The widespread demand for high rate multimedia wireless communications has drastically increased the power consumption of wireless networks. However, the advances in battery technology have not kept pace, resulting in a severe mismatch between the energy thirst and battery capacity of mobile units. The major objective of this research is to develop energy-efficient techniques for robust and secure wireless networks through distributed optimization of cross-layer network design.
This research performs a comprehensive investigation into energy-efficient wireless communications. In wireless networks, the channel conditions of users, at different locations, times, and frequencies are different. The quality of service and network efficiency can be significantly improved if these differences can be exploited. Since all protocol layers impact energy consumption, the investigators will develop cross-layer energy-efficient techniques to reduce redundant message transfers and the associated energy consumption. This research will focus on energy-efficient transmission and resource allocation strategies that are amenable to applications in wireless OFDM and MIMO systems, and emphasize energy efficiency over peak rates. To enhance energy efficiency for wireless networks, novel approaches and techniques based on new performance criteria for integrative network optimization will be investigated. Key energy considerations for developing cross-layer network media access protocols and resource allocation algorithms will be integrated into the new framework.
During the period of the NSF grant, w e have investigated various energy efficiency (EE) designproblems, such as EE design in OFDMA, MIMO, distributed antenna systems (DAS), relaying, andHetNets, and have achieved fruitful research findings. In total, w e have published/submitted 17journal papers and 16 conference papers. We have given presentations and tutorials at IEEEconferences. We have created a w ebsite for public access of our research findings. Ourresearch findings cover broad areas of w ireless communications, espicially in PHY and MAClayers, and can be roughly divided into the follow ing six categories:-EE survey, tutorial and open issues (2 journal papers)-EE design in OFDMA (7 journal papers and 7 conference papers)-EE transmission in relay/cooperative systems (2 journal papers and 2 conference papers)-EE enhancement in MIMO (3 journal papers and 3 conference papers)-EE design in DAS (2 journal papers)-Others EE topics (HetNet, fundamental issues .etc) (1 journal paper and 2 conference papers)With all the research findings in these areas, w e have revealed the fundamental properties andthe benefits of EE design and show n how to improve EE in w ireless communications throughcross-layer optimization. Our research findings have made significant impact on EE w irelesscommunication and have been highly acknow ledged and cited by the IEEE community. Forexample, our tw o survey papers "A survey of energy-efficient w ireless communications" and"Energy-efficient w ireless communications: tutorial, survey, and open issues" have both beenrecommended as one of the "Best Reading Topics on Green Communications" by IEEEvia http://w w w .comsoc.org/best-readings/topics/green . Our paper "Energy efficiency ofcooperative beamforming in w ireless ad-hoc netw orks" has been aw arded the Best PaperAw ard at IEEE 2012 International Communications Conferences (ICC'12). In addition, our researchfindings have also inspired the engineering/industry field of w ireless communications.Our research findings also contributes to the reduction of energy consumption and hazardousbattery w aste. It w ill help to build a clean and green energy future and makes our w irelesscommunications environmentally sustainable
