A Robust Channel Processor for Faster-than-Nyquist Non-Orthogonal FDM Visible Light Communication Systems

We propose and experimentally characterize a modified fractional DFT matrix and a robust channel processor for FTN-NOFDM visible light communication systems without complex upconversion. A 1.76-Gb/s FTN-NOFDM signal with 20% reduced bandwidth achieves ∼6-dB sensitivity improvement over 2-m free-space transmission.