Burst-Mode Resonant LLC Converter for an LED Luminaire With Integrated Visible Light Communication for Smart Buildings

Abstract

This study presents a digitally controlled LLC resonant dc-dc converter targeted to white LED luminaires in smart buildings. The module uses the LED array both for ambient lighting and for transmitting sensor data. Visible light communication is implemented with minimal incremental cost, by operating the LLC converter in burst mode, without causing any visible disturbance. The converter operates with a regulated average LED current, while the burst pulse timing is controlled to minimize the current disturbance and reduce the output capacitance. Variable pulse position modulation is used to modulate the data, while supporting a range of dimming settings. A digital demodulation scheme that supports variable frequency transmission is demonstrated. The 80 W, 340-400 to 23 V converter prototype has an efficiency of 95.1%. The bit error rate of the complete system is fully characterized versus distance and angle.

Reproducing Single-Carrier Digital Modulation Schemes for VLC by Controlling the First Switching Harmonic of the DC–DC Power Converter Output Voltage Ripple

“…Fig. 3 shows the two most extended approaches for performing that method: using a MOSFET in series [36]- [37] or in parallel [38]- [40] with the HB-LED string. In these methods, the data rate is determined by the pulse waveform frequency, which is strongly limited by the HB-LED bandwidth.…”

“…This modulation family has already been proposed for VLC and their benefits have been demonstrated in [23] and [50]- [57]. Since the method presented in this work is fully based on the use of DC-DC power converters (i.e., power efficient approach), the target is to improve the results achieved in [37] and [39] (i.e., power efficient approach reproducing an inefficient modulation scheme).…”

“…It is important to note that PSK, ASK and QAM have a higher spectral efficiency than the Variable Pulse Position Modulation (VPPM) scheme reproduced in [37] and [39]. Therefore, these single-carrier digital modulation schemes provide higher data rates using the same bandwidth, being QAM the one that achieves the highest spectral efficiency.…”

Power-Efficient VLC Transmitter Based on Pulse-Width Modulated DC–DC Converters and the Split of the Power

“…In this sense, two main approaches can be found in the literature. The first one consists in generating light pulses for transmitting the information [11]- [15] [see Fig. 1(a)].…”

Performance evaluation of a VLC transmitter based on the split of the power

“…Two main approaches can be found in the literature. The first one consists in generating light pulses for transmitting the information [9]- [10] [see Fig. 1(a)].…”