Reconstructed Hybrid Optical OFDM-NOMA for Multiuser VLC Systems

Non-orthogonal multiple access (NOMA) is deemed to be a prospective technology of the next generation. However, in visible light communication (VLC), when advanced hybrid optical orthogonal frequency division multiplexing (O-OFDM), such as asymmetrically clipped O-OFDM (HACO-OFDM), combined with NOMA, error propagation induced, which degrades system performance. Therefore, novel reconstructed O-OFDM-NOMA (RHO-OFDM-NOMA) scheme conceived this paper. In order eliminate propagation, users RHO-OFDM-NOMA opt for ACO-OFDM or clipping-free signals according their channel qualities, are subsequently superimposed on pulse-amplitude-modulated discrete multitone (PAM-DMT) yield spectrum-efficient signal. Furthermore, reconstruction process designed ensure non-negativity. Compared HACO-OFDM, proposed RHO-OFDM can retain NOMA-VLC, whilst maintaining superiorities high spectral and power efficiency. It demonstrated by simulation results that support notably higher data rate than NOMA schemes using conventional O-OFDM.