1. School of Information Science and Engineering, Yanshan University, Qinhuangdao, Hebei Province, PR China
2. Hebei Key Laboratory of Information Transmission and Signal Processing, Yanshan University, Qinhuangdao, PR China
3. Key Laboratory of Measurement Technology and Instrumentation of Hebei Province, Yanshan University, Qinhuangdao, Hebei Province, PR China