Distance and power based experimental verification of channel model in visible light communication

Abstract

In this work, a channel model for line-of-sight (LOS) in visible light communication is elaborated. In the proposed channel model, there is no optical component, such as filter or lens, between the transmitting LED and the receiving photodiode. Later, a suitable setup is built for emulation of the mentioned channel model. In the setup, the LED and the photodiode are located in a line-of-sight orientation. The change of the optical power on the photodiode is measured by varying the distance between the LED and photodiode. The measurement result is compared with the channel model. The channel model is in good agreement with the measurement results. Following that, the signal-to-noise ratio (SNR) at the output of the receiver, as a function of the distance, is measured. Measurement results indicate that the SNR value remains below 15 dB after exceeding a distance of 20 cm for the specific LED-Photodiode pair used in the experiment. The optical signal on photodiode drops to the noise level when the distance exceeds 50 cm.