1. Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, China
2. State Key Laboratory of Internet of Things for Smart City, University of Macau, Macau, China
3. School of Electronic Engineering and Computer Science, Queen Mary University of London, London, U.K.
4. Department of Electrical Engineering, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany
5. Department of Electrical Engineering & Computer Science, Center for Pervasive Communications & Computing, University of California Irvine, Irvine, CA, USA