ACKNOWLEDGEMENTS

First, I would like to acknowledge my advisor, Prof. Zhong He, for his patient guidance, inspiring suggestions and continuous support. It’s a great opportunity and a precious experience to join his group and learn knowledge from his brilliant mind. Especially, I want to thank him to give me the opportunity to go to the IEEE meeting every year, which is a really helpful way to expand my view of the academic society. I would like to thank my committee member, Prof. Ronald Fleming, Prof. Thomas Zurbuchen and Dr. Feng Zhang for their instructions and guidance during my PhD research. I would like to give my gratitude to my colleagues, Dr. Dan Xu, Dr. Stephe