Dual-Codeword Allocation Scheme for Dimmable Visible Light Communications

Author

Youngsuk Suh ; Chang-Hoi Ahn ; Jae Kyun Kwon

Author_Institution

LED-IT Fusion Technol. Res. Center, Yeungnam Univ., Gyeongsan, South Korea

Volume

25

Issue

13

fYear

2013

fDate

1-Jul-13

Firstpage

1274

Lastpage

1277

Abstract

This letter proposes a practical scheme for LED dimming control in visible light communications (VLC). The scheme entails the allocation of a set of codewords to a symbol. Here, the set is usually composed of two codewords with different average intensities. For dimming control, one of two codewords is selectively transmitted and the dimming control capability of the proposed scheme increases when the symbol distribution is not uniform. The proposed VLC scheme is applied to text transmission, where the distribution of alphabets is nonuniform. For the transmission of the 128 ASCII characters using the proposed scheme through UART ports, a dimming range 23.1%-76.9% is guaranteed and the transmission rate is maintained. The proposed scheme can provide existing LED lighting systems with an efficient dimmable VLC feature.

Keywords

computer interfaces; data communication equipment; light emitting diodes; optical receivers; optical transmitters; ASCII character transmission; LED dimming control; LED lighting systems; UART ports; VLC scheme; alphabet distribution; dimmable VLC feature; dimmable visible light communication; dual-codeword allocation scheme; symbol distribution; text transmission; universal asynchronous receiver-transmitter; Dimming; LED; OOK; UART; VLC;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2013.2264281

Filename

6517502