Xin Liu (M'13-SM'19) received the M.Sc degree and the Ph.D. degree in Communication Engineering from the Harbin Institute of Technology in 2008 and 2012, respectively. He is currently an Associate Professor with the School of Information and Communication Engineering, Dalian University of Technology, China. From 2012 to 2013, he was a Research Fellow with the School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore. From 2013 to 2016, he was a Lecturer with the College of Astronautics, Nanjing University of Aeronautics and Astronautics, China.