Power Allocation of Non-Orthogonal Multiple Access with Variable on-off Keying Dimming Control in Visible Light Communication Networks

Visible light communication (VLC) transmits the wireless data through optical scintillation. However, the joint problem of both illumination and communication remains the tradeoff challenge. For both illumination and communication, this paper adopts dimming control to flexibly adjust the brightness for human eyes, and introduces non-orthogonal multiple access (NOMA) to improve the system throughput. First, we establish a model combining signal power allocation with dimming control. Second, for the enhancement of spectral efficiency, we introduce gain ratio power allocation (GRPA) of NOMA and variable on-off keying dimming control. Third, in the indoor user scenario, we analyse the relationship of luminescent angles, user data rate, and luminous intensity. Finally, experimental results indicate that the proposed GRPA scheme achieves the better performance than the previous strategy in user data rate for the same dimming factor. Furthermore, the optimal indoor VLC cell deployment of semi-angles and dimming factors is discussed.