Comunicații optice în spectrul vizibil / Optical communications in the visible spectrum

Without noticing, we are surrounded by substantial data blocks that ensure the proper functioning of the equipment around us, from mobile phones, remote-controlled devices to wireless internet. However, it generates an overwhelming demand for radio frequencies so that data can be transmitted in the context in which the radio spectrum is a finite resource. This phenomenon has led to a rapid increase in the use of LEDs to develop new dual-purpose applications, namely, to provide illumination and allow data transfer. The topology of current applications uses video recording cameras to decode the data transmitted by LEDs, where the frame acquisition speed allows faster and more robust data transfer. Thus, video cameras with a high number of frames/s are exploited to improve the experience of using optical communication in the visible spectrum, but their cost makes them an impractical solution for large-scale use. In this context, this thesis presents a review of the literature in the field of wireless optical communications and contributes to increasing the performance of optical communication systems by optimizing them using communication codes appropriate to the particularities of the transmission channel. It also investigates the use of recording cameras with a low number of frames/s, the degradation of the received signal in the visible spectrum communication, the key elements of infrastructure-vehicle communication, and presents preliminary results of the use of visible spectrum communication for road signalling infrastructure communication, along with performance analysis of a varied set of low-cost video cameras, which can guarantee stable communication.