@INPROCEEDINGS{Papa2108:Energy,
AUTHOR="Maria Diamanti and Maria Tsampazi and Eirini Eleni Tsiropoulou and Symeon
Papavassiliou",
TITLE="Energy Efficient {Multi-User} Communications Aided by Reconfigurable
Intelligent Surfaces and {UAVs}",
BOOKTITLE="7th International Workshop on Sensors and Smart Cities (SSC 2021)
co-located with SMARTCOMP 2021 (SSC 2021)",
ADDRESS="Irvine, USA",
DAYS=23,
MONTH=aug,
YEAR=2021,
KEYWORDS="Unmanned Aerial Vehicles; Reconfigurable Intelligent Surfaces; Power
Control; Game Theory.",
ABSTRACT="To support the provisioning of modern services in a smart city environment,
future communication networks need to be intelligently designed with
respect to the city infrastructure and energy efficient utilization of
resources. Unmanned Aerial Vehicles (UAVs) are already being utilized as
part of a smart city wireless network infrastructure to provide on-demand
connectivity and eliminate the network's coverage holes, especially when
communication conditions are unfavorable. Complementary to this, the
adoption of Reconfigurable Intelligent Surfaces (RIS) technology, allows
for the creation of a more controllable smart wireless communications
environment. In this article, a multi-user Non-Orthogonal Multiple Access
(NOMA) communications system aided by a RIS and a UAV is studied. Based on
a single-leader multiple-followers Stackelberg Game, we aim to jointly
optimize the overall received signal strength at the UAV and maximize the
users' achieved energy efficiency. The UAV - acting as a leader -
intelligently steers the RIS-reflected signals in order enhance the
corresponding received signal quality, by determining the RIS elements'
optimal phase shift angles. This in turn is exploited by the users (i.e.
followers) which through the formulation of a non-cooperative game, where
each user aims at maximizing its achieved energy efficiency, they determine
their optimal uplink transmission power. The proposed optimization
framework is evaluated via modeling and simulation, demonstrating the
significant power savings and the ultimate users' satisfaction occurring by
the introduction of the RIS."
}