This research would not have been possible without the support of several people and institutes who have supported and encouraged me to the completion of this dissertation. I could probably have written a full chapter to acknowledge those, who, in different ways, have supported me during my PhD life at Nanyang Technological University (NTU). First and foremost, my utmost gratitude to my supervisor, Assoc. Prof. Benjamin Premkumar who was abundantly helpful and offered me invaluable support and guidance during the lifetime of this research. I also wish to express my deepest gratitude toward Prof. G.V. Anand from the Indian Institute of Science without him this study would not have been successful. He has greatly contributed to this project and constantly advised me during the completion of my research. It was a great blessing for me to have the opportunity to work with him. I would also like to thank Assoc. Prof. C.T. Lau, my co-supervisor, who has provided me support and feedback whenever it was required. I would like to appreciate the Defense Science and Technology Agency (DSTA) of Singapore, the sponsor of this project for their support and their feedbacks throughout the project. I would also like to convey thanks to Agency for Science, Technology and Research of Singapore (A*Star) for granting me the scholarship to pursue my PhD at NTU and to strengthen my passion in research. I would also like to thank the staff and technicians in Centre for Multimedia and Network Technology (CeMNet) for the assistance and the facilities they provided me. My special thanks also to all my friends at CeMNet especially Hari, Ashish and Xionghu for creating a friendly environment and making my everyday research life a pleasant one. I have benefited a lot from different interesting discussions that we have had. Last but not the least, I wish to express my love and gratitude to my beloved family, for their endless love and support, throughout my studies and God, for giving me the strength, courage and hope to follow my dreams, no matter how hard or impossible they seem. i