Rongdan Zeng1, Yaosheng Lu1, Shun Long2, Chuan Wang1, Jieyun Bai3. 1. Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou, China. 2. Department of Computer Science, College of Information Science and Technology, Jinan University, Guangzhou, China. 3. Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou, China. Electronic address: bai_jieyun@126.com.