Research On The Implementation Of Base Station Controled D2D Multicast Communication Under IMT-A System

As mobile communication gradually stepped into the stage of4G (the fourth generation mobile communication), multimedia business has also grown from traditional users choosing to receive the service provider’s data to user initiated multimedia data sharing, the traditional MBMS (multimedia broadcast multicast service) technique has reflected obvious limitations applying to the new local big rate Shared business: users need to send the shared multimedia data to the base station, then data can be forwarded to the shared terminal by base station using MBMS technology, this has not only brought great pressure to the tightening spectrum resources of new generation of mobile communication, but also puts forward higher requirements on the eNB load.For this reason, this paper proposes a method to realize the D2D multicast which combines the D2D technology and MBMS technology on the basis of the D2D technology. The implementation scenario of this article specifically in order to solve the user terminal local multimedia business big rate sharing request, mobile terminals in short distances multicast data to multiple receive terminals using direct link without passing base station, it is summarized as D2MD (Device-to-Multi-Device) technology. D2MD technology combines many advantages of the D2D technology and the technology of MBMS, it can be seat under the traditional cellular network, has a good application prospect. This article first introduces the basic concept and realization method of D2D technology and MBMS technology, then the combination of both is analyzed, after that raises the D2MD technology, introduces D2MD communication from establishing to wireless resource allocation and propose a low complexity LCH algorithm which based on the user’s QOS request,finally, the link level simulation to a variety of wireless resource allocation algorithm in cellular networks is conducted.First, the paper analyzes the D2MD application scenarios and the key problems, and gives the detailed process analysis of D2MD communication from launch to implementation. Proposed the terminal paging multicast user plan and base station paging multicast user plan, analyzes the difference of signaling interaction and communication way between the two plans, and the applicable scenario of both was presented.Second, analysis the wireless resource allocation problem of all D2MD groups in a certain response period. Proposed an eNB controlled D2MD communication wireless resource allocation scheme. The scheme ensures all D2MD users quality of service (QoS) for the premise, through three steps of model selection, spectrum allocation and power control for D2MD users to allocate the wireless resource.ENB, first of all, according to the SINR limitation of D2MD receiving member and the interference limitation of cellular users to choose the base station forward mode, orthogonal mode or reuse mode, and then allocates spectrum of cellular for D2MD groups of reuse mode for their reusing, finally, conducts power control for all D2MD groups, to save terminal energy. The simulation result shows that the scheme can choose the high spectrum utilization mode for most D2MD communications, and does not affect cellular user’s communication; the result of proposed sub-optimal LCH algorithm can not only reach the same level of the uplink interference to cellular user compared to the optimal algorithm, but also can reduce the algorithm complexity and shorten the response time of the base station.