As anyone who has used WiFi in urban environments knows, there is interference between multiple competing users and loss of throughput. Wireless home networks are not just for casual web browsing, but are also being used to stream high-quality video to tablets and other portable devices. Interference between access points degrades the user experience for these applications. One method being proposed to address the increased demand for high-capacity local-area wireless networking is Free-space-optical communication (FSOC). In parallel, solid-state lighting (SSL) devices with multiple light emitting diodes (LEDs) are being deployed and commercialized due to their superior durability and energy efficency. Though stemming from the same core optoelectronics technology, SSL and FSOC have inherent tradeoffs: the illuminated area is larger when the divergence angle of the optoelectronic transmitter is high, whereas the transmission range is longer when it is small. This project envisions multi-element "illuminication" modules that perform joint and adaptive optimization of two conflicting goals: illumination and communication. Such modules and protocols are potentially deployable in many settings such as residential and commercial buildings, airplanes, and other RF-limited environments.
This projects is developing a framework to design, optimize and test illumination-communication technologies considering needs and requirements for both functionalities. To attain mobile illuminication with high spatial reuse and throughput, and uniformly high illuminance; the project designs (i) multi-element illuminication modules which uses spherical structures for spatial reuse and uniform illumination, (ii) adaptive intensity control for energy saving and chromacity control over red-green-blue LEDs, (iii) transceivers with varying field-of-view and divergence angle, (iv) automatic realignment protocols using electronic steering and focusing for mobility, (v) cognitive algorithms for transceiver selection, and (vi) optical wireless localization with high accuracy.
