Introduction to Digital Communications, written especially for upper-level undergraduate courses, explores the basic principles in the analysis and design of digital communication systems, including design objectives, constraints and trade-offs. After portraying the big picture and laying the background material, this book lucidly progresses to a comprehensive and detailed discussion of all critical elements and key functions in digital communications. The second edition has been fully revised, with timely new chapters on wireless enabling systems and encryption, more practical examples, more application-focused real-world end of chapter exercises, and a more crisp and concise approach to the content.