  In this paper, a novel social network-aware user association in wireless
small cell networks with underlaid device-to-device (D2D) communication is
investigated. The proposed approach exploits social strategic relationships
between user equipments (UEs) and their physical proximity to optimize the
overall network performance. This problem is formulated as a matching game
between UEs and their serving nodes (SNs) in which, an SN can be a small cell
base station (SCBS) or an important UE with D2D capabilities. The problem is
cast as a many-to-one matching game in which UEs and SNs rank one another using
preference relations that capture both the wireless aspects (i.e., received
signal strength, traffic load, etc.) and users' social ties (e.g., UE proximity
and social distance). Due to the combinatorial nature of the network-wide UE-SN
matching, the problem is decomposed into a dynamic clustering problem in which
SCBSs are grouped into disjoint clusters based on mutual interference.
Subsequently, an UE-SN matching game is carried out per cluster. The game under
consideration is shown to belong to a class of matching games with
externalities arising from interference and peer effects due to users social
distance, enabling UEs and SNs to interact with one another until reaching a
stable matching. Simulation results show that the proposed social-aware user
association approach yields significant performance gains, reaching up to 26%,
24%, and 31% for 5-th, 50-th and 95-th percentiles for UE throughputs,
respectively, as compared to the classical social-unaware baseline.
