Electrónica y Telecomunicaciones

The renowned communication theorist Robert Gallager brings his lucid writing style to this-year graduate textbook on the fundamental system aspects of digital communication. With the clarity and insight that have characterized his teaching and earlier textbooks, he develops a simple framework and then combines this with careful proofs to help the reader understand modern systems and simplified models in an intuitive yet precise way. Although many features of various modern digital communication systems are discussed, the focus is always on principles explained using a hierarchy of simple models. A major simplifying principle of digital communication is to separate source coding and channel coding by a standard binary interface. Data compression, i.e., source coding, is then treated as the conversion of arbitrary communication sources into binary data streams. Similarly, digital modulation, i.e., channel coding, becomes the conversion of binary data into waveforms suitable for transmission over communication channels. These waveforms are viewed as vectors in signal space, modeled mathematically as Hilbert space. A self-contained introduction to random processes is used to model the noise and interference in communication channels. The principles of detection and decoding are then developed to extract transmitted data from noisy received waveforms. An introduction to coding and coded modulation then leads to Shannon's noisy-channel coding theorem. The final topic is wireless communication. After developing models to explain various aspects of fading, there is a case study of cellular CDMA communication which illustrates the major principles of digital communication.