Techniques for Mitigating the Effects of Transmission Impairments in Single-Mode Digital Fiber Optic Systems.

This memorandum is intended as a roadmap for selecting signal processing techniques that reduce the effects of transmission impairments, and thereby provide higher data rates, improved error rates, or longer repeaterless spans, in both direct and coherent detection single-mode fiber optic systems. These techniques include multilevel signaling, interference reduction techniques such as equalization, and coding for lightwave systems. We discuss the major transmission impairments in lightwave systems and the various techniques that can be used to overcome these impairments. General guidelines are presented that can be used to decide which techniques are most appropriate in reducing specific impairments and to estimate the expected improvements that can be obtained. We also describe potential application of these techniques to long-haul, local-area, and local loop systems.