Digital Signal Processing Techniques Enabling Multi-Tb/s Superchannel Transmission

Digital signal processing combined with coherent detection has played a central role in the recent capacity expansion of optical networks. Optical superchannels aim to increase per-channel interface rates as well as per-fiber capacities of wavelength-division multiplexed (WDM) systems in a cost-effective manner. Superchannels circumvent the electronic bottleneck via optical parallelism, and provide high per-channel data rates and better spectral utilization, especially in transparent optical mesh networks. This paper reviews recent advances in the generation, detection, and transmission of optical superchannels with channel data rates on the order of Terabits/s. Enabling digital signal processing techniques such as Nyquist-WDM, orthogonal-frequency-division-multiplexing (OFDM), software-defined modulation and detection, advanced coding, and joint digital signal processing (DSP) among the superchannel constituents are presented. Future prospects of DSP techniques for high-capacity superchannel transmission are also discussed.