LED based lighting and communications: An emerging technology for a greener more sustainable future

The paper discusses on the effect that the growth in our energy consumption as a species is having upon the planet, and how the global lighting and telecommunications industries are major contributors. We demonstrate that through the adoption of LED based lighting combined with visible light communications, substantial economical and power savings by orders of magnitude can be made over existing technologies, contributing towards a greener more sustainable future. The future of LED technology is also discussed with a focus on organic technology, promising increased savings

A Survey on Recent Advances in Organic Visible Light Communications

Visible light communication (VLC) employs light emitting diodes (LEDs) to provide illumination and data communications simultaneously. Organic LEDs (OLEDs) employing small molecules and long-chain polymers PLEDs, have been gaining attention within the VLC research community due to their inherent advantages such as flexible substrates and low-cost manufacturing. However, the carrier mobility of organic semiconductors is much slower than the devices composed of metal alloys, such as gallium nitride, thus leading to a restriction in the OLED modulation bandwidth. The manufacturing processes, materials and the photoactive size of the devices can affect the raw bandwidth of OLEDs. To increase the transmission speeds, novel approaches have been proposed including equalization techniques, signalling schemes and the optimum driver circuits. The paper provides a survey on the evolution of OLED-based VLC systems, and the respective challenges and recent progresses

Visible Light Communications for Indoor Applications

The field of visible light communications (VLC) has undergone a rapid development in recent years. The increased utilization of light emitting diodes (LEDs) has opened new possibilities for especially indoor services such as broadband internet connection and po- sitioning. Thus, a research within VLC is the main focus of the thesis and is divided into two main parts. At rst, the multiband carrier-less amplitude and phase (m-CAP) mod- ulation, introducing a newly adopted format for spectrally e cient VLC links, is under investigation using both theoretical and experimental approaches. The recommendations for m-CAP transmitter site design are proposed. Next, the channel modeling of indoor VLC is investigated with emphasis on the dynamically changing environments caused by moving people and non-line of sight (NLOS) propagation and new statistical models are derived.Katedra elektromagnetického pol

Characterization of the organic LED based visible light communications

This paper presents experimental results on a visible light communications system utilizing organic light-emitting diodes (OLEDs) and 16-quadrature amplitude modulation. The modulation bandwidth of the OLED device is limited to 310 kHz and the signal is generated on carrier frequencies fc = {100, 200, 300} kHz for use across different regions of the OLED frequency response. We demonstrate how setting a specific carrier frequency can affect the system performance. The supported bit rates are 220, 640 and 260 kb/s for fc = 100, 200 and 300 kHz, respectively. The angular dependence of the system performance is also analysed