A low PAPR multicarrier and multiple access schemes for VLC

Abstract

The omnipresence of solid-state illuminating devices like Light Emitting Diodes (LEDs) has driven Visible Light Communication (VLC) to acquire mammoth eminence. However, the limited dynamic range of LEDs leads to deleterious non-linear distortion when employing the high data rate multicarrier modulation technique like optical orthogonal frequency division multiplexing (OOFDM) resulting in high Peak to Average Power Ratio (PAPR). Furthermore, since VLC has profound applicability in a cellular network, there is an urge to investigate different PAPR mitigation techniques. In this paper, Discrete Cosine Transform-Spread-Fast-Optical OFDM (DCT-S-FOOFDM) is proposed and compared with other PAPR reduction schemes like Partial Transmit Sequence (PTS), clipping and filtering techniques. This work focuses on imparting Discrete Fourier Transform (DFT)-spreading for Optical Orthogonal Frequency Division Multiple Access (OOFDMA) and DCT-spreading for Fast Optical Orthogonal Frequency Division Multiple Access (FOOFDMA) system to reduce PAPR. Here, an elaborate mathematical analysis of the time-domain signal is accomplished for Asymmetrically clipped DC biased-Optical-Interleaved FDMA (ADO-IFDMA), Asymmetrically clipped-Optical-Localized FDMA (ACO-LFDMA), Fast-Optical-IFDMA (F-O-IFDMA) and Fast-Optical-LFDMA (F-O-LFDMA). The simulated result analysis emphasizes that PAPR is reduced significantly by employing DCT-Spreading in FOOFDM. Among the multiple access schemes, PAPR reduction in F-O-IFDMA is superior than F-O-LFDMA and outperforms FOOFDMA.