QoS-Aware Energy-Efficient Radio Resource Allocation in Heterogeneous Wireless Networks

In this paper, we investigate the energy-efficient up-link radio resource allocation scheme with quality of service (QoS) guarantees in heterogeneous wireless networks. All mobile terminals (MTs) have multi-homing capability, which can communicate with access points (APs) of the multiple radio access technologies (RATs) simultaneously. Currently, the energy efficiency (EE) is very important in the mobile communication, and become a critical metric of the radio resource management (RRM). Most of the previous studies aim to optimize the total throughput or the total power consumption. Only a few focus on energy efficiency in heterogeneous wireless networks. Thus, we formulate an energy-efficient resource allocation problem which takes the sum of energy efficiency of the MTs as the optimization object. The proposed problem is a sum-of-ratios fractional programming problem, which is NP-hard. To obtain the optimal solution, we propose an iteration-based energy-efficient resource allocation algorithm, which jointly allocates the bandwidth and the power. The proposed algorithm is divided into three stages, and the resource allocation in each stage is energy-efficient. Numerical simulation evaluates the performance of the proposed algorithm.