1. School of Microelectronics and Communication Engineering, Chongqing University, Chongqing, China
2. College of Computer Science, Chongqing University, Chongqing, China
3. School of Optoelectronics Engineering, Chongqing University of Posts and Telecommunications, Chongqing, China
4. Pillar of Information Systems Technology and Design, Singapore University of Technology and Design, Singapore