Distortion correction in radio on visible light (RoVL) communication system for mobile applications

The demand for sophistication furnished by communication systems has led to the inception of new ways to compliment & supplement conventional communication technologies. One system that has recently captivated global attention is visible light technology utilizing white LED for synchronous illumination & communication. Although, radio setup progresses to be an integral part of mobile telecommunications in bestowing easy and instant connectivity to majority of human population. It comes with some paucity in terms of quality of service (QOS) when administering coverage to RF restricted or poor signal connectivity regions, dispensing the exploration of auxiliary means for indoor radio transmission. A subject worth considering when contemplating radio information through visible light is the slight degree of non linearity exhibited by the LED. The following paper delineates the fundamental parameters of LED nonlinearity, forming the integral foundation for experimental testing & measurements. An electronic predistorter using diode model is proposed and its performance tested using the single and two tone frequency analysis. It is evidently marked that with the predistorter, an intermodulation correction of up to 40 dBV is attained, adhering to the compelling prerequisites set by the global mobile standards to sustain indoor mobile signal transmission.