Illumination system for communicating data

#This application is the U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCT/EP2018/068610, filed on Jul. 10, 2018, which claims the benefit of European Patent Application No. 17182125.9, filed on Jul. 19, 2017. These applications are hereby incorporated by reference herein.

#The present disclosure relates to an illumination system for illuminating an environment and also enabling communication of data between the illumination system and a user device on a downlink and/or uplink. The downlink signal may be embedded in visible light or infrared light emitted by the luminaires of the system. The uplink may advantageously utilize a short-range, unlicensed medium such as infrared.

#Visible light communication (VLC) refers to techniques whereby information is communicated in the form of a signal embedded in the visible light emitted by a light source. VLC is sometimes also referred to as coded light. The signal is embedded by modulating a property of the visible light, typically the intensity, according to any of a variety of suitable modulation techniques. For instance this enables a sequence of data symbols to be modulated into the light emitted by a light source. Based on the modulations, the information in the coded light can be detected using any suitable light sensor. This can be either a dedicated photocell (point detector), or a camera comprising an array of photocells (pixels) and a lens for forming an image on the array. E.g. the sensor may be a dedicated photocell included in a dongle which plugs into a mobile user device such as a smartphone, tablet or laptop; or the sensor may be a general purpose camera integrated into the mobile user device. Either way this may enable an application running on the user device to receive data via the light.

#To assist understanding of the present disclosure and to show how embodiments may be put into effect, reference is made, by way of example only, to the accompanying drawings in which:

#FIG. 1 is a schematic block diagram of an illumination system that also enables duplex communications,

#FIG. 2 is a schematic plan view of a plurality of cells of the system,

#The following describes a system for creating a large area of optical wireless reception with several receivers connected to a common optical wireless communication system. The optical wireless communication system comprises: a transmitter part with a single modulator connected by multiple plastic optical fibers to different luminaires, and a receiver part which includes several feedback channels to a common demodulator. All these elements may be implemented for example in the same room. The aim is to manage the overlapping between nodes and also negate the need for handover between them.

#On the downlink the system comprises several emitters but they all send the same signal.

#On the uplink, the system comprises several emitting user devices sending different signals but not at the same time most cases (TDMA) except for polling. The user device may for example a user terminal such as a laptop or tablet having a dongle plugged in enabling the user device to communicate via optical wireless.