1. School of Information and Software Engineering, University of Electronic Science and Technology of China, Chengdu, China
2. School of Electronic Information and Electrical Engineering and Key Laboratory of Pattern Recognition and Intelligent Information Processing of Sichuan, Chengdu University, Chengdu, China
3. Key Laboratory of Electronic Information of State Ethnic Affairs Commission, College of Electrical Engineering, Southwest Minzu University, Chengdu, China
4. School of Mathematical Science, University of Electronic Science and Technology of China, Chengdu, China
5. College of Electronics and Information Engineering, Sichuan University, Chengdu, China