Spherical Large Intelligent Surfaces

As an emerging technology and evolution that goes beyond massive multi-input multi-output (MIMO), large intelligent surface (LIS) has gained much interest recently. LIS acts as an electromagnetic surface and can transmit, redirect, and receive radiating signals across its entire contiguous surface. It allows for unprecedented energy-focusing, data-transmission and terminal-positioning, and can fulfill the most grand visions for future communication systems. Earlier proposed LISs are in two-dimensional (2D), i.e., planar shapes. In this paper, we extend LIS to be three-dimensional (3D) and deployed as spherical surfaces. Compared to 2D shapes, spherical LISs have advantages of wide coverage, simple positioning techniques, and flexible deployments as reflectors.