1. Department of Information and Communication Engineering, Graduate Institute of Aeronautics, Chaoyang University of Technology, Taichung 413310, Taiwan
2. Department of Electrical Engineering, Tunghai University, Taichung 407224, Taiwan
3. Graduate Institute of Aeronautics, Chaoyang University of Technology, Taichung 413310, Taiwan
4. Department of Electronic Engineering, Cheng Shiu University, Kaoshiung 83347, Taiwan
5. Department of Electronic Engineering, Feng Chia University, Taichung 407102, Taiwan