Heng Liu received the B.S. degree in electrical engineering and the Ph.D. degree in communication and information system from Beijing Institute of Technology, Beijing, China, in 2002 and 2006, respectively. Since September 2006, she has been with the School of Information and Electronics, Beijing Institute of Technology, where she is currently an associate professor. From November 2012 to December 2013, she did some research on radio tomographic imaging with wireless networks at Georgia Institute of Technology as a visiting scholar. Her current research interests include wireless localization techniques and microwave medical imaging.