Communications technology may come and go, but the ne Fifth Edition of Rodger Ziemer and William Tranter’s Principles of Communications: Systems, Modulation, and Noise equips you with basic principles of communications at the physical layer—principles that will keep you on the cutting edge, regardless of how the technology changes. Featuring thorough yet concise coverage, chapters gives you the necessary background in signal, system, probability, and random process theory required to understand the analog and digital communications topics covered in the book. You’ll also learn about such currently popular topics as cellular radio, spread spectrum, and orthogonal frequency-division multiplexing.