1. School of Communications and Information Engineering, Chongqing University of Posts and Telecommunications, Chongqing, China
2. School of Flexible Electronics (SoFE) and the State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou, Guangdong, China
3. Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education, Fujian Normal University, Fuzhou, China
4. College of Computer Science, Chongqing University, Chongqing, China
5. Laboratory for Information and Decision Systems, Massachusetts Institute of Technology, Cambridge, MA, USA