1. State Key Laboratory of Advanced Rail Autonomous Operation, the School of Electronics and Information Engineering, the Frontiers Science Center for Smart High-speed Railway System, the Beijing Engineering Research Center of High-Speed Railway Broadband Mobile Communications, Beijing Jiaotong University, Beijing, China
2. State Key Laboratory of Advanced Rail Autonomous Operation, Beijing Jiaotong University, Beijing, China
3. Department of Electrical and Computer Engineering, University of Houston, Houston, TX, USA
4. Tsinghua Space Center and the Beijing National Research Center for Information Science and Technology, Tsinghua University, Beijing, China
5. College of Information Engineering, Shaoyang University, Shaoyang, China
6. Beijing Key Lab of Transportation Data Analysis and Mining, School of Computer and Information Technology, Beijing Jiaotong University, Beijing, China