Research On Interference Management Of Multi Cell D2D Communication In LTE-A System

How to effectively improve the network capacity and spectrum efficiency is considered as a hot issue in the research field of wireless mobile communication, under the architecture of existing cellular network. D2D(Device-to-Device) communication is seen as one of the important technologies to enhance the network capacity and spectrum efficiency, when it works in the multiplex mode, the key issue is interference management. However, the research of interference management is mainly concentrated on the single cell by far, and few works research on the multi cell yet. Therefore, the thesis focuses on the issue of interference management of D2 D communication system. The concrete research contents are as follows:1. In view of the interference in multi cell D2 D communication system, this thesis study a multi cell D2 D interference management algorithm which based on non cooperative game theory. While the traditional Round Robin scheduling is still applied in the resource allocation of cellular users. The game players are determined through the analysis of interference in multi cell D2 D system firstly. Subsequently, by a novel pricing mechanism, a non-cooperative power control game model with interference factors is established, and the existence and uniqueness of power utility function's Nash Equilibrium Point are verified as well. Ultimately, the reasonable transmission power of each D2 D communication link is obtained by the continuous iteration of transmission power. Simulations show that, the proposed algorithm can raise the users fairness effectively, and reduce the system interference while enhance the cell throughput.2. Aiming at the problems of bad channel quality caused by cross-cell D2 D communication link due to the factors of distance or obstacles in multi cell scenario, the relay technology is introduced, which exploits the idle cellular user to serve as a relay so as to establish a two-hop communication link. Based on the analysis of the interference of two-hop D2 D link with relay, a joint resource optimization algorithm is investigated, which can reduce the interference caused by cellular users by selecting the appropriate resource blocks. With the goal of rate maximization, a joint optimization model is established, and the dual decomposition theory is introduced for analysis. Ultimately, the joint optimization of power control and resource allocation is achieved by the iteration of transmit power and Lagrange factor respectively. Simulation results show that both the link rate and throughput of end-to-end path can be improved effectively.