Designed for a single-semester course, this concise and approachable text covers all of the essential concepts needed to understand modern communications systems. Balancing theory with practical implementation, it presents key ideas as a chain of functions for a transmitter and receiver, covering topics such as amplification, up- and down-conversion, modulation, dispersive channel compensation, error-correcting codes, acquisition, multiple-antenna and multiple-input multiple-output antenna techniques, and higher level communications functions. Analog modulations are also presented, and all of the basic and advanced mathematics, statistics, and Fourier theory needed to understand the concepts covered is included. Supported online with PowerPoint slides, a solutions manual, and additional MATLAB-based simulation problems, it is ideal for a first course in communications for senior undergraduate and graduate students.