This second edition contains much of the content of Linear Systems and Signals , Third Edition, by the same authors, with added chapters on analog and digital filters and digital signal processing, plus additional applications to communications and controls. Unlike Linear Systems & Signals 3e, in this book the Laplace transform follows Fourier. This book contains enough material on discrete-time systems to be used in a traditional course in Signals and Systems and in an introductory course in Digital Signal Processing.
Lathi's writing is extremely clear and, at times, funny. I loved some of the historical background he added, especially concerning Heaviside. He begins with a very helpful review of partial fraction expansion and linear algebra, two mathematical domains one needs to be facile in to absorb the remainder of the book. The book then covers a lot of ground. One could look at the book as divided into two major sections: I-Continuous-Time (Chapters 1-7) signals and systems, development of continuous Fourier/Laplace, sampling, analog filters (pole-zero placement, Butterworth, Chebyshev, etc.), and control systems. II-Discrete-Time (Chapters 8-13) Fourier, z-transform, digital filters, and space-state analysis). It's a wonderful resource for developing a mental throughline for the relationship between signals/systems, digital signal processing, and controls.