1. College of Medical Information Engineering, Zunyi Medical University, Guizhou 563006, China; College of Communication Engineering, Army Engineering University of PLA, Nanjing 210007, China
2. The Sixty-third Research Institute, National University of Defense Technology, Nanjing 210007, China
3. Department of Communication Engineering, Rocket Force University of Engineering, Xi'an 710025, China
4. College of Communication Engineering, Army Engineering University of PLA, Nanjing 210007, China