The second edition of Signals and Systems is a reorganization of the first edition, with the addition of some new material. The revisions serve to amplify those sections that experience has shown needed strengthening and clarification, thereby providing a more coordinated presentation of the text material. In this second edition, we retain the essential philosophy and content of the first edition—first with a study of con¬tinuous time systems, then with considerations of discrete time systems, and finally with a number of special areas that involve both continuous time and discrete time features.The opportunities for the use of the digital computer in this study are extensive. Many of the chapter problems are suitable for computer-aided study. Additionally, a number of specific computer experiments are included in most chapters. The use of the computer with this book is left to the discretion of the instructor.Solutions to all problems and computer experiments are contained in a separate Solutions Manual. In addition, computer program code is provided for the computer experiments; this can be distributed to students at their instructor’s discretion.