This book provides a comprehensive tutorial to signal classification, an important signal processing technique that enables cognitive radios to identify the kind of users present in a frequency band, helping a radio to characterize the environment in which it is operating.  Engineers involved in the design and implementation of cognitive radio receivers will benefit from this book?s coverage of a newly developed, multiuser signal classification algorithm, as well as techniques for design of other components to work in conjunction with the signal classifier, such as blind equalizers, blind channel estimators, and cognitive engines.