Spectral-efficient IM-DD transmissions using a super-Nyquist subcarrier modulation

We propose a flexible bandwidth compression scheme for Intensity-Modulation and Direct-Detection (IM-DD) transmissions employing the Super-Nyquist Subcarrier Modulation (SN-SCM) signal. After transmitting a 25 Gbaud 16QAM SN-SCM signal over 2 km Standard Single-Mode Fiber (SSMF), 14.7% Spectral Efficiency (SE) enhancement is guaranteed with the help of the Decision-Feedback-Equalization with Multiple-Input-Multiple-Output structure (DFE_MIMO) for Inter-Subcarrier-Interference (ICI) mitigation.