Weikai Xu received the B.S. degree in electronic engineering from Three Gorges College, Chongqing, China, in 2000, the M.Sc. degree in communication and information system from the Chongqing University of Posts and Telecommunications, Chongqing, China, in 2003, and the Ph.D. degree in electronic circuit and system from the Xiamen University of China, Xiamen, China, in 2011. From 2003 to 2012, he was a Teaching Assistant, and Assistant Professor in Communication Engineering of Xiamen University. He is now an Associate Professor in Information and Communication Engineering of Xiamen University. Dr. Xu’s research interests include chaotic communications, underwater acoustic communications, channel coding, cooperative communications and ultra-wideband. He has published nearly 20 IEEE journal papers. He has been serving as a reviewer for IEEE Transactions on Communications, IEEE Transactions on Vehicular Networks, IEEE Wireless Communication Letters, and so on.