学术报告
Towards a Self-regulating Society of
Cognitive Radios
Speaker: Prof. Kai-Kit Wong
Reader in Wireless Communications, Department of EEE
University College London
Associate Editor, IEEE WCL, IEEE COMML, IEEE SPL, KICS
JCN, and IET-COM
日期：2012 年9 月5 日（星期三）
时间：上午 9：30 至10：30
地点：复旦大学计算中心楼B415 室
Abstract:
While spectrum is believed to be precious, it is actually seriously underutilized. According to
Ofcom in the UK, over 50% of locations in the UK could have more than 150 MHz of interleaved
spectrum available for cognitive access. It is Ofcom's goal to move from the traditional
exclusive-use model to a liberalization model in spectrum allocation. In this talk, I will study the
distributed resource allocation problem for an orthogonal frequency-division multiple-access
(OFDMA) interference channel in which every user is free to access any of the frequency
channels and users inherently compete and interfere with each other. I will take a game-theoretic
perspective of the channel and view the network as individuals interacting with the environment
composed of the reactions from competitors. Competition among selfish individuals is bound to
result in the tragedy of the commons, with users harmfully interfering with each other without a
proper reconciliation mechanism. Inspired by the Stackelberg leadership model of a strategic game,
I propose to inject environmental foresightedness to users by introducing the role of
environmental interference derivative in one's action (or strategy). As a major result, I will present
a physical property of the OFDMA resource allocation game which permits users to be foresighted
for a much more effective reconciliation for maximizing their rates, based on only local channel
state information (l-CSI) at the user level. The outcome is a simultaneous water-filling game
regulated by a carefully chosen operational interference derivative. Simulation results will be
provided to show that the proposed game can achieve the network sum-rate close to the
near-optimal centralized solution. The talk will be concluded by a discussion of using the strategic
game for a primary-secondary cognitive radio network.
Bio:
Kai-Kit Wong received the BEng, the MPhil, and the PhD degrees, all in Electrical and Electronic
Engineering, from the Hong Kong University of Science and Technology, Hong Kong, in 1996,
1998, and 2001, respectively. After graduation, he took up academic and research positions at the
University of Hong Kong, Lucent Technologies, Bell-Labs, Holmdel, the Smart Antennas
Research Group of Stanford University, and the University of Hull, UK. At present, he is Reader
in Wireless Communications at the Department of Electronic and Electrical Engineering,
University College London, UK.
He is Senior Member of IEEE and is also on the editorial board of several international journals
including the IEEE Wireless Communications Letters, IEEE Communications Letters and IEEE
Signal Processing Letters. His current research interests center around cognitive radio, cooperative
wireless networks, performance analysis of single and multiuser MIMO channels and
physical-layer security analysis and optimisation.
