Taking Advantage of the Sum of the Light in Outphasing Technique for Visible Light Communication Transmitter

Abstract

Visible Light Communication (VLC) takes advantage of the widespread use of the LEDs, and by modifying the driver stage, the LEDs are capable of lighting and transmitting information. One of the main drawbacks is the low power efficiency due to the modification of the LED driver stage in order to add the communication capability. Most of the research work related to VLC is towards the communication task, whereas there is a limited work about the improvement on the power efficiency. This paper proposes a high efficiency LED driver for VLC working as a transmitter based on the outphasing technique. This technique is used also in RF communications and increases the efficiency of the amplifiers. The proposed transmitter is made up of two switching-mode power amplifiers that reproduce the signals required for the outphasing technique and a DC/DC converter that biases the LEDs. The proposal exploits the light and, instead of being added electrically, the signals are added in their light form, which leads to a reduction in the complexity of the design. As experimental results, a transmitter was built of two Class E amplifiers reproducing a 16-QAM modulation, achieving a signal-generation efficiency of 78% and an overall efficiency of 92%.

Investigation of temperature variations on a Class-E inverter and proposing a compensation circuit to prevent harmful effects on biomedical implants

“…The Class-E inverter has been welcomed due to its high efficiency, circuit simplicity, and small size and therefore it has been the main element of practical circuits such as biomedical implants 16,17 , inverters [18][19][20] , WPT systems [21][22][23][24][25][26] , oscillators 23,28 , and light communication transmitter 29 . Due to these broad applications, a variety of techniques have also been used to design and optimize class E inverters for different WPT applications.…”

A complexity efficient PAPR reduction scheme for FBMC-based VLC systems

“…Moreover, VLC is more immune to interference, which *Corresponding author at: mohammed.adel@hti.edu.eg makes it widely used in indoor environments such as hospitals, aircrafts, etc. [9,10]. Light emitting diode (LED) technologies, have become more prominent and accessible, providing new contexts for VLC technology [11].…”

On the Use of Class D Switching-Mode Power Amplifiers in Visible Light Communication Transmitters

“…Therefore, the LPA of the VLC driver shown in Figure 1 could be replaced by a SMPA in order to alleviate the power efficiency problem. In this sense, previous works explored the use of Class E SMPAs [14], [15]. Unfortunately, that SMPA class is not able to modulate the amplitude of the communication carrier and, consequently, that approach only allows us to reproduce phase-modulated schemes.…”

“…Furthermore, it does not solve the limitation related to the reproduction of amplitude-modulated schemes. Alternatively, two VLC drivers based on the use of Class E SMPAs can be combined to reproduce amplitude-modulated schemes by implementing the outphasing technique [15]. Unfortunately, that approach leads to high complexity in terms of both hardware and control, which are critical parameters to be consider for designing HB-LED bulbs [16].…”