Performance Analysis of Aerial Intelligent Reflecting Surface-Aided Networks

Aerial intelligent reflecting surfaces (AIRSs) under a certain height (h) will provide a higher probability of line-of-sight (LoS) links. However, this will also introduce the three-dimensional (3D) dynamic cascaded channels with Rician fading and the severe interference from other base stations (BSs) randomly scattered by the AIRSs leading to the performance fluctuation, which are the impacts that need to be analyzed. This paper proposes a 3D network model for ground users assisted by AIRSs considering the interference introduced by other BSs and that scattered by AIRSs to obtain the theoretical formula of coverage probability (CP) to analyze the system performance of such a network where the impacts of dynamic cascaded channels varying with h are also considered. Specifically, the deployment of AIRSs is given by a 2D homogeneous Poisson point process (HPPP) with h and thus the cascaded channel model is given to capture the contributions of LoS/NLoS links with height-sensitive Rician factor to re-derive the Gamma approximation of signal power distribution considering the O(N-2)-gain brought by AIRS beamforming. In addition, the severe interference introduced by AIRSs through more LoS links is considered and then derive the formula of CP considering different deployment parameters. The numerical results show that the CPs of the users are significantly increased by about 62% and 77% by the aid of AIRSs compared with the IRS-aided network when h = 25 m under different conditions with a larger working range while AIRSs are deployed in a more centralized manner.