Joint Mechanical and Electrical Adjustment of IRS-aided LEO Satellite MIMO Communications

In this correspondence, we propose a joint mechanical and electrical adjustment of the intelligent reflecting surface (IRS) to improve the performance of low Earth orbit (LEO) satellite multiple-input multiple-output (MIMO) communications. In particular, we construct a three-dimensional (3D) MIMO channel model for the mechanically-tilted IRS in general deployment, and consider two types of scenarios with and without a direct path of LEO-ground user link due to the orbital flight. With the aim of maximizing the end-to-end performance, we jointly optimize tilting angle and phase shift of IRS along with the transceiver beamforming, whose performance superiority is verified via simulations with a real orbit data generated according to the Orbcomm LEO satellite specifications.