A resource allocation scheme for device-to-device communications using LTE-A uplink resources

Device-to-device (D2D) communications enabling devices to directly communicate with each other have been considered to overcome the shortage of available radio resource and reduce heavy traffic load on cellular base station. D2D communications operating on cellular networks can improve the efficiency of utilizing radio resource by reusing the resource of cellular networks. However, it can cause interference between cellular and D2D entities using the same resource, and the interference may degrade the performance of the entire system. D2D communications have been preferred to use uplink (UL) resources of cellular networks due to asymmetric UL and downlink (DL) service loads. In Long Term Evolution Advanced (LTE-A), single carrier frequency division multiple access (SC-FDMA) has adopted as UL transmission scheme in order to achieve low a high peak-to-average power ratio (PAPR). There are the exclusivity and the adjacency constraints in SC-FDMA. In order to enable D2D communications to efficiently reuse UL resources of the cellular networks, a radio resource allocation scheme with the constraints of SC-FDMA is proposed in this paper. The proposed scheme pairs up a cellular user equipment (CUE) and a D2D pair as a resource sharing pair (RSP) by controlling transmission power of D2D user equipments (DUEs), and allocates the contiguous subchannels to an RSP based on the well-known proportional fairness (PF) scheduling algorithm. The results of performance evaluation show that the proposed scheme can maintain throughputs of CUEs and alleviate the high PAPR problem of user equipments (UEs).