Opportunistic interference alignment approach in device-to-device communications underlaying cellular networks

Abstract

We consider Device-to-Device (D2D) communications underlaying cellular networks with multiple cellular users (CUs) and multi-pair direct D2D users (DUs). In this considered scenario, we propose a novel opportunistic interference alignment (OIA) scheme to improve the sum rate of the whole networks. DUs are opportunistically selected based on the reference signal space (RSS) of the CUs. According to the RSS, the DUs can calculate the scheduling metric which represents the strength of D2D interference to CUs. Then, we select the DUs according to the computing result. Unlike most of the existing methods, the proposed OIA scheme relies on the local channel state information, which is more realistic in practice. In addition, in view of the angle between the interference caused by each DU and the RSS, several scheduling strategies are designed to enhance the performance. Numerical results show that the proposed scheme can improve the performance of the network.