Joint resource allocation and power control for CoMP transmissions in LTE-A HetNets with RRHs

In this paper, we investigate the problem of joint coordinated resource allocation and power control for LTE-A heterogeneous networks (HetNets) with low-power remote radio heads (RRHs). The scenario we consider is the configuration when RRHs share the same cell ID with the macro BS such that coordinated multi-point (CoMP) operations among transmission points can be performed in a finer granularity without undesirably triggering frequent handover operations. We first formulate a mixed-integer non-linear (MINLP) optimization problem involving multiple transmission points and a set of users demanding fair service. To reduce problem complexity, we transform the formulation into a coordinated scheduling problem with transmission power control. We then propose a two-phase iterative algorithm involving sub-channel resource allocation and co-channel power allocation for solving the target problem. Simulation results show that RRHs with CoMP operations do provide a promising approach for enhancing the performance of users in the macrocell and the proposed algorithm can effectively solve the problem with noticeable performance gain.