DocumentCode :
1637414
Title :
Energy-efficient link adaptation for cognitive radios with heterogeneous QoS requirements
Author :
Erqing Zhang ; Sixing Yin ; Liang Yin ; Shufang Li
Author_Institution :
Sch. of Inf. & Commun. Eng., Beijing Univ. of Posts & Telecommun., Beijing, China
fYear :
2013
Firstpage :
263
Lastpage :
268
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.
Keywords :
cognitive radio; energy conservation; nonlinear programming; quality of service; radio spectrum management; radiofrequency interference; PU interference constraint; bisection method; cognitive radios; convex optimization theory; delay-sensitive SU; delay-tolerant SU; dual decomposition method; energy consumption; energy efficiency; energy-efficient link adaptation; equivalent parametric programming problem; heterogeneous QoS requirements; heterogeneous quality of service; interference-limited CR system; joint subcarrier assignment; nonlinear fractional programming problem; optimal solution; power allocation; secondary users; spectrum sensing; system throughput; wireless communication systems; Delays; Interference; OFDM; Optimization; Programming; Quality of service; Resource management;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Cognitive Radio Oriented Wireless Networks (CROWNCOM), 2013 8th International Conference on
Conference_Location :
Washington, DC
Type :
conf
DOI :
10.1109/CROWNCom.2013.6636828
Filename :
6636828
Link To Document :
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