Abstract
This paper presents an improved white light-emitting-diode (LED) wireless transmitter for the Joint Illumination and Communication (JIC) System, which consists of two parts: the driver circuit and the pre-emphasis circuit. The main purpose of the driver circuit part is to solve the problem of dissipated power when sweeping the remaining carriers during the signal modulation of the high-efficiency, high-power and high-speed white LED driver. A push-pull structure driver with a current conduction angle less than 180 degrees is proposed, which is analogous to a Class C power amplification driver, thus avoiding the simultaneous existence of voltage and current on the driver circuit when the remaining carriers are swept out, and improves the efficiency of the LED driver. On this basis, the pre-emphasis circuit part adopts the phase shift technology to improve the data transmission rate, and the system efficiency has also been improved. Then, an improved class C push-pull structure white LED driver with phase shift pre-emphasis technology is formed. This novel driver and pre-emphasis technology achieve a system efficiency of 95.73% with a 10 W LED. The test results show that the system communication -3 dB bandwidth expanded from the original 8.3 MHz to 13.67 MHz, and the best-obtained transceiver baud rate is 25 Mbps at a distance of 1.3 m with BER of 1.63 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> . The test result verifies that the LED driver proposed in this paper is currently the highest figure of merit (FoM) for high power JIC systems.
Highlights
Nowadays, high-power white light-emitting-diodes (LED) have gradually replaced traditional incandescent and fluorescent lamps as the main light source for lighting, because of their advantages such as energy saving, high efficiency, long life, and low cost
The joint illumination and visible light communication (JIC), whose energy consumption for data transmission comes from the lighting, can save the costs of infrastructure installment, and the transmission energy can be used for lighting in return, reducing more power consumption [2]
The development of visible light communication (VLC) technology in indoor illumination has many advantages, such as strong confidentiality, no need to apply for radio frequency (RF) spectrum, and anti-RF interference [10]–[11]
Summary
High-power white light-emitting-diodes (LED) have gradually replaced traditional incandescent and fluorescent lamps as the main light source for lighting, because of their advantages such as energy saving, high efficiency, long life, and low cost. By changing the static operating point voltage VQ of the common source amplifier composed of two LDMOS (M4, M5) to be less than the Vth of the GaN FET, only the part of the input signal in the driver circuit that is larger than the Vth can turn on the GaN FET In this way, the signal conduction angle of the driver circuit can be adjusted to be less than 180 degrees, and when the signal makes the LED in a bright or dim state, the conduction angle of the GaN FET is less than half a period as shown in Figure 3 (b).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
