Research On User Association Strategies Of Heterogeneous Network On Utility Function

With the advent of 5G communication technology,the research on heterogeneous networks has attracted more and more attention,a lot of related works have been done.Based on the utility function,this paper studies the user association strategy,which is an important issue in heterogeneous networks,including user association strategy of network load balancing and user association strategy with optimal network energy efficiency.Firstly,a brief introduction of the basic knowledge of user association in heterogeneous cellular networks is given,expounding the basic concepts and applications of utility functions,and introducing the prior methods of user association,the basic theory of energy efficiency and the mathematical tools including convex optimization and descend method.Secondly,a user association strategy based on utility function for load balancing is proposed.We formulate it as a network-wide weighted utility maximization problem(the first load balancing algorithm).Then,each user is associated with some base stations with the max probability algorithm.Some base stations would face the overload problems resulting from the first load balancing algorithm,and the second load balancing algorithm is proposed.Experimental results show that the proposed load balancing scheme can achieve the load balancing and maintain the minimal data rate of service of users.Finally,a user association strategy based on utility function for the optimized energy efficiency of the system is proposed.We formulate it as a problem jointly considering power control and user association.Then we convert this problem into two sub-problems which are user association and power control.The first problem is solved by CVX and the second is solved by descend method.The validity and superiority of the proposed algorithm are verified by simulation.