Title :
Energy- and Spectral-Efficiency Tradeoff in Downlink OFDMA Networks
Author :
Xiong, Cong ; Li, Geoffrey Ye ; Zhang, Shunqing ; Chen, Yan ; Xu, Shugong
Author_Institution :
Sch. of ECE, Georgia Inst. of Technol., Atlanta, GA, USA
Abstract :
Conventional design of wireless networks mainly focuses on system capacity and spectral efficiency (SE). As green radio (GR) becomes an inevitable trend, energy-efficient design in wireless networks is becoming more and more important. In this paper, the fundamental tradeoff relation between energy efficiency (EE) and SE in downlink orthogonal frequency division multiple access (OFDMA) networks is addressed. We obtain a tight upper bound and lower bound on the optimal EE-SE tradeoff relation for general scenarios based on Lagrange dual decomposition, which accurately reflects the optimal EE-SE tradeoff relation. We then focus on a special case that priority and fairness are considered and derive an alternative upper bound, which is even proved to be achievable for flat fading channels. We also develop a low-complexity but near-optimal resource allocation algorithm for practical application of EE-SE tradeoff. Numerical results demonstrate that the optimal EE-SE tradeoff relation is a bell shape curve and can be well approached with our resource allocation algorithm.
Keywords :
energy conservation; frequency division multiple access; quality of service; radio networks; resource allocation; EE tradeoff; GR; QoS; SE tradeoff; downlink OFDMA network; downlink orthogonal frequency division multiple access network; energy-efficiency tradeoff; green radio; quality-of-service; resource allocation scheme; spectral-efficiency tradeoff; tight lower bound; tight upper bound; wireless network; Downlink; Optimized production technology; Real time systems; Resource management; Throughput; Wireless networks;
Conference_Titel :
Communications (ICC), 2011 IEEE International Conference on
Conference_Location :
Kyoto
Print_ISBN :
978-1-61284-232-5
Electronic_ISBN :
1550-3607
DOI :
10.1109/icc.2011.5962777