Reconfiguration Of Energy/Spectral Efficient Wireless Communication Networks

Traditional wireless communication systems focus on Spectral Efficiency (SE)with excessive energy consumption. With widespread attention on global warming andexcessive energy consumption, system designers began focusing on energy efficiencyinstead of the traditional spectral efficiency. The newly green cellular systems focus onEnergy Efficiency (EE) with average data rates. A system that maximizes either spectralefficiency or energy efficiency without taking into account the variation of traffic loadwill lead to poor system performance in terms of outage probability, throughput,spectral efficiency or energy efficiency. In addition, spectrum and energy are differentresources and current cellular system cannot figure out an effective way to allocationthem fairly.To address these issues, in this paper we first propose a Dynamic Traffic-awareReconfiguration (DTR) scheme, aiming at maximizing the average system EE whileguaranteeing the required system performance. Then we propose the Game TheoreticalReconfiguration (GTR) scheme which guarantees the proportional fairness of SE andEE.DTR is fulfilled by reconfiguring the system to SE, EE or hybrid SE-EE systemaccording to the traffic load. Specifically, when traffic load is heavy, we configure thesystem to be SE while when traffic load is light, we reconfigure it to be EE. Whentraffic load is medial, DTR reconfigures the system according the required systemperformance. The key criterion for reconfiguring the system is the outage probability,which is estimated through using a queuing model. We implemented DTR scheme in3GPP LTE system level simulator and conducted intensive simulation experiments tovalidate the effectiveness of our proposed DTR scheme. Numeric results show that DTRcan maximize the average EE while guaranteeing the system performance compared topure SE or EE system.GTR looks insight of the network reconfiguration problem by adopting theclassical game theory. In GTR, a new game model which allows the system to treatspectral efficiency and energy efficiency fairly and effectively is proposed. In this proposal, SE and EE are treated as two virtual players of a Nash Game. Throughgaming, we can make sure that SE and EE can be proportionally fair. We simulated ouralgorithm on the LTE system level simulator and experimental results show that thisalgorithm can achieve proportional fairness on SE and EE.