Driven by the tremendous need of transmission capacity in future optical communication networks, the project aims to study theoretically and experimentally novel solutions to improve 100-Gb/s systems based on QPSK modulation and polarization-division multiplexing, in case of DSP-aided processing and coherent detection. Coherent detection represents a new fundamental breakthrough, moving the complexity of communication system at the DSP unit.
The goal of the project is to explore novel technical solutions for 100-Gb/s and beyond optical fiber transmission with very high spectral efficiency. Advanced multilevel modulation formats and densely-packed multiplexing techniques will be optimized in order to reduce nonlinear limitations in WDM propagation and to enhance system performance and transmission reach. New DSP algorithms will be employed for carrier phase recovery and for compensation of linear fiber propagation impairments.
The study of high-order multilevel modulation formats combined with multiplexing techniques, synchronization algorithms and improved coding/decoding, relying on DSP-aided processing and coherent detection, can be considered the very challenging research topics for next-generation optical networks. Modulation formats such as 16-QAM, 64-QAM, and 256-QAM will be considered with the objective of raising the capacity of the 50 GHz spaced channel up to 400 Gb/s.Data converters operating at dozens of Gsamples/s are today available. This technological step has emphasized the role of high-speed optoelectronic processing of the signal in the development of coherent optical transmission systems. After some years at research stage, 100Gb/s systems will be soon commercially available in the next future. Thanks to our research, their improvement in terms of performance, transmission reach, complexity and cost will be possible. Moreover, solutions for 200-Gb/s and beyond transmission will be made realistic and their feasibility will be demonstrated.