Research On The Radio Resource Allocation Algorithms For LTE-A System

The lack of radio resource in mobile communication system leads to the importance of resource allotcaion in the aspect of system performance.With the rapid development of the wireless networks and the explosive grown of multimedia applcations,the contradiction had been inevitably aggravated between the limited wireless resource and the increasing Quality of Servce(Qo S)requirements of multimedia severce.To alleviate this contradiction,the radio resource allocation has been made as one of the core issues for the research on mobile communication systems.Multi-carrier communication technology has received a great deal of attention for its potential high data rate transmission over multipath fading channels and high spectral efficiency.By now,orthogonal frequency division multiplexing(OFDM),representing the multi-carrier communication technology,has been successfully utilized in many wireless communications systems.Meanwhile,LTE/LTE-Advanced systems introduce a variety of key technologies,such as Multiple Input Multiple Output(MIMO)technology,Coordinated Multiple Point Transmission/Reception(CoMP)transmission and Device-to-Device(D2D)communication,to achieve the goal that supporting a wider range of communication service such as high data rate,large capacity and broad coverage.Aiming at the multi-user and multi-service dynamic resource allocation problem in multi-carrier communication system,this dissertation studies the dynamic resource scheduling,cross-layer optimization and downlink power allocation algorithm in the process o f resource allocation.In LTE-Advanced system,Qo S guarantee,system resource utilization and fairness of the system performance are analyzed.The specific work is as follows:Firstly,according to the wireless dynamic resource scheduling requirements for QoS of different service types in LTE-Advanced systems,many researches only discuss the optimal performance of the system under certain scenarios currently.An adaptive dual-mode resource scheduling algorithm with universality is proposed in this dissertation.The scheduling algorithm can be applied to different system performance objectives by reducing the parameters of user priority,transmission delay and mode switching weight factor.It reduces the Qo S of individual services for system resource utilization and fairness and simplifies the complexity of the mode switching process to meet the performance requirements of different system s.The simulation analysis on LTE-Advanced scenario shows that the proposed algorithm can effectively guarantee the delay budget based on the QCI level of each service,and obtain a good compromise between Qo S guarantee,system resource utilization and fairness.Based on different application scenarios and system performance objectives,this algorithm adjusts the compromise,which has a wider application space.Secondly,in this dissertation,according to the rate control problem of elastic business in the LTE-Advanced system network,a resource allocation algorithm based on cross-layer policy is proposed to adaptively adjust the rate of serv ices based on the demand of flexible services with the controllable rate of the network and the resource status.Therefore,the cross-layer strategy is adopted to optimize the application layer and the MAC layer and the physical layer to maximize the utility of the elastic business flow in the system.Then,the decomposition problem is decomposed into the rate control sub-problem and the subcarrier power allocation sub-problem.The sub-problem of the rate control is solved by the convex optimization method.The sub-problem of resource allocation is solved by the duality domain transformation and iterative solution.Simulation analysis on the LTE-Advanced scenario shows that the cross-layer optimization not only has higher network service utility than the maximum throughput algorithm,but also achieves the rate control to satisfy the users' demand.Finally,according to the sense that more complex multi-users and various Qo S requirements exist simultaneously,a genetic algorithm-based downlink resource allocation algorithm for multi-users and various Qo S requirements is proposed,and the algorithm can meet the Qo S requirements and fairness requirements of various services as much as possible.Maximizing system utility model is applied to research downlink resource allocation problem.In this algorithm,the utility function of the research object is set up,and the user utility corresponding to the resource in the system is mapped into the visualized numerical index.The user utility and the maximization are taken as the optimization target of the research problem.The genetic algorithm in intelligent computing is applied to solve the resource allocation model.Simulation analysis on LTE-Advanced scenario shows that the system throughput and system utility of the proposed genetic algorithm is significantly higher under the requirement and the service requirements of QoS users and BE users than the cooperative power allocation algorithm to ensure that all users of the service needs of the business,with great system performance advantages.Dynamic resource scheduling,cross layer optimization and downlink power allocation algorithm gradually discusses the wireless resou rce allocation problem in multi-carrier communication systems,in LTE-Advanced scenarios simulation analysis results show that the proposed algorithm can improve system resource utilization,fairness and QoS security performance.Resource allocation algorithm is proposed in this dissertation according to the multi-carrier system,although the process simulation in LTE-Advanced system scenarios,but the algorithm is mainly discussed the problem of resource allocation in different bu siness requirements under multi-carrier system,this work has the potential for multi carrier communication systems such as 5G and other aspects of the future application a theoretical basis.