  Employing channel adaptive resource allocation can yield to a large
enhancement in almost any performance metric of Device-to-Device (D2D)
communications. We observe that D2D users are able to estimate their local
Channel State Information (CSI), however the base station needs some signaling
exchange to acquire this information. Based on the D2D users' knowledge of
their local CSI, we provide a scheduling framework that shows how distributed
approach outperforms centralized one. We start by proposing a centralized
scheduling that requires the knowledge of D2D links' CSI at the base station
level. This CSI reporting suffers from the limited number of resources
available for feedback transmission. Therefore, we benefit from the users'
knowledge of their local CSI to develop a distributed algorithm for D2D
resource allocation. In distributed approach, collisions may occur between the
different CSI reporting; thus a collision reduction algorithm is proposed. We
give a description on how both centralized and distributed algorithms can be
implemented in practice. Furthermore, numerical results are presented to
corroborate our claims and demonstrate the gain that the proposed scheduling
algorithms bring to cellular networks.
