The fourth Edition emphasizes a concentrated revision of Parts III & IV (leaving Part I virtually intact). The later sections show greater elaboration of the basic concepts of stochastic processes, typical sequences of random variables, and a greater emphasis on realistic methods of spectral estimation and analysis. There are problems, exercises, and applications throughout. Aimed at senior/graduate students in electrical engineering, math, and physics departments.
RIP Prof. Papoulis. Some of the end of chapter problems can make the readers feel dumb and will certainly teach them a lot. The book hardly has any unnecessary words. Very efficiently/concisely written.