Joint User Association and Resource Allocation for eICIC with QoS Provisioning in HetNets

The heterogeneity between macro and pico base stations (BSs) and the uneven traffic distribution bring challenges for the load balancing and interference coordination in heterogeneous networks (HetNets). Besides, how to guarantee the quality of service (QoS) requirement of pico users when the heavy traffic is offloaded from macro BSs to pico BSs is also a problem worth considering. In this paper, we jointly consider macro user offloading strategy, almost blank subframes (ABS) ratio configuration and resource allocation scheme to deal with the above difficulties, where ABS is a feasible way for enhanced inter-cell interference coordination (eICIC). Specifically, we first formulate a joint user association and resource allocation problem for eICIC with QoS provisioning, and then use the Gauss-Seidel method to decouple the joint problem to three subproblems and solve them in an iterative manner. Furthermore, we propose a heuristic algorithm with low complexity based on the intermediate analytical results. Comparing the proposed scheme with the cell range expansion (CRE) scheme, significant edge throughputs and fairness gains are observed in the simulations.