Single- and multi-carrier techniques to build up Tb/s per channel transmission systems

In this paper, we review emerging technologies to build up Tb/s per channel transmission capacity. The different approaches, mainly based on various implementations of orthogonal frequency division multiplexing, Nyquist wavelength division multiplexing and optical time division multiplexing, are introduced and compared with respect to complexity, spectral efficiency and transmission reach. In addition to this analysis, we review recent Tb/s per channel transmission experiments, which have employed at least one of these techniques, and compare them to conventional WDM systems.