Low-PAPR interleaved single-carrier FDM scheme for optical wireless communications

As a potential complementary access technology for the 5G wireless systems, optical wireless communication (OWC) gains extensive attention for decades owing to its numerous advantages of broad license-free spectrum, immunity to electromagnetic interference and high-level privacy. However, two rigorous obstacles to achieve high data-rate OWC transmission are the severe nonlinear clipping of transmitter and high-frequency attenuation of OWC system. In this paper, we propose the first interleaved single-carrier frequency-division multiplexing (I-SC-FDM) scheme for OWC systems. Compared with orthogonal frequency-division multiplexing (OFDM), I-SC-FDM has a lower peak-to-average power ratio, which makes it more immune to the nonlinearity clipping in OWC systems. Meanwhile, for the bandwidth-limited OWC systems, I-SC-FDM has better performance on resistance to the serious high-frequency distortion. The simulation results indicate that, under the transmitter nonlinearity and optical-wireless diffuse fading channel, the maximum Q2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Q^2$$\end{document} of I-SC-FDM is about 3.44 dB and 3.14 dB higher than that of OFDM when 4-ary quadrature amplitude modulation (4-QAM) and 16-QAM are modulated, respectively. The results show the feasibility and advantages of I-SC-FDM for cost-sensitive OWC systems.