Introducing the fundamentals of digital communication with a robust bottom-up approach, this textbook is designed to equip senior undergraduate and graduate students in communications engineering with the core skills they need to assess, compare, and design state-of-the-art digital communication systems. Delivering a fast, concise grounding in key algorithms, concepts, and mathematical principles, this textbook provides all the mathematical tools for understanding state-of-the-art digital communications. The authors prioritise readability and accessibility, to quickly get students up to speed on key topics in digital communication, and includes all relevant derivations. Presenting over 70 carefully designed multi-part end-of-chapter problems with over 360 individual questions, this textbook gauges student understanding and translates knowledge to real-world problem solving. Accompanied online by interactive visualizations of signals, downloadable Matlab code, and solutions for instructors.