Presentation: Enhancing indoor optical wireless communication system performance by sectorization by J. -P. M. G. Linnartz, P. Van Voorthuisen and Ch. Hoelen at SPIE OPTO, Light-Emitting Devices, Materials, and Applications XXVI

Abstract: The shortage on radio spectrum forced to a high sophistication in spectrum efficiency. Optical wireless communication (OWC), rather than RF communication, may be a game changer, as the available optical spectrum is sheer unlimited. In addition, light can more easily be directed to the desired user (only). Narrowing the emitted light beams allows denser reuse, even within one room, and enables an increase in throughput. The authors report their experience from creating indoor OWC systems and verify these insights against throughput models. The trade-off between high throughput in only a narrow beam versus offering a wide coverage area is discussed. LEDs and free-form optics allow simple ways to direct a beam, which is more attractive than a phased-array as used in RF. The suitability of a Lambertian radiation patterns is challenged and compared to an optical system that is designed to provide constant irradiance. An example of a sectorized system comprising four segments with free-form optics is presented and its performance and characteristics are discussed, for a Lambertian and a directional detector.