1. Department of Electrical Engineering, National Ilan University, Yilan 26047, Taiwan
2. Chongqing Key Lab of Mobile Communications Technology, School of Communication and Information Engineering, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
3. School of Informatics, Xiamen University, Xiamen 361005, China
4. AME-GEOLOC, University Gustave Eiffel, F-44344 Bouguenais, France
5. ALGORITMI Research Centre, Universidade do Minho, 4800-058 Guimarães, Portugal