Coordinated Interference Management for Visible Light Communication Systems

In this paper, we consider the performance of a visible light communication (VLC) network with coordinated interference management. The VLC transmitters are allowed to coordinate their transmissions using one of two transmission schemes so as to maximize a network utility function. In the first technique, namely, orthogonal transmission, the utility function is maximized by optimally partitioning all resources. In the second technique, namely, power control, the transmitters are allowed to share the full spectrum while being allowed to control their power so as to maximize network performance. In particular, for each transmission technique, we optimize a general network utility function under the constraint of a desired illumination power for each VLC transmitter, taking into consideration the optical signal clipping effect due to the physical limitations of the VLC transmitters. For the power control transmission scheme, we develop a computationally efficient method for finding the optimal power values by deriving a computationally efficient way to obtain the achievable spectral efficiency region. Considering the summation and the proportional fairness utility functions, our simulation results show that the optimal transmission scheme depends on the location of the VLC users and the desired illumination power. Also, we show the superiority of the performance of the power control scheme over the orthogonal transmission scheme for low interference regions.