We experimentally investigate and compare both modulation formats at a data rate of 56 Gb/s and a transmission wavelength of 1544 nm using the same experimental setup. We show that PAM-4 outperforms double sideband DMT and also vestigial sideband DMT for the optical back-to-back (b2b) case and also for a transmission distance of 80 km SSMF in terms of required OSNR at a FEC-threshold of 3.8e-3. However, it is also pointed out that both versions of DMT do not require any optical dispersion compensation to transmit over 80 km SSMF while this is essential for PAM-4. Thus, implementation effort and cost may be lower for DMT. Furthermore, the dispersion tolerance of PAM-4 in dependence of a feedforward equalizer (FFE) is investigated.
Original languageEnglish
Title of host publicationPhotonic Networks; 17. ITG-Symposium; Proceedings of
PublisherVDE Verlag
Number of pages5
ISBN (Print)978-3-8007-4219-6
Publication statusPublished - 2016
Externally publishedYes
EventPhotonic Networks ITG-Symposium - Leipzig, Germany
Duration: 12 May 201613 May 2016


ConferencePhotonic Networks ITG-Symposium


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