Rong Chen was born in 1983. She received her M.S. degree in communication and information system from Soochow University in 2009. Currently, she is working toward her Ph.D. degree at Soochow University. Her research interests include communication signal processing and cognitive radio. E-mail: chrong@ suda.edu.cn Corresponding author. Yiming Wang was born in 1956. She received her B.S. degree in electronic device and Ph.D. degree in communications engineering from Nanjing University of Posts and Telecommunications in 1982 and 2006, respectively. Now she is a professor at School of Electronics and Information Engineering in Soochow University. Her current research interests include communication signal processing, broadband wireless communications and cognitive radio. E-mail: ymwang@ suda.edu.cn