On Adaptive Network Deployment for Visible Light Communications

This work studies adaptive network deployment for visible light communications (VLC), which exploit light wave as signal bearers. In most of the current literature, the VLC user is served by a single access point (AP), called serial transmission. To enhance network flexibility, parallel transmission (PT) was developed for VLC, enabling the user to be served by multiple APs simultaneously. Specifically, each AP consists of different coloured light-emitting diodes (LEDs) and modulates only one of them to mitigate inter-cell interference. The receiver, equipped with wavelength division concentrators, can distinguish signals carried by different wavelengths. To further improve network flexibility, adaptive network deployment is proposed in this paper, by allowing the APs to modulate a dynamic number of LEDs. The adaptive scheme is comprised of three modes of network deployment, and the mode selection is formulated as an optimisation problem to maximise network capacity with proportional fairness. Results show that compared with the original PT method, the new scheme can significantly improve network throughput, especially with an increase of up to 40% for room corner users.