Impact of crosstalk on indoor WDM optical wireless communication systems

In this paper, we investigate the impact of optical crosstalk on our recently proposed indoor gigabit optical wireless (OW) communication system incorporating wavelength division multiplexing (WDM). A theoretical model that allows this impact to be assessed has been proposed. The analytical results are validated via experiments. We show that the power penalty due to crosstalk in our proposed indoor WDM OW system is lower compared to that in the conventional optical fiber communication systems. In addition, it is found that the power penalty due to crosstalk is lower for the higher speed system since the receiver preamplifier-induced noise dominates the noise process. Finally, the maximum error-free beam footprint for different levels of optical crosstalk has been investigated. The results show that, for the 10- and 12.5-Gb/s systems, the maximum error-free beam footprint is only reduced by ∼5 cm, even with comparatively strong crosstalk.