Design Of Device-to-Device Resource Allocation Scheme In Cellular Networks

With the rapid growth of the number of mobile devices and intelligent terminals,people put forward higher requirements on commincation systems.D2 D communication is a short-range communication technology.The basic idea of D2 D communications is that terminal devices can communicate directly with each other,and user data does not need to be transmitted by the base station.D2 D communication can effectively increase the frequency spectrum efficiency of the cellular communication system and relieve the pressure of the base station.As one of the key technologies of 5G,D2 D technology can play a great role in the applications of social network,car networking,D2 D relay,emergency communication and so on.However,the resource sharing between the cellular users and the D2 D users will also cause the co-channel interference.Therefore,an effective resource management plan is needed to solve this problem.The main works of this thesis are as follows:First,a low complexity resource allocation scheme based on auction theory is introduced to solve the resource allocation problem of a single cell where D2 D user can reuse multiple resource blocks of cellular users and one cellular user can share resource with multiple D2 D users.In this way,D2 D user groups are regarded as the bidders,and cellular resource blocks are regarded as auction products.To maximize system throughput,the scheme constructs user valuation models and utility functions.The D2 D user groups(bidders)calculate the private valuation of the cellular resources(commodities),and bid for the resources according to the maximum utility value and the sub-optimal utility value.Finally,the resources will be allocated to the highest bidder.The simulation results show that the scheme can effectively improve the system throughput on the premise of guaranteeing the communication quality of the cellular users.Then,in order to optimize the users' transmission power and coordinate the co-channel interference,a QoS-based channel assignment and power allocation scheme is analyzed.The scheme is divided into two stages.Firstly,according to the users' SINR threshold,this thesis uses a heuristic resource allocation method to get the candidate set of D2 D users.Then under the constraints of maximum D2 D transmission power and users' SINR,an objective function is constructed to maximize the total throughput of D2 D users.The optimal power allocation of D2 D users on multiple channels is solved by using Lagrange dual decomposition theory.The simulation results show that the scheme can effectively improve the performance of the system.Finally,considering the application of social network,the SCA-SM(Social Community Aware Stable Matching)is proposed.Considering the QoS requirements,maximum transmission power and social relationship between D2 D users and cellular users,the scheme controls the admission of D2 D users through the dual restrictions of physical domain and social domain.Then,the transmission power of cellular users and D2 D users is optimized.Finally,the weight lists of matching sides are established,and the Deferred-Acceptance algorithm is used for stable matching.Simulation results show that the scheme can effectively coordinate the inter user interference and increase the transmission rate.