On the Coverage Performance of Reconfigurable Holographic Surfaces-aided LEO Satellite Communication Networks

The low earth orbit (LEO) satellite networks are looking forward to a new large scale antenna technology for high-speed data services and global massive connectivity. Traditional phased arrays have their limitations in realizing large scale antenna arrays for their complexity and high power consumption. Reconfigurable holographic surface (RHS) has recently shown its potential in implementing large scale antenna arrays due to its capability of accurate multi-beam steering with low power consumption. In this paper, we consider an RHS-aided LEO satellite communication network, where each satellite equipped with an RHS serves multiple user terminals (UTs). We first derive the closed-form expression of downlink coverage probability of the RHS-aided LEO satellite communication network. A tight and tractable approximation for the coverage probability is then derived to facilitate the following analysis. After that, the influence of the RHS element number, satellite number and UT number on the coverage probability is analyzed. Simulation results validate the theoretical derivations and show that the coverage probability increases with the negative exponent of the reciprocal of the number of RHS elements and there exists an optimal satellite number in the visible spherical cap that maximizes the coverage probability.