Two-Dimensional Intensity Distribution and Adaptive Power Allocation for Ultraviolet Ad-Hoc Network

We consider a directional antenna array in an ultraviolet (UV) scattering communication ad-hoc network. To efficiently characterize the link gain coverage of a single antenna, we propose an algorithm based on one-dimensional (1D) numerical integration and an off-line data library. We also investigate the two-dimensional (2D) scattering intensity distribution, which shows that the link gain profile can be well fitted by elliptic models. In addition, assuming that the node distribution of an ad-hoc network obeys Poisson point process (PPP), we investigate the network connectivity probability and the minimum power that the network remains connected under different antenna parameters, and compare the performance of directional antenna array with that of omnidirectional antenna array. Numerical results show that employing directional antenna arrays can effectively reduce the power required for network connectivity. Moreover, we consider a two-layer network using directional antenna array, and design adaptive node assignment and power allocation to increase the minimum rate. Numerical results show that the proposed algorithm can improve the minimum node rate by more than 10%. Moreover, similar performance gain can be observed even considering the overhead of a media-access control (MAC) layer protocol.