Advanced Signal Processing for High-speed Optical Fiber Systems

Most installed Ethernet backbones based on multi-mode fibers operate at bit rate of about 1Gb/s, which is inadequate for current and emerging demands. With the advent of high-speed (40 Gb/s and beyond) fiber optic transmission systems, advanced signal processing and coding schemes for such systems should be carefully designed and optimized in a principled way. Traditionally, optical systems perform a minimal amount of signal processing. Owing to advances in technology, today it is possible to perform sophisticated signal processing functions in optical systems. This could bring enormous flexibility resulting from the opportunity to employ low-cost and adaptive signal processing circuits that is not practical in the optical domain. This project focuses on the development of new design paradigm and advanced algorithms for high-speed fiber optic systems. In particular, it encompasses in-depth investigations on the design of coded modulation schemes, high-speed decoding algorithms, and highly efficient multi-carrier transmission techniques, for very-high speed optical communications. A large arsenal of digital and statistical signal processing tools will be explored, including coset codes, dense lattices, frame theory, and Monte Carlo signal processing. In addition to conducting theoretical analysis, computational procedures will be developed to facilitate the analytical work. The new concepts and algorithms developed under ideal conditions will be tailored to operate in practical systems with various constraints. It is expected that the proposed research will not only enhance our understanding of the fundamental underpinnings of complex fiber optic systems and develop novel signal processing concepts and methods, but also produce new and powerful tools for physical layer solutions for future high-speed optical systems.