Ricerc@Sapienza

The application of visible light communication (VLC) systems is to transmit data while maintaining efficient and good quality illumination service. In order to meet standard lighting requirements when multi-colored modulation techniques are used, such as color shift keying (CSK), the color fluctuation becomes a relevant issue. This paper presents a multi- primary (multi-color) modulation technique which provides reliable data transmission while keeping a strong constraint on the light color illuminated by every symbol of the modulation alphabet.

In the emerging framework of visible light communications, the limitation of modulation bandwidth of light emitting diodes (LEDs) transmitters is counterbalanced by the use of red-green-blue (RGB) LEDs since they exhibit higher modulation bandwidth. Using RGB LEDs allows to exploit the spatial multiplexing aspects, that is obtaining parallel channels for transmission. In this context, we used at the receiver RGB-tuned photodiodes (PDs). Hence each PD can, in principle, detect only the information its tuning is matched to.

The ever-increasing number of vehicles on a global level signifies the need for communications between vehicles and the surrounding environment. Visible light communications (VLC) is a viable complementary technology to congested radio-frequency-based wireless systems.

Visible Light Communication (VLC) is based on the dual use of the illumination infrastructure for wireless data communication. The major interest on this communication technology lies on its specific features to be a secure, cost-effective wireless technology. Recently, this technology has gained an important role as potential candidate for complementing traditional RF communication systems. Anyway a major issue for the VLC development is a deep comprehension of the noise and its impact on the received signal at the receiver.