Resource Sharing Optimization And Interference Suppression Algorithms For Device-to-Device Communication Underlaying Cellular Networks

Recently, a direct communication technology called D2D (Device-To-Device) inwhich the D2D pairs share resources with cellular network(CNs), has attracted moreand more attention by virtue of advantages it offers: cell throughput enhancement,instantaneous data rate increase, and user equipment (UE) power savings. However,this new technique poses new challenges. This article is mainly focused on theresource sharing optimization and interference suppression between D2D link andCNs.Optimum power and resource allocation are analyzed for three types of sharingmodes (orthogonal mode, non-orthogonal mode, and cellular mode), under somereasonable constraints. The expressions of sum rate are derived in all cases, except forthe cellular mode where resources are shared in the frequency domain. The numericalresults show substantial gain from this D2D communication on the traffic of wholesystem. Even with prioritized cellular communication, the gain is still prominent.With the help of paper [31], an distance limited optimization (DLO) scheme isproposed later, in which BS mustn’t know the interference channel state information:One D2D pair are sharing the same resource with the M cellular user equipments(CUEs) which are selected by the BS which has M multiple antennas.The distancesbetween CUEs and the D2D pair must be greater thanLm in.The lower bound of theergodic capacity is also derived. Numerical results show DLO and the ILA schemeproposed by paper [31] have similar performance, but the complexity of DLO is lowerthan ILA scheme.Two interference suppression schemes are discussed firstly in the fourth chapter,in which BS must know all channel state information. After that, a new scheme isproposed. The receive mode selection (suppression scheme1) introduces a new receivetechnique based on two conventional techniques, which is exploiting a retransmissionof the interference from the BS. The D2D receiver may select the most appropriatereceive technique flexibly according to the interference strength. In thedistance-constrained method (suppression scheme2), the BS selects the cellular user which is fulfilling the minimum distance constraint to share resource with D2D pair. Inthe optimal selection (the new suppression scheme), the BS selects the optimal oneamongN Ccellular users to share resource with D2D pair, after calculating andcomparing the interference strength to D2D pair. Numerical results show the outageprobability is greatly reduced as the increase ofN C, and this new suppression schemeoutperforms scheme2when N C5.