Model and Methodology to Characterize Phosphor-Based White LED Visible Light Communication Links

LED lighting has become the standard solution for illumination purposes thanks to its energy efficiency. Nowadays, there is growing interest in the use of LEDs for data transmission to develop future-generation communication systems. The low cost and widespread deployment of phosphor-based white LEDs make them the best candidate for visible light communications (VLC), although they have a limited modulation bandwidth. This paper presents a simulation model of a VLC link based on phosphor-based white LEDs and a method to characterize the VLC setup used to perform the data transmission experiments. Specifically, the simulation model incorporates the frequency response of the LED, the noise levels coming from the lighting source and the acquisition electronics, and the attenuation due to both the propagation channel and the angular misalignment between the lighting source and the photoreceiver. In order to validate the suitability of the model for VLC, carrierless amplitude phase (CAP) and orthogonal frequency division multiplexing (OFDM) modulation signals were employed for data transmission, and simulations with the proposed model and measurements over the equivalent scenario show high agreement.