The Spatial Dimming Scheme for the MU-MIMO-OFDM VLC System

IEEE Photonics Journal

Caili Guo¹  Yang Yang²  Zhen Feng²  Zabih Ghassemlooy³ 

[1] Beijing Key Laboratory of Network System Architecture and Convergence, School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing, China;Beijing Laboratory of Advanced Information Networks, School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing, China;Optical Communications Research Group, NCRLab, Faculty of Engineering and Environment, Northumbria University, Newcastle-upon-Tyne, U.K.;

关键词: Visible light communication (VLC);    dimming control;    multiple-input multiple-output (MIMO);    orthogonal frequency-division multiplexing (OFDM);    multiuser.;   

DOI  :  10.1109/JPHOT.2018.2866706

来源: DOAJ

【 摘 要 】

Multiuser visible light communication (MU-VLC) systems utilizing multiple-input multiple-output (MIMO) and orthogonal frequency-division multiplexing (OFDM) are gaining increased attentions recently. Visible light communication (VLC) links are expected to work under different illumination conditions and, thus, the need for dimming control mechanisms. However, the traditional analog- and digital-based dimming schemes have adverse effects on the data communications performance, such as clipping distortion and the variation of the duty cycle. In this paper, spatial dimming schemes based on the zero-forcing and the minimum mean-squared error precoding schemes are proposed for direct-current biased optical OFDM based indoor MU-MIMO VLC system, and the bipolar optical OFDM signal is biased by a fixed dc level. Transmit antenna selection algorithms are designed for the optimum working light emitting diodes (LEDs) subset at each dimming level. Owing to the simultaneously exploration of the selection diversity of LEDs-based lights and the channel state information, the proposed spatial dimming schemes outperform the traditional dimming schemes, which is also verified by simulation results. Thus, the proposed schemes are shown to have a great potential to be applied in practical MU-MIMO-OFDM VLC systems.

【 授权许可】

Unknown