A Novel Approach for QoS-Aware Joint User Association, Resource Block and Discrete Power Allocation in HetNets

We consider joint optimization of user-to-basestation (BS) association, and time-frequency resource block (RB) and power allocation in heterogeneous networks (HetNets). The objective is to develop a design: 1) that maximizes the number of users accommodated in the network while satisfying their quality of service (QoS) demands; and 2) that minimizes usage of the resources required to meet these demands. We investigate two novel instances of HetNets with opportunistic RB-reuse. In the first instance, user-to-BS associations, and power allocations can be time-shared, and the RBs can be reused during the signalling interval. For this instance, it is shown that the design problem can be approximated by a problem that yields tight convex upper and lower bounds on the objective. In contrast, the second instance represents a case in which the RBs can be reused, but the userto- BS associations, and power allocations are not time-shared, and hence, fixed throughout the signalling interval. The latter case gives rise to a combinatorial optimization problem, which we provide an approximate solution for by using a polynomialcomplexity t