T. G. Tsuei is with the Department of Electrical Engineering, Ta Hwa Institute of Technology, Hsinchu, Taiwan, ROC, Han-Chieh Chao is a foil professor in the Department of Electrical Engineering, National Dong Hwa University, Hualien, Taiwan, ROC and Chih-Hung Ying is currently with Chunghwa Telecommunication Laboratories as a associate researcher, Chung li, Taiwan, ROC. Ta Hwa Institute of Tec...