On the Role of Power Electronics in Visible Light Communication

The continuous demand of increasing data rates provided by wireless communication systems is contributing to saturating the RF spectrum. Visible Light Communication (VLC) systems aim to alleviate this congestion by using the visible light spectrum. These systems have been proposed to make use of High-Brightness LEDs (HB-LEDs) not only for lighting, but also for transmitting information by rapidly changing the intensity of the emitted light. A critical issue is that VLC requires a fast HB-LED driver in order to reproduce the target light intensity waveforms, which can include components of several MHz. Consequently, the HB-LED drivers proposed to date are based on the use of an RF Power Amplifier (RFPA). These devices provide the required speed, but suffer from very high power losses. To overcome this drawback, different solutions based on the use of fast-response DC/DC converters are presented in this paper. Several DC/DC converters, either to be used instead of an RFPA or to help an RFPA to achieve high efficiency, are thus analysed. The proposed HB-LED drivers enable the implementation of VLC transmitters without sacrificing one of the most important advantages of HB-LED lighting, namely its high power efficienc