Scalable interference coordination for Device-to-Device communications

Proximity based applications are becoming fast growing markets suggesting that Device-to-Device (D2D) communications is going to be an essential part of future cellular networks, thus studying the scalability of the system is of paramount importance. This paper focuses on the problem of scalability defined as finding the maximum number of D2D links that can share the same resources with cellular user equipments (CUEs) while assuring quality-of-service (QoS) to all users in cellular networks of any size. To solve this problem a careful design of interference coordination schemes is needed, thus we present two solutions namely full channel state information (CSI) optimal (F-CSIOp) scheme and partial CSI distributed (P-CSID) scheme. The first solution is based on an optimization problem that uses full CSI to maximize the number of D2D links while providing QoS to all users. However implementing this solution in real systems is infeasible due to high complexity and signaling overhead, thus we present the later solution based on a low complexity distributed algorithm that uses limited CSI. The results show that the P-CSID scheme is able to offer high spectrum efficiency and good scalability while assuring low outage probability to provide QoS for all users.