Line-of-sight probability for UAV communications in 3D grid urban streets

In this letter, the authors present a novel expression for the probability of line-of-sight (LoS) between a UAV and ground users situated on a gridded street within urban and dense urban environments. Firstly, this study conducts extensive ray-tracing simulations, encompassing over 50,000 receivers positioned along streets in Brooklyn and Manhattan, respectively. Moreover, the impact of street width on the probability of LoS is investigated, considering three different average widths. By fitting the LoS probability data corresponding to the UAV's elevation angle in two urban environments obtained by simulations, a unified expression representing the relationship between the LoS probability and the UAV's elevation angle is obtained. This obtained LoS probability expression is compared with three existing expressions. The findings presented in this letter can provide some valuable insights for analytical studies on channel modelling between UAVs and ground-based street users including vehicles. The authors present a novel expression for the probability of line-of-sight (LoS) between a UAV and ground users situated on a gridded street within urban and dense urban environments based on ray tracing simulations. The authors found that when the UAV elevation angle ranges from 27 degrees to 52 degrees, the narrower the street, the greater the LoS probability in urban environments. For dense urban environments, when the UAV elevation angle is less than or equal to 33 degrees, the wider the street, the greater the LoS probability, and when the UAV elevation angle is greater than or equal to 46 degrees, the narrower the street, the greater the LoS probability.image