One-Bit Sigma-Delta Modulator for Nonlinear Visible Light Communication Systems

Author

Hua Qian ; Juan Chen ; Saijie Yao ; Zhenhua Yu Zhang ; Hua Zhang ; Wei Xu

Author_Institution

Key Lab. of Wireless Sensor Network & Commun., Shanghai Res. Center for Wireless Commun., Shanghai, China

Volume

27

Issue

4

fYear

2015

fDate

Feb.15, 15 2015

Firstpage

419

Lastpage

422

Abstract

In a visible light communication (VLC) system, the modulation bandwidth of light emitting diode (LED) is limited with current technology. In addition, the nonlinearity inherited in the LED prevents the application of spectral efficient modulation schemes with high peak-to-average power ratio. These characteristics limit the overall throughput of the VLC system. In this letter, a one-bit sigma-delta modulator (SDM) is introduced to the transmit signal. Such modification is compatible with the current LED lighting systems and LED drivers as the output of the one-bit SDM is equivalent to ON-OFF keying signal, thus is immune to system nonlinearities. In addition, the output of the one-bit SDM enjoys high spectral efficiency as the original input signal does. The out-of-band quantization noise can be taken care of at the receiver with analog filtering and digital signal processing. Simulation and experiment results validate that the SDM can significantly improve the VLC system performance.

Keywords

LED lamps; amplitude shift keying; filtering theory; optical communication equipment; optical modulation; sigma-delta modulation; LED drivers; LED lighting systems; VLC system; analog filtering; digital signal processing; light emitting diode; modulation bandwidth; modulation schemes; nonlinear visible light communication systems; on-off keying signal; one-bit SDM; one-bit sigma-delta modulator; peak-to-average power ratio; quantization noise; spectral efficiency; Bandwidth; Bit error rate; Light emitting diodes; Modulation; Noise; Peak to average power ratio; Quantization (signal); Sigma-delta modulator; Visible light communications; nonlinearity; sigma-delta modulator;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2014.2376971

Filename

6975115