In this paper we propose a simulation method using numerical integration, and develop a closed-form link loss
model for physical layer channel characterization for non-line of sight (NLOS) ultraviolet (UV) communication
systems. The impulse response of the channel is calculated by assuming both uniform and Gaussian profiles for
transmitted beams and different geometries. The results are compared with previously published results. The
accuracy of the integration approach is compared to the Monte Carlo simulation. Then the path loss using the
simulation method and the suggested closed-form expression are presented for different link geometries. The
accuracies are evaluated and compared to the results obtained using other methods.