Energy-Efficient Transmissions for Green Base Stations With a Novel Carrier Activation Algorithm: A System-Level Perspective

A base station (BS) that enables multiple component carriers (CCs) to be jointly utilized for data transmissions is one of the most advanced cellular systems. This kind of BS aims to cope with the amazingly fast-growing demand from various users. However, such a BS is the most energy-intensive part of a cellular network because the activation of its additional CCs consumes a large amount of energy, which, in turn, causes environmental problems and higher costs for cellular operators. Consequently, how to efficiently save energy when using a multi-CC BS is an increasingly critical concern in the deployment of green cellular networks. This paper builds a practical framework for studying energy-efficient transmissions for a multi-CC BS from a system-level perspective involving both radio resource allocation and CC activation/deactivation, while also presenting several new transmission schemes for use in the multi-CC BS. In these schemes, a novel energy-saving algorithm for activating/deactivating CCs is combined with different radio resource allocation approaches, respectively. Simulation results demonstrate that these schemes have much better energy-saving performance than that of the conventional one. Furthermore, comparisons among the presented schemes are detailed.