Energy-efficient resource allocation in macrocell-smallcell heterogeneous networks

Cellular users in indoor environments have difficulty to enjoy high rate services from Macro Base Station (MBS) due to the penetration loss. Smallcell, as a complement to Macrocell, can enhance the coverage by constituting heterogeneous network (HetNet). HetNet has been investigated as a promising technique and is considered as a candidate for green communications. However, interference in HetNet is an emergency issue. In this paper, an energy-efficient subchannel and power allocation scheme for a downlink of Macrocell-Smallcell HetNet is proposed. The resource allocation problem to maximize the Energy Efficiency (EE) for all Smallcell Base Stations (SBSs) is formulated as a non-convex optimization problem with the condition of the guaranteed data rate and the cross-tier interference constraint. The problem is transformed into an equivalent form which can be solved by an iterative algorithm. The dual decomposition method is utilized in each iteration to obtain the closed-form solution for the optimal power and resource block allocation. Simulation results show that the proposed EEmax algorithm outperforms the resource allocation algorithm of total capacity maximization in the performance of energy-efficient with a bit of little cost of spectrum efficiency. © 2016 Journal of Communications.