Research On Wireless Resource Management In D2D Hybrid Network

Intelligent terminal devices have also been rapidly popularized due to the development of modern wireless communication technology,which has also led to a sharp increase in the number of intelligent terminal devices.Coupled with the continuous maturity of the Internet of Things(IoTs)technology,the data traffic used by intelligent terminal devices has shown explosive growth,and the conflict between people's urgent need for high-speed data transmission and communication delays has intensified.In order to meet the growing wireless communication needs of intelligent terminal devices,Device-to-Device(D2D)communication technology based on cellular networks has been extensively studied.The D2D link can use the system's spectrum resources with cellular users in an orthogonal or non-orthogonal manner.The former is that cellular users allocate part of their own spectrum resources to D2D users to establish D2D communication,which can completely eliminate the interference between cellular users and D2D.The latter is that cellular users open their own spectrum resources to D2D users and use them together.In this way,the spectrum efficiency of the system can be significantly improved.In order to meet the urgent need for greatly improving spectrum efficiency and energy efficiency in 5G communication requirements,we have carried out research on resource allocation technology in hybrid networks where D2D communication and cellular communication coexist.The main results obtained are summarized as follows:First,a joint D2D user power control and spectrum allocation algorithm based on user QoS guarantee is proposed to solve the problem of communication resource management in the hybrid network with the coexistence of D2D communication and cellular communication.The resource allocation problem in hybrid network is modeled to ensure the communication quality of users and improve the throughput of the system.Moreover,the interference coefficients between the cellular user and the D2D user in the system are found,and the cellular communication link to be reused is selected for the D2D user according to the interference coefficients.After that,the transmission power range of the user equipment is deduced and the optimal transmission power of the D2D user is obtained to achieve the maximum throughput of the system.(2)From the perspective of the energy efficiency of the D2D users in the system,we will maximize the energy efficiency of the system under the premise of ensuring the quality of user service.Here,the D2D user first chooses to establish a direct link or a relay auxiliary link according to the location information and channel conditions.The best relay node is selected for the D2D user who has established the relay auxiliary link.In the case,the terminal transmit power is controlled to improve the energy efficiency of the system.Finally,the maximum weighted bipartite graph matching is used to maximize the energy efficiency of the system.The proposed resource allocation method has achieved a significant performance improvement in system energy efficiency.