QoS-aware energy-efficient resource allocation in OFDM-based heterogenous cellular networks.

Recently, in order to satisfy the heavy demands of network capacity brought about by the proliferation of wireless devices, service providers are increasingly deploying heterogeneous cellular networks (HetNets) for boosting the network coverage and capacity. In this paper, we present an iterative energy-efficient scheduling scheme for downlink OFDM-based HetNets with QoS consideration. We formulate the problem as a nonlinear fractional programming problem aiming to maximize the QoS-aware energy efficiency (QEE) in HetNets. In order to solve this problem, we first transform it into a parametric programming problem, which takes QEE as an evolved parameter in the iterative procedure of iterative energy-efficient scheduling scheme. In each iteration, for the given value of QEE, subchannel and power assignment subproblem is a nonlinear nondeterministic polynomial time-hard problem. And hence, we adopt dual decomposition method for obtaining the optimal assignment of subchannels and power of the subproblem for the given value of QEE. Simulation results depict that both outer QEE parameter search and inner subgradient search can converge in a few iterations, and the resultant solutions outperform the equal power allocation scheme [1] and capacity maximization scheme [2] in terms of QEE. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]