DocumentCode :
2986014
Title :
Energy Efficiency Optimization in OFDM-Based Cognitive Radio Systems: Impact of Power Amplifiers
Author :
Xinxin Shi ; Wenjun Xu ; Xuemei Zhou ; Jiaru Lin
Author_Institution :
Key Lab. of Universal Wireless Commun., Beijing Univ. of Posts & Telecommun., Beijing, China
fYear :
2015
fDate :
11-14 May 2015
Firstpage :
1
Lastpage :
5
Abstract :
Nowadays energy efficiency (EE) of wireless communication systems has become a hot issue, yet the nonlinear effect and inefficiency of power amplifier (PA) have posed practical challenges for system designs to achieve high EE. However, most of previous work only considered linear PA. In this paper, we studies EE optimization concerning with I-way Doherty PA which has widespread use with I = 1 and I = 2 in orthogonal frequency division multiplex (OFDM)-based cognitive radio (CR) systems. The aim is to maximize EE with nonlinear PA subject to the total power budget, the interference constraint and the minimum rate requirement. Other than traditional methods, the problem is hard to solve directly due to the nonlinearity of PA, and a bisection search method tailored for nonlinear PA is adopted to achieve the sub-optimal solution. Numerical results demonstrate that if the PA´s nonlinearity is not considered, the EE performance of OFDM-based CR systems can be severely overestimated by 34% at P max out = 80 W for 1-way Doherty PA. Meanwhile, the EE performance can be enhanced by approximate 32% if 2-way Doherty PA is utilized instead of 1-way Doherty PA.
Keywords :
OFDM modulation; cognitive radio; energy conservation; numerical analysis; power amplifiers; telecommunication power management; Doherty power amplifier; OFDM; cognitive radio systems; energy efficiency optimization; nonlinear effect; orthogonal frequency division multiplex; power 80 W; wireless communication systems; Algorithm design and analysis; Cognitive radio; OFDM; Optimization; Power demand; Resource management;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Vehicular Technology Conference (VTC Spring), 2015 IEEE 81st
Conference_Location :
Glasgow
Type :
conf
DOI :
10.1109/VTCSpring.2015.7145806
Filename :
7145806
Link To Document :
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