Research On D2D Cooperative Communication Resource Management Scheme Based On Joint Power Allocation

With the massive access of smart mobile devices and the accelerated popularization of emerging wireless communication services,mobile data traffic has exploded,and users have increasingly higher data rate requirements,5G's key technologies D2D(Device-to-Device)communication technology and relay cooperation technology came into being,this thesis mainly analyzes the problems of complex co-channel interference,spectrum resource allocation,relay selection,and energy consumption caused by the heterogeneous network and the introduction of relay cooperation technology into heterogeneous network.The main research work is summarized as follows:1.Aiming at the problems of low spectrum resource utilization and serious co-channel interference in the heterogeneous network composed of cellular users and D2 D users,a new resource management scheme is proposed.In order to control the interference of base station in the case where the cellular user is reused by the D2 D user,the concept of protection area of base station is proposed.Then,by grouping D2 D users outside the protected area,mutual interference between D2 D user links is reduced,and a scenario in which multiple D2 D users reuse a cellular user's uplink spectrum resource communication is achieved.Finally,the cellular users are selected to reuse their spectrum resources for each D2 D user group based on the outage probability.Simulation results show that the algorithm can not only effectively reduce co-channel interference between users,but also allow more D2 D users to access,and improve system throughput and fairness.2.Aiming at the problem that D2 D users have poor channel quality and cannot communicate directly,this paper proposes a relay selection algorithm for joint mode selection and resource allocation.Firstly,determine whether D2 D users need relay,and select communication mode according to the judgment result.Then adjust the geographic location and remaining energy factors of idle users by weight to intelligently select the optimal relay for users who need relays.Finally,optimal spectrum resources are selected for the two hop communication links based on the first-level sealed bid auction mechanism.Simulation results show that the algorithm proposed in this paper compare with the algorithm of selecting relays to maximize system throughput based on area division,is not only meets the actual requirements,but also can expand the network coverage and improve the system throughput.3.Aiming at the problems of co-channel interference caused by D2 D communication and limited battery energy of mobile devices.Based on cognitive user network,this paper proposes a power allocation algorithm for joint resource management to maximize system energy efficiency by analyzing relay-assisted D2 D user communication system.Firstly,based on cognitive radio technology to perceive the available spectrum,combined with the proposed restricted area criteria,adaptively select the reusable spectrum resources of the two hop D2 D communication links,and effectively coordinate the co-channel interference.Secondly,while guaranteeing users communication quality,by transforming non-linear fractional planning into non-linear parameter planning,the optimal transmission power ranges of cellular users,relay users,and D2 D users are deduced,thereby efficiently using limited battery energy.Simulation results show that the proposed algorithm can not only expand the coverage of D2 D communication,but also effectively improve the energy efficiency of the system to achieve green communication.