Clustering-Based Wireless Resource Management For Heterogeneous Networks

With rapid development of wireless mobile communication,the traditional homogeneous networks do not meet the data rate requirements of users.The heterogeneous networks made up of the traditional Macrocell and new Small Cell have emerged.Small Cell has a small coverage,low transmit power,etc.,can be installed in the indoor and outdoor scenes to fill Macrocell coverage blind spot,and improve the capacity of wireless networks.However,when the Small Cell is heavily deployed within the Macrocell,a very serious interference exists because Small Cell and Macrocell share the whole spectrum,such as cross-tier interference between Small Cell and Macrocell,and co-tier interference among Small Cell.For example,Femtocell is a typical Small Cell.This paper mainly studies the resource allocation problem in ultra-dense heterogeneous networks formed by the combination of Femtocell and Macrocell,and introduces two resource allocation schemes to avoid interference while improving system capacity and spectrum utilization.The main research contents include the following two aspects.First,in order to alleviate the cross-tier interference and the co-tier interference in the ultra-dense heterogeneous network,a cluster-based resource management scheme is proposed.The proposed scheme includes two parts: In the first part,the three-round sub-channel allocation algorithm is adopted to assign sub-channels to the macro users,and then the power is allocated in Water-Filling fashion.In the other part,Femtocells are divided into disjoint groups by improved Genetic Simulated Annealing Algorithm,and then Femtocells perform sub-channel and power allocation by Heuristic algorithm and Karush-Kuhn-Tucker condition.Simulation results show that the proposed scheme effectively suppresses these two kinds of interference in the network,not only satisfies the data rate requirements of users,but also improves the spectrum efficiency.Second,in order to solve the interference management problem and resource allocation problem in heterogeneous networks,we employ a hybrid spectrum allocation approach whereby the spectrum is split between the Macrocell and its nearby interfering Femtocells based on their resource requirements,whereas the distant Femtocells share the entire spectrum with the Macrocell.Then the joint power and subchannel allocation scheme is adopted to assign resource and power for Femtocell in each cluster.The simulation results show that the proposed algorithm can effectively suppress the interference,improve the system capacity,and take into account the fairness among users,also get a satisfactory system performance.