PREFACE

This text is intended for use in a first course on digital signal processing (DSP), typically in senior or first-year graduate level. It may also be useful to engineers and scientists who use digital computers to process measured data. Some elementary knowledge on signals and systems is helpful but is not necessary. An attempt has been made to make this text as self-contained as possible.

As an introductory text, we discuss only two major topics: computer computation of frequency contents of signals and design of digital filters. These two topics follow logically a basic text or course on Signals and Systems, which now often covers both continuous-time (CT) and discrete-time (DT) cases. To be self-contained, we start from scratch. Chapter 1 introduces CT signals, DT signals, and digital signals. We discuss why CT signals are now widely processed digitally and how they are converted into digital signals. We also discuss why we study in this text, as in every other DSP text, only CT and DT signals even though digital signals are the signals processed on digital computers. In Chapter 2, we first discuss the frequency of CT and DT sinusoidal signals.We then introduce CT and DT Fourier series (frequency components) for periodic signals and establish their relationships. We then use the fast Fourier transform (FFT) to compute their frequency components.