First and foremost, I extend my deepest thanks to my supervisor, Professor Dusit Niyato. From my perspective, he exemplifies the ideal doctoral advisor, combining the roles of a mentor, guide, and friend with his unwavering commitment, genuine passion for research, steadfast support, and selfless mentorship. His consistent dedication to his students' best interests has greatly motivated my pursuit of research excellence and desire to contribute to the scientific community.I am indebted to my Thesis Advisory Committee, Prof. Soong Boon Hee and Prof.Rui Tan, for their invaluable guidance, insightful critiques, and encouragement throughout my doctoral journey. My heartfelt thanks go to all my collaborators who have contributed immensely to my research and growth: Prof. Abbas