The study of communication systems is basic to an undergraduate program in electrical engineering. In this third edition, the author has presented a study of classical communication theory in a logical and interesting manner. The material is illustrated with examples and computer-oriented experiments intended to help the reader develop an intuitive grasp of the theory under discussion. introduction representation of signals and systems continuous-wave modulation random processes noise in cw modulation systems pulse modulation baseband pulse transmission digital passband transmission spread-spectrum modulation fundamental limits in information theory error control coding advanced communication systems