This textbook, now in its 5th edition, provides updated state-of-the-art coverage of spread spectrum communication systems with new applications throughout. In this edition, the author extends sections with fleshed out detail on the topics and their advancements. The author also breaks down some of the more complex sections to make them easier to understand. In addition, new subsections, sections, figures, and problems will be included throughout. New topics include special direct-sequence systems optical and chaotic, channel-state information, massive MIMO, information theory and MIMO, network enhancements, Lagrange multipliers, and mathematical inequalities. As with previous edition, the author presents topics in a practical way that's of interest to both researchers and system designers. He includes updated problems at the end of each chapter, which are intended to assist readers in consolidating their knowledge and to provide practice in analytical techniques.