High-Speed Visible Light Communications Using Multiple-Resonant Equalization

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> White light-emitting diodes (LEDs) are becoming widespread in commercial lighting applications, and there are predictions that they will be in common use in domestic applications in the future. There is also growing interest in using these devices for both illumination and communications. One of the major challenges in visible light communications is the low modulation bandwidth (BW) available from devices, which is typically several megahertz. In this letter, we describe a link that uses 16 LEDs which are modulated using a resonant driving technique, creating an overall BW of 25 MHz. This is used to implement a 40-Mb/s nonreturn-to-zero <emphasis emphasistype="smcaps">on–off</emphasis> keying link which operates at low error rates, and also provides illumination at levels sufficient for a standard office environment. </para>