QoE and energy efficiency aware resource allocation for OFDM systems in group mobility environments

The global information and communication technology industry is a fast growing contributor to the electrical energy consumption, especially for the base stations, accounting for a substantial amount of the energy use. Inherently, a resource allocation strategy including subchannels blackout would reduce energy consumption. In this paper, energy efficient resource allocation algorithms are addressed for the OFDM system in group mobility environments, suffering from high intercarrier interference. We first propose the subchannels blackout scheme to save energy implicitly without performance degradation by turning off certain subchannels when transmitting signals. Then, resource allocation scheme in combination with subchannels blackout scheme is developed, consisting of intergroup subchannels allocation and inner-group subchannels blackout. Its advantage is twofold. i Energy consumption is reduced obviously; ii intercarrier interference is decreased and channel quality is enhanced simultaneously. However, the original transmit rate decreases with the decrease of active resources. We also prove under subchannels blackout scheme, achieved throughput and perceptual quality of experience QoE are quasiconcave in energy saving percentage, which reflects the number of blackout subchannels. We then present two energy efficient resource allocation algorithms. Both algorithms focus on the optimal solution by using an iteration method. The difference lies in the objective. One tries for energy consumption minimization above the satisfactory QoE level, but the other aims to maximize QoE perceived by users. Numerical results confirm the theoretical findings and demonstrate the promising energy-saving capability with satisfying QoE of the proposed resource allocation schemes. Copyright © 2013 John Wiley & Sons, Ltd.