Impact of Passband Shift in Optical Wireless Communication Systems based on Wavelength Division

In this paper we investigate the impact of the passband shift (PS) phenomenon on optical wireless communication (OWC) systems based on wavelength division (WD). We first introduce the associated challenges, then we discuss the mathematical framework needed to evaluate the performance of systems based on WD when the impact of the PS phenomenon is taken into account. We introduce the concept of spectral overlap (SO) and discuss its role in the design of WD solutions. Results show that this design phase has to take the SO into account, and that its careful balance with the channel gain is essential when multiple colours are used for parallel communication in OWC.