  Reconfigurable Intelligent Surfaces (RIS) or Intelligent Reflecting Surfaces
(IRS) are metasurfaces that can be deployed in various places in wireless
environments to make these environments controllable and reconfigurable. In
this paper, we investigate the problem of using 3D beamforming in RIS-empowered
wireless networks and propose a new scheme that provides more degrees of
freedom in designing and deploying the RIS-based networks. In the proposed
scheme, a base station (BS) equipped with a full dimensional array of antennas
optimizes its radiation pattern in the three-dimensional space to maximize the
received signal to noise ratio at a target user. We also study the effect of
angle of incidence of the received signal by the RIS on its reflecting
properties and find a relation between this angle and the BS antenna array's
tilt and elevation angles. The user receives the signal from a reflected path
from the RIS as well as from a direct path from the BS which both depend on the
BS antenna array's tilt and elevation angles. These angles and also the RIS
element's phase shifts are jointly numerically optimized. Our simulation
results show that using RIS-assisted 3D beamforming with optimized phase shifts
and radiation angles can considerably improve the performance of wireless
networks.
