Coverage Analysis of Multiuser Visible Light Communication Networks

In this paper, a new mathematical framework for the coverage probability analysis of multiuser visible light communication (VLC) networks is presented. It takes into account the idle probability of access points (APs) that are not associated with any users and hence do not function as the source of interference. The idle probability of APs is evident especially in underloaded networks as well as general networks that operate with an AP sleep strategy to save energy and/or minimize the co-channel interference. Due to the absence of the "multipath fading" effect, the evaluation of the distribution function of the signal-to-interference-plus-noise ratio (SINR) is more challenging in VLC networks than in radio frequency-based cellular networks. By using the statistical-equivalent transformation of the SINR, analytical expressions for the coverage probability are derived and given in tractable forms. Comparing the derived results with extensive Monte Carlo simulations, we show that assuming a thinned homogeneous Poisson point process for modeling active APs is valid in general, and it gives close results to the exact ones when the density of users is no less than the density of APs in the network. Both analytical and simulation results show that, for typical receiver noise levels (similar to-117 dBm), approximating the SINR by the signal-to-interference ratio is sufficiently accurate for the coverage analysis in VLC networks.