The Performance Research Of Device-to-Device System Based On Adaptive Grading MIMO Relaying Technology

With the development of mobile communication, a new type of communication technology hasbecome a research hotspot to improve spectrum utilization and reduce energy consumption,Device-to-Device (D2D) is one of the most representative technologies. It is a short distancecommunication technology. However, Due to the short communication distance, the D2D system isnot widely used in cellular networks, which can be effectively solved by the relay and multi-antennaassisted D2D communication system.The main contributions of the thesis are summarizes asfollows:(1) The performance of D2D communication with the assistance of relay and MIMO technologyis studied in this thesis. The scenario of D2D communication with the assistance of relay andMIMO technology is proposed. In this scenario, the capacity formula of D2D direct link and D2Drelay link is derived. The theoretical analysis is verified by simulation and the simulation resultsshow that the D2D system with the assistance of relay and MIMO technology can improve thesystem capacity.(2) The formula of outage probability of D2D communication system with the assistance of relayand MIMO technology in the ideal and non-ideal channel is derived, which mainly derives theformula of five kinds of links. Simulation results proves the correction of the theoretical analysisin ideal and non-ideal channel. The cellular users can communicate in D2D mode with the help ofMIMO and relay technology when they are far from each other, which can be gotten from theanalysis of system capacity and outage probability.(3) A grading algorithm based on the location of relay to solve the problem of relay selection ofmultiple D2D pairs is proposed. The research analysis shows the overall capacity varies with thechange of relay position. Then relay grading methods is proposed according to different relay mode.The simulation results show that it can reduce the number of participating relay in the selectionprocess, and reduce the relay selection time of D2D users by the effective distance determinationand the selection of graded area.