Research On Network Controlled Device-to-Device Communication Technologies In LTE-A

With the advent of mobile Internet and the popularity of intelligent terminals, thefuture mobile communication will present two characteristics. On the one hand, thecapacity of traditional cellular network will undoubtedly be challenged, as the require-ments for communications are growing fast. On the other hand, traditional cellularcommunication mode seems in low efciency for the emerging applications in prox-imity. Device-to-Device (D2D) is a novel communication technology which allows fordirect communication between terminals without the involvement of base station (BS).D2D communication can share the cellular resource in orthogonal and multiplexingmanner, and transfer the data link from core network to direct link. Therefore, D2Dcommunication is not only a best way to serve communications in proximity, but alsocan reduce network load, as well as improve spectrum efciency. In this paper, net-work controlled D2D communication technology in LTE-A system has been studied.We frst introduce the related background knowledge, and then make some analysis toresource sharing and interference problem on D2D communication. Then we main-ly focus the research on two fundamental problems. One is spectrum resource man-agement for D2D communication in orthogonal manner, and the other is interferencecoordination for D2D communication in multiplexing manner.On the research of spectrum resource management for D2D communication inorthogonal manner, we consider how to allocate resources for D2D communicationdynamically. Firstly, we focus on the problem about reusing resources between D2Dlinks. It is possible to group the D2D links and each group occupies same resourceswithoutbringinginanyinterferenceastheircharacteristicsofproximityandlowpower.The number of groups will be minimized by the proposed greedy grouping algorithm so as to maximize the spectrum efciency of D2D network. Then, we focus on theproblem about allocating resources to the pool of D2D communication dynamically.Considering the throughput revenue of D2D links and cellular links, we formulate theoptimization problem to maximize total throughput revenue, and put forward a dis-tributed solution based on evolutionary game theory. Finally we propose a dynamicresource allocation scheme based on the aforementioned procedure. The simulationresults show the scheme can signifcantly improve the system spectrum efciency, andalso can adapt to the dynamic changes of network.On the research of interference coordination for D2D communication in multi-plexing manner, we consider how to coordinate the mutual interference between D2Dlinks and cellular uplinks when they use same resources, to maximize the number ofreliable D2D links in system while prioritizing to maintain the cellular communica-tion. Firstly, we formulate the interference coordination problem based on resourceallocation. And then, we come up with a solution based on graph theory to properlyreuse the cellular resource for D2D links, as well as control the transmit power of D2Dlink to improve the sum data rate. Finally, we propose an interference coordinationmechanism based on the aforementioned solution, and also accomplish the design ofsignaling interaction. We efciently accommodate our proposed scheme into the setupprocess of D2D link in LTE-A system. The simulation results show that our proposedscheme can efciently coordinate the interference to enhance the number of reliableD2D links in system, as well as improve the system spectrum efciency.