An LED Communication Model Based on Carrier Recombination in the Quantum Well

Optical Wireless Communication (OWC) is gaining popularity as it potentially offers interference–free communication in dense environments. By using LEDs, cells of very small size can be created with sharp boundaries thus bandwidth can be reused very densely. Building an effective communication systems starts from understanding the channel. In scientific literature, various models for the LED response are in use. This overview paper starts from the non-linear recombination of electrons and holes in the LED semiconductor junction, which then appears to lead to a very tractable and simple signal processing model. In fact, the LED channel substantially differs from a radio channel. The paper summarizes recent progress in developing an LED channel model, based on the physics of photon generation in the active region. The LED Quantum Well (QW) creates a first–order low–pass effect and the hole-electron re-combinations are inherently non-linear. Thereby the LED exhibits dynamic distortion, that is, non-linearities that are are intertwined with memory effects. The model can be used to reduce power consumption and to increase throughput of LED OWC systems.