Next-Generation Optical Communication Systems:

A New Frontier for Advanced Digital Signal Processing

Abstract

In the next generation of long-haul fiber-optic communication systems, it is envisioned that a single wavelength will support 100+ Gb/s transmission rates via migration to advanced modulation and detection formats that will increase both spectral efficiency and optical impairment tolerance. Most recently, multi-level constellations combined with polarization multiplexing and digital coherent detection (coherent optical detection followed by electronic digital signal processing) have emerged as the most promising approach to realize this goal. Advanced electronic DSP thus continues to be reinforced as a critical component of future optical communication systems, without which no single-channel 100+ Gb/s scheme can remain practical. In this talk, this prominent role of DSP will be highlighted from both the modulation and detection perspectives. In terms of advanced modulation, trade-offs between single-carrier (QPSK, 8PSK) and multi-carrier (OFDM) polarization-multiplexed transmission will be addressed.  The structure of a digital coherent receiver will also be discussed, with particular focus on DSP-enabled polarization de-multiplexing, optical dispersion compensation, and carrier phase recovery. Some of our recent experimental results that exploit these techniques to realize 17 Tb/s (161x114 Gb/s) transmission over 660 km will likewise be presented. Finally, the talk will conclude with some open questions on this topic, including DSP-based nonlinearity compensation in fiber and its implications to the on-going quest for the fundamental (Shannon) capacity of the fiber-optic channel.

Biography

Neda Cvijetic received the B.S. (summa cum laude), M.S. and Ph.D. degrees in electrical engineering from the University of Virginia in 2004, 2005, and 2008, respectively. She is currently a Research Staff Member in the Broadband and Mobile Networking Department at NEC Laboratories, Princeton, NJ. Her research interests include advanced modulation/detection techniques for high-speed optical transmission, optical-wireless convergence, and throughput optimization in heterogeneous networks.