Open AccessOn the benefit of DMT modulation in nonlinear VLC systems
Author(s) -
Hua Qian,
Shuzhen Cai,
Saijie Yao,
Ting Zhou,
Yang Yang,
Xudong Wang
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.002618
Subject(s) - visible light communication , pulse amplitude modulation , modulation (music) , nonlinear distortion , intensity modulation , optics , quadrature amplitude modulation , distortion (music) , transmitter , pulse density modulation , amplitude modulation , nonlinear system , analog transmission , delta modulation , signal (programming language) , physics , computer science , telecommunications , phase modulation , frequency modulation , bit error rate , pulse (music) , light emitting diode , bandwidth (computing) , acoustics , phase noise , amplifier , detector , digital signal , transmission (telecommunications) , channel (broadcasting) , quantum mechanics , programming language
In a visible light communication (VLC) system, the nonlinear characteristic of the light emitting diode (LED) in transmitter is a limiting factor of system performance. Modern modulation signals with large peak-to-power-ratio (PAPR) suffers uneven distortion. The nonlinear response directly impacts the intensity modulation and direct detection VLC system with pulse-amplitude modulation (PAM). The amplitude of the PAM signal is distorted unevenly and large signal is vulnerable to noise. Orthogonal linear transformations, such as discrete multi-tone (DMT) modulation, can spread the nonlinear effects evenly to each data symbol, thus perform better than PAM signals. In this paper, we provide theoretical analysis on the benefit of DMT modulation in nonlinear VLC system. We show that the DMT modulation is a better choice than the PAM modulation for the VLC system as the DMT modulation is more robust against nonlinearity. We also show that the post-distortion nonlinear elimination method, which is applied at the receiver, can be a reliable solution to the nonlinear VLC system. Simulation results show that the post-distortion greatly improves the system performance for the DMT modulation.