Nahvi-80709 book December 13, 2012 16:23
xviii Preface
Introducing the tools and applying them separately simplifies the structure of the course.
Another advantage of the present organization is that the analyses of signals and systems
in the continuous- and discrete-time domains can stand on their own (both conceptually
and in terms of analysis tools). Each domain may be taught without requiring the other.
Thus, for programs that are designed to offer a DSP course, the discrete-time part of the
book will satisfy the prerequisites of such a course.
Each part begins with the introduction of signals and their models in the time do-
main. It then defines systems, linearity, and time invariance, along with examples. Time-
domain solution methods, such as convolution and differential/difference equations, are
presented next, followed by the transform domains. These are brought together in cap-
stone chapters on the system function and frequency response. Chapter 10 on sampling
provides a bridge between the continuous- and discrete-time domains.
Each chapter is made of sections and no subsections. Each section addresses a
single discussion item, starting with the introduction of a topic, mathematical tools
used to address that topic, the application of those tools, and one or two examples. To
a large extent, therefore, each section is a learning unit and can provide the student
with a concluding marker in learning the subject. In that sense the sections are modular
and convenient for instruction. The modular organization of the book provides a direct
approach and an effective tool for learning the fundamentals of signals and systems. As
avehicle for lectures, 5 to 10 essential sections may be covered in an hour, while others
may be assigned as outside reading or homework.
Reference to other sections, figures, formulas, and other chapters is kept to a min-
imum. This provides easy and direct access to material, a feature much preferred by
students and instructors. The modular structure of the chapters and sections also makes
the book a convenient tool for instructional needs in a wide range of teaching scenarios
at various levels of complexity.
Illustrative examples, end-of-chapter problems, and supplementary problems with
solutions comprise other important components of the book. The book contains a total
of nearly 475 examples, 175 problems with solutions, and 750 end-of-chapter problems.
The examples and problems are of two types: (1) mathematical analyses and exercises
that represent abstractions of engineering subjects and (2) contextual problems, such
as those seen in electric circuits and devices, communication, and control. For the EE
and CPE student these subjects provide a context to convey and develop fundamental
concepts in signals and systems.
Examples from familiar signals and tangible systems in engineering can illustrate the
utility of the relevant mathematical analysis. They can make the subject more attractive
and generate motivation. In accordance with the above pedagogy, the book assumes
that the reader is familiar with the operation of basic circuits and devices (such as
passive RLC circuits and active circuits including dependent sources and operational
amplifier models) and uses these to illustrate and reinforce the mathematical concepts.
It also assumes familiarity with elementary trigonometric functions, complex numbers,
differentiation/integration, and matrices. The Appendix at the end of the book can be
used to refresh the reader’s memory on electric circuits.