ZHIKUN XU received B.S.E. and Ph.D. degrees in electrical and computer engineering from Beihang University (BUAA) in 2007 and 2013, respectively. He was a visiting researcher in the School of Electrical and Computer Engineering, Georgia Institute of Technology, from 2009 to 2010. After graduation, he joined the Green Communication Research Center of the China Mobile Research Institute as a project manager. He has published more than 20 papers in top journals and international conferences. His current research mainly focuses on 5G technologies, including energy-efficiency and spectral-efficiency co-design, large-scale antenna systems, non-orthogonal multiple access schemes, cross-layer resource allocation.