Controle de potência para aumento da eficiência energética em sistemas de comunicações ópticas por luz visível

Abstract

Optical Wireless Communications (OWC) is a technology very emerging, with high interest in industry and academia. This high interest in this technology is due to this being a complementary or substitutive alternative proposal for the radio frequency (RF) systems. This motivation is closely linked to spectrum scarcity of frequencies used in RF communications. OWC systems can be classified as indoor and outdoor, and are used for your LED or laser transmission. In particular, LED based systems are known as Visible Light or Visible Communications Systems Light Communications (VLC), systems that have gained more relevance due to the wide diffusion of LEDs as sources of lighting. The energy savings resulting from the use of LEDs is probably one of the most important benefits that can be gained by using VLC systems. We can consider that one of the biggest consumptions of electric energy today is due to the use of lamps for ambient light and for that reason, the development of light more efficiently is all too important. Some advantages of VLC systems in comparison to its RF counterpart are: broad spectrum for use, easy implementation, low cost, high energy efficiency, safe for human health, do not interfere with RF systems and can be applied in the areas of information security. In this context, the need arises to ensure an increasing optical energy efficiency in VLC systems, which can be achieved through power control strategies used in data transmission. This work brings an analysis through equations that mathematically model the systems VLC of different scenarios in which a control is applied on the optical power transmitted so that the received power remains within pre-established limits. In addition to power control executed, an internal positioning system was also included using the technology VLC. This system aims to obtain the position of the receiver and, together with this information, direct the transmitted power to this point, in order to expend a power that satisfies the conditions imposed on the power control.