Study On Energy Efficiency Optimizing Resource Allocation Algorithms For D2D Communication In Cellular Networks

As one of the key technologies of 5G communications,Device-to-Device(D2D)is a short-distance communication technology that directly communicates data without the base station forwarding,which has broad application prospects in terms of expanding cellular communications,emergency communications,and the Internet of Things.However,in cellular and D2 D hybrid networks,D2 D users multiplexing the channels of cellular users can cause serious interference,resulting in degraded system performance and affecting battery life of the user equipment.Therefore,how to reduce interference and reduce energy consumption while multiplexing channels has become one of the key issues in the current stage of research.For the cellular and D2 D hybrid networks,the thesis studied the method that combining power control and channel assignment to suppress interference and enhance system energy efficiency.The main contents are as follows:Firstly,a hybrid network interference model was constructed to study the principle of interference in one-to-one and multiple-to-one multiplexing scenarios.Then,the influence of different factors on the system performance was analyzed through simulations,which shows that power control and channel allocation can effectively suppress interference and improve energy efficiency.Finally,the thesis compared and analyzed the existing power control algorithms and channel allocation algorithms.Secondly,aiming at suppressing the interference among cellular users and D2 D users in one-to-one multiplexing scenarios,The thesis divides resource allocation into two sub-problems: power control and channel allocation.A power allocation algorithm based on Lambert W Function and a channel matching algorithm based on Gale-Shapley method were proposed to improve the energy efficiency of D2 D users.First of all,in order to maximize the energy efficiency of D2 D users,a power allocation closure expression using Lambert W Function is deduced under the condition that the minimum SINR of cellular users is satisfied.Then,using the resulting power allocation results to maximize the SINR of cellular users and the energy efficiency of D2 D users,a resource allocation algorithm based on Gale-Shapley marriage matching is proposed to maximize users' energy efficiency,and the optimal channel allocation scheme is obtained.Simulation results show that the proposed algorithm can not only guarantee the rate of cellular users,but also improve the system energy efficiency and D2 D users' performance.Thirdly,aiming at the problem of introducing multiple D2 D users to reuse the channel resources of the same cellular user and causing system performance to deteriorate,joint power control and channel allocation,a resource allocation algorithm based on iterative combinatorial auction was proposed.Aiming at maximizing the energy efficiency of the system,the algorithm describes the solving process of the problem as an iterative combinatorial auction model,which considers D2 D users who reuse the same channel as resource package,base station as auctioneer and cellular users as auctioneers.To meet the lowest performance requirements of cellular users,the best power allocation value of D2 D users is first obtained by adjusting power stepping,and the price of resource packages is calculated.Then,the auctioneer allocates resource package to bidder with the highest bid,the optimal resource allocation plan is obtained by iteration.The simulation shows that the proposed algorithm can fully guarantee the performance of cellular users and D2 D users,and effectively improve the overall energy efficiency and transmission rate.