1. School of Information and Communications Engineering, Xi'an Jiaotong University, Xi'an, China
2. School of Electronics and Information Technology (School of Microelectronics) and Guangdong Provincial Key Labratory of Optoelectronic Information Processing Chips and Systems, Sun Yat-sen University, Guangzhou, China
3. School of Electronic and Information Engineering, Anhui University, Hefei, China
4. Department of Electrical and Computer Engineering, Concordia University, Montreal, QC, Canada