Abstract

Cooperative communications and relaying technologies have recently attracted much attention because of the unprecedented gains, in terms of diversity order or throughput, which they can provide. As an innovative wireless system that can overcome the over allocation and under utilization of the licensed radio spectrum, cognitive radios can particularly benefit from relaying technology, not only because it can provide spatial diversity gain, but also because it can efficiently makes use of the aggregate spatially and/or geographically distributed spectrum holes. In this talk, we are going to present some state-of-the-art relaying techniques that are designed for cognitive radios. It will be shown that proper advanced coding and signal processing methods, namely, rateless coding and distributed beamforming can be adopted into cognitive relaying so as to significantly enhance the spectrum sharing ability of secondary users. We shall also talk about the mathematical tools that can optimize the overall performance of cognitive relaying from a cross-layer perspective. Finally, some recent advances on prototyping of cognitive relaying systems in China’s biggest theoretical CR research project will be presented.

Bio

Wei Chen received his BS and PhD degrees (both with the highest honors and thesis awards) from Tsinghua University, in 2002, and 2007, respectively. From 2005 to 2007, He was a visiting research staff in Department of Electronic and Computer Engineering, the Hong Kong University of Science and Technology. Since July 2007, he has been with Department of Electronic Engineering, Tsinghua University, where he is currently an Assistant Professor. Dr. Chen visited the Chinese University of Hong Kong as Sino-British Research Fellow on October, 2007, the Hong Kong University of Science & Technology from August to September, 2008/2009. From June 2010 to September 2010, he visited University of Southampton as UK-China Science Bridge Research Fellow, supported by UK Research Councils. His research interests are in the broad areas of wireless communications, information theory, and applied optimizations. In these areas, he has published over 50 papers and won best paper awards from IEEE Trans. on Wireless Communications (2008), IEEE IWCLD 2007 , IEEE ICC 2006 . He served as student travel grant chair of ICC 2008 , co-chair of IEEE CoCoNet 2008, TPC co-chair of ICC2010 Wireless Communications Symposium, and TPC co-chair of VTC 2011 , Spring. He is now serving as an editor of Communications and Networks (Scientific Research Publishing).