Research Article
Energy-Efficient Link Adaptation for Cognitive Radios with Heterogeneous QoS requirements
@INPROCEEDINGS{10.4108/icst.crowncom.2013.252012, author={Erqing Zhang and Sixing Yin and Liang Yin and Shufang Li}, title={Energy-Efficient Link Adaptation for Cognitive Radios with Heterogeneous QoS requirements}, proceedings={8th International Conference on Cognitive Radio Oriented Wireless Networks}, publisher={ICST}, proceedings_a={CROWNCOM}, year={2013}, month={11}, keywords={cognitive radio energy efficiency link adaptation qos convex optimazation}, doi={10.4108/icst.crowncom.2013.252012} }- Erqing Zhang
Sixing Yin
Liang Yin
Shufang Li
Year: 2013
Energy-Efficient Link Adaptation for Cognitive Radios with Heterogeneous QoS requirements
CROWNCOM
IEEE
DOI: 10.4108/icst.crowncom.2013.252012
Abstract
Energy efficiency is crucial in wireless communication systems, especially in cognitive radio (CR) systems in which the exclusive functionality of spectrum sensing inevitably incurs additional energy consumption. In this paper, we study energy-efficient link adaptation for the secondary users (SUs) with heterogeneous quality of service (QoS) requirements in an interference-limited CR system. Two classes of SUs with different QoS are considered: delay-sensitive SUs (DS-SUs) and delay-tolerant SUs (DT-SUs). We focus on energy efficiency (EE) maximization taking into account the SUs’ heterogeneous QoS and PU interference constraint. The problem of EE maximization is formulated as a nonlinear fractional programming problem, which is transformed into an equivalent parametric programming problem. Moreover, optimal solution to joint subcarrier assignment and power allocation is derived with the bisection method and dual decomposition method (DDM) in convex optimization theory. Simulation results illustrate the significant performance improvement of our scheme over an existing one which aims at maximizing system throughput rather than EE.