Cognitive radio is a form of wireless communication in which a transceiver can intelligently detect which communication channels are in use and instantly move into vacant channels while avoiding occupied ones. Providing an in-depth treatment of the core enablers of cognitive radio technology, this unique book places emphasis on critical areas that have not been sufficiently covered in existing literature. Professionals find expert guidance in the key enablers with respect to communications and signal processing. The book presents fundamentals, basic solutions, detailed discussions of important enabler issues, and advanced algorithms to save engineers time with their projects in the field. For the first time in any book, practitioners find an adequately detailed treatment of spectrum sensing that covers nearly every aspect of the subject.