Measurement of the Modulation Bandwidth of High-Power Chip-on-Board LEDs for VLC systems

During the last decade, the LED technology has developed lamps up to 90% more efficient in terms of energy and brightness in comparison with the use of halogen technology. Indeed, the manufacture of halogen lamps are currently banned in the European Union and it is forecasted that most of the halogen lamps will leave no trace before 2024. In this context, visible light communications (VLC) have been proposed to exploit the LED technology for providing both illumination and data transmission. VLC is particularly attractive for industrial environments where RF transmission is not efficient such as tunnel construction, mining, or oil&gas plants. However, the use of commercial LEDs is required to scale the implementation of the VLC technology so that the current deployment of LEDs can be exploited for providing connectivity. In this work, the use of high-power chip-on-board (CoB) LEDs typically deployed in industrial environments is analyzed. To do that, a VLC communication link is implemented using a CoB high-power LED, and a novel measurement methodology is applied to determine the parameters that hamper the achievement of high-data rates. The obtained results show that CoB LEDs are useful for medium-data rates applications while they are not suitable for high-data rate solutions.