Current density adaptation for an optical wireless communication system

Abstract

This invention relates to an optical wireless communication system that adapts current density of a light source depending on the link demands. To control current density independently of total current, a light emitting diode (LED) is used that allows adaption of the surface area of the active part of the junction or quantum well through which the current is sent. In an example, the total current is a constant and determined by the allowed power consumption, but nonetheless multiple LEDs are mounted. The current can be adaptively divided among the LEDs, where for short range communication a single LED is used (at high current, high bandwidth, lower efficiency), while for longer-range communication, more LEDs, thus lower current density (thus higher efficiency) are used, or where a selection is done among a fast operating mode with two active LEDs for short distance, a medium operation mode with one active LED with higher current density, and a slow operating mode with one active LED with lower current density for long distance.

Dependencies are inferred from the claim text.