Open AccessArticle by Jing Wang 1, Naike Du 1, Tiantian Yin 2, Rencheng Song 3, Kuiwen Xu 4, Sheng Sun 5 and Xiuzhu Ye 1,* 1 School of Information and Electronics Engineering, Beijing Institute of Technology, Beijing 100081, China 2 Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore 3 School of Instrument Science and Opto-Electronics Engineering, Hefei University of Technology, Hefei 230009, China 4 School of Information and...