Research On Resource Allocation Algorithms In Radio Access Networks

In order to cope with the rapid increase in mobile Internet business and the growing demand for communication resources from a large number of users,the 5G mobile communications is facing tremendous challenges.The Cloud Radio Access Network(C-RAN)has become an important direction for the development of access networks in the future due to its advantages of cloud,centralization,cooperation,and clean.Virtualization technology can reduce the energy consumption of the Base Station(BS)system in C-RAN,and the dynamic resource allocation strategy can improve the system performance of C-RAN.Therefore,the wireless resource allocation strategy in C-RAN needs to be studied deeply.Compared with C-RAN,the Fog Radio Access Network(F-RAN)can effectively relieve the pressure on the fronthaul links and provide data transmission for high speed users.However,the huge energy consumption in F-RAN is hard to ignore.The network lifetime and energy constraints affect the performance of the network.Therefore,how to ensure the communication quality of F-RAN is still a challenging problem.At the same time,with the rapid development of energy harvesting(EH)technology,renewable energy can provide an opportunity for communication system to reduce power consumption.Under this background,the wireless resource allocation of C-RAN and the resource allocation and power grid energy consumption of F-RAN with renewable energy cooperation are mainly studied,the main contents and innovations are as follows:Aim to the inefficiency of traditional static resource allocation in C-RAN and the lack of resource type in dynamic wireless resource allocation,a dynamic wireless resource allocation scheme based on the quality of service(Qo S)constraint is proposed.Radio resources are studied from three dimensions: remote radio head(RRH)selection,subcarrier allocation and power allocation.Firstly,according to the transmission model in traditional C-RAN and Qo S constraint,an optimization problem with the variable of transmission power and the goal of throughput maximization is established.Then,the original optimization scheme is transformed to improve the system throughput by optimizing the RRH selection,subcarrier allocation and power allocation based on the improved genetic algorithm.Finally,the time complexity of the improved genetic algorithm is compared with other intelligent algorithms under the change of population size.The experimental results show that the proposed algorithm has low time complexity and the average throughput gain of the proposed resource allocation scheme is 17%.To solve the problem of substantial energy consumption in F-RAN,a resource allocation algorithm based on energy harvesting constraint is proposed by achieving joint mode selection and power allocation.First,the transmission model and energy collection model are established,and the optimization problem is established according to the constraint of power allocation and energy cost.Then,the selection of the communication mode is investigated by the branch and bound algorithm.The transmission power of different transmission modes is allocated by the throughput water-filling method.Simulation results show that the throughput and grid energy efficiency of the proposed F-RAN based on renewable energy cooperation are higher than traditional F-RAN,and it has economic and environmental benefits.