1. School of Electrical and Electronic Engineering, Chongqing University of Technology, Chongqing, China
2. Department of Electrical, Computer and Biomedical Engineering, Ryerson University, Toronto, Canada
3. Department of Wireless Technology, Chongqing Jinmei Communication Company Ltd, Chongqing, China
4. Department of Electronic Engineering, Chongqing University, Chongqing, China