For the past ten months, pureVLC’s partner, the University of Edinburgh (UoE), has been actively engaged in a research collaboration with some of the top universities in the UK, in particular: Strathclyde, St. Andrews, Oxford, and Cambridge. The project called “Ultra-parallel visible light communications (UP-VLC)” is funded by the UK’s Engineering and Physical Sciences Research Council (EPSRC). Its primary goal is the demonstration of a real-time duplex free space optical wireless communication link with transmission speeds in excess of 1 Gbps over a distance of at least 1 m.
At the heart of this research initiative lie the newly-introduced micro-sized gallium nitride light emitting diodes (LEDs) pioneered by Strathclyde University. As part of the UP-VLC project, a joint research experiment was recently conducted between University of Edinburgh and University of Oxford with the aim of demonstrating high-speed communication with the micro-LED devices under investigation. As a result, achievable speeds of up to 1.67 Gbps have already been reported. Recent improvements in experimental setup and methodology have revealed that communication even on the order of 3 Gbps is achievable from a single LED (as shown in the picture). This result has been already independently achieved in both the research labs in Edinburgh and in Oxford. It is expected that even further improvement can be accomplished.
The 3dB bandwidth of the 60-micron gallium nitride devices under investigation is in the order of 30 MHz. However, with the usage of clever orthogonal frequency division modulation (OFDM) based modulation algorithms, a system bandwidth of over 600 MHz has been realised. The research group at University of Edinburgh specialises in advanced OFDM-based modulation techniques, which have not only enabled the reported results, but also provide the possibility to even further increase communication speeds and at the same time decrease the power requirements of the system. Despite the heavy research which has been conducted in this field over the past five years, researchers in Edinburgh believe that the novel, recently-conceived ideas will allow them to demonstrate further impressive results.