Joint user association and ABS proportion optimization for load balancing in HetNet

In this paper, a user association scheme for load balancing in a downlink Heterogeneous cellular network (HetNet) incorporating almost blank subframe (ABS) for interference management is proposed. The joint user association and ABS optimization problem is formulated as maximizing a Logarithmic utility function. Since the joint optimization problem is non-convex and NP-hard, the block coordinate descent (BCD) method is employed to decouple the joint problem into two sub-problems (user association and ABS allocation) and solved in an iterative manner to obtain a suboptimal solution. Simulation results show the effectiveness of the proposed algorithm.