Flicker Free Visible Light Communication Using Low Frame Rate Camera

Over the years, more and more conventional lighting systems tend to be replaced by LED lighting systems because of their advantages such as high energy efficiency, longer lifespan and lower heat generation. Because of the LEDs' capability of switching to different light intensities at fast rate, these lighting solutions could be used for both illumination and transferring data. This characteristic of the LEDs has led to the development of a new technology, known as Visible Light Communication (VLC). In this type of communication, the receiver is usually a photodetector. Lately, the tendency is to also use video cameras to receive the transmitted data. Solutions exist, but they use expensive cameras that can capture over 800 frames per second (fps). The communication proposed in the paper uses a LED as a transmitter and a camera with a common frame rate (120 fps) as the receiver. At those frame rates the challenge is to use a code that avoids flickering and does not need a synchronization between the transmitter and the receiver. A version for such code is also presented in the paper. The system was implemented and tested. The results confirm the functioning of the proposed low frame rate VLC communication system.