1. Beijing National Research Center for Information Science and Technology, Tsinghua University, Beijing, China
2. State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing, China
3. School of Electrical Engineering and Intelligentization, Dongguan University of Technology, Dongguan, China
4. Department of Electrical and Computer Engineering, University of Houston, Houston, TX, USA
5. Department of ECE, University of Waterloo, Waterloo, Canada
6. School of Information Engineering, Zhengzhou University, Zhengzhou, China