Reasearch Of D2D-Oriented Capacity Optimization And Cooperative Security Technology In Wireless Access Network

Continuous development of mobile communication technology has made the efficient utilization problem of wireless spectrum resource and terminal energy attracting increasing attention. As a new short-range communication technology, D2D communication achieves end-to-end direct data transmission under the control of the cellular network. D2D communication in cellular networks can improve spectral efficiency and reduce terminal power consumption while reducing the burden of base station. The research subject of this paper is based on D2D communication technology in wireless access networks.This paper first analyzes the research background of the subject, elaborates the research significance of the subject, and describes the work and structure arrangement of the full text. On the basis of analyzing the research status of D2D communication technology at home and abroad, this paper focuses on the clustering technology and cooperative security technology in wireless access networks, and carries out the innovation and improvement to propose D2D clustering scheme and intra-cluster and inter-cluster eavesdropping suppression schemes.Considering the impact of the difference of device holders’interest, the diversity of social relationships and equipment capacity on D2D communication, this paper presents an admission policy based D2D clustering scheme. The process that D2D arrival users join the existing D2D clusters can be viewed as a mutual selection process between them. The proposed clustering scheme fully considers the social trust between users, physical distance, user equipment energy, interest, etc., defines two functions characterizing the attraction degree of arrival users and D2D clusters, and utilizes Chinese restaurants process to calculate the selection probobality of arrival users. In addition, this paper jointly considers the social trust of users, physical distance and energy to present D2D cluster head selection scheme. Simulation results show that the D2D clustering scheme has higher system capacity and social trust, and the cluster head selection scheme has a better reliable communications capability, which verify the efficiency of D2D clustering scheme and cluster head selection scheme.Finally, for the communication security reduction problem brought by the introduction of D2D clusters, this paper presents intra-cluster and inter-cluster eavesdropping suppression schemes. In the scenario where there only exist intra-cluster eavesdroppers, this paper proposes joint cooperative relaying and jamming scheme. Specifically, it assigns the optimal role to each relay, and designs the synchronization of the carrier signals of multiple nodes to deal with the synchronization problem in distributed beamforming. In the scenario where there exist intra-cluster and inter-cluster eavesdroppers, this paper presents an optimal relay and jammer selection scheme. By considering different services and user requirements, the scheme sets secrecy rate levels, and establishes a reasonable power allocation strategy to optimize the secrecy rate. Simulation results show that, compared to the existing schemes, the proposed eavesdropping suppression schemes have better performances in terms of improving secrecy rate and reducing energy consumption.