The authors would like to acknowledge their research collaborators for the joint research effort on many topics of mutual interest that helped the realization of this book. Special thanks go to Drs Weihua Zhuang, Mohamed Kashef, Mohamed Abdallah, Mohamed Marzban, Mohamed Khairy, Amila Gamage, Sherman Shen, Hafiz Yasar Lateef, Amr Mohamed, Mohamed-Slim Alouini, Hina Tabassum and Muhammad Ali Imran.

The authors would like to acknowledge the support from Qatar National Research Fund offered through NPRP.