Indoor Positioning
The Technology
Positioning,also known as localization, is the process of determining the position of an object or person. Accurate positioning is critical for numerous applications.
The familiar Global Positioning System (GPS), originally a US military system,is now in everyday use around the world, often in new and unexpected ways. However, despite decades of research into indoor positioning using radio frequency signals, there is still no system which is cheap, accurate, and widely available.. The fundamental problem in radio based systems is that multipath transmission distorts the transmitted signals.
The widespread introduction of white light emitting diodes (LEDs) for illumination provides an unprecedented opportunity to fill this gap. Look up in almost any building and you will be able to see multiple light fittings, demonstrating that at most indoor locations, a receiver could be designed to receive signals from multiple light sources. LEDs can be modulated at much higher frequencies than conventional lighting, so the signals required for positioning can readily be transmitted at frequencies that do not cause visible flicker.
Visible light positioning VLP) using LEDs is a new and exciting research area with many multidisciplinary research questions and huge practical potential. Our recent papers on VLP cover topics as diverse as the fundamental Cramer-Rao bounds on positioning using time-of-arrival, to designing novel lens configurations to provide accurate angle-of-arrival information.
