This is the latest edition of the landmark communications systems textbook by one of electrical engineering's most prolific educators, B.P. Lathi, and co-author Zhi Ding. The Fifth Edition features over 200 fully worked-through examples incorporating current technology, an expansive amount of illustrations throughout the book, MATLAB codes throughout, and a full review of key signals and systems concepts. As digital communication technology has become important part of daily life, enrollment in courses on communications engineering has increased. Communications systems courses are now one of the most popular upper-level EE offerings because of intense student interest in the topic. In the new edition, Drs. Lathi and Ding have updated the book's examples to reflect current technology and including more MATLAB coding where appropriate.