computer technology

I found this book to be an excellent fundamental text about DSP. But is it a good introductory book for beginners? Well, it depends... The book covers the essential topics in great depth and that means every one of its 800+ pages is packed with concepts and details and examples. The style is clear, but the amount of information can be a little overwhelming when you read it for the first time. If you have time, patience, a good maths background, the desire to master the subject, and someone to clarify your doubts, this can be the best first book on DSP you could ever buy. If you just want to learn the basics, and don't have much time or patience you should probably look elsewhere.

I am referring here to the Digital Signal Processing (DSP) that the authors wrote in the 1970's or earlier versus the more recent editions of Discrete-Time Signal Processing (DTSP).

I have both the DSP version and the 1st edition of DTSP, and used them for coursework. From my personal recollection: I tried to take an introductory graduate-level DSP course twice, once with the old DSP text (but did not get to finish), and the second time completing the course from another college with the DTSP text. DSP, in spite of its introductory and pioneering nature, turned out to be the more readable and better organized textbook among the two. It is shorter by many pages, less verbose, less "heavy and circular in arguments", and quicker to come to the point, not to mention being clearer, more lucid, and well-illustrated with good examples and diagrams without overwhelming the reader. The beginning chapters are well written with introduction to the applications of Complex Variables in the context of DSP as an EE subject. In short, DSP by Oppenheim and Schafer is the less ambitious book of the two, but really accomplishes much more by doing less and focusing on the essential concepts underlying DSP.

I can see why and where many beginning EE Signal Processing students tend to get frustrated. DTSP, 1st edition, is actually a rewritten version of DSP, albeit meant to be a major extension (or expansion, if you wish) with more applications appended and "heavier expositions". (This reminds me of many other books by MIT EE faculty on the market.) I find the most frustrating part of DTSP is the chapters on transcending from the Discrete Fourier Transform (DFT) to Fast Fourier Transform (FFT). Why? All you have to do is look at the way the authors present the DFT, then get to understand the truncated DFT, and try to follow the steps that supposedly get one toward FFT's - not at all clear or well-connected conceptually. It is even more obvious when one tries to do the moderately difficult and somewhat tedious exercises at the back of each chapter. While it is true that DTSP appears superficially "precise and rigorous", I find it a bit convoluted and too ambitious in its treatment of digital signal processing topics, indicative of a desire to reflect trappings of the latest applications by demonstrating the power of the theory presented. Why not just return to the fundamentals of DSP and limit the topics to a manageable level, thereby retaining a high degree of visibility for the more average EE student. (Maybe DTSP was meant to be taught by the authors themselves, or by their Ph.D. students. That way, the obscure points, discussions and topics in the textbook could be explained away in live classroom lectures via student interactions. Right?) In spite of all this, I think DTSP has intrinsic value in EE Signal Processing, being that it retained much of the key concepts in the older DSP text with some original flavor.

Suggestion to authors: Write another book on DSP, but limit the book to concepts and some elementary applications, just like the 1970's original, or better still edit and update the original to be published as an inexpensive classic by, say, Dover. Rewrite DTSP as the follow-on textbook. How about it? I really miss the lucid style of the more original DSP textbook by the authors. And I mean it, seriously!

This book seems to follow the disappointing (to me at least) model of many engineering texts--that being the reluctance to present new mathematical concepts/techniques. Almost every mathematical concept/technique used in this book was already covered by the prerequisite text by Oppenheim, "Signals and Systems." It would seem that a subject so entrenched with complex numbers and polynomials could be taught in such a manner that would include theorems and concepts from these well-established mathematical disciplines. Note that I did not read the chapter on Hilbert transforms, or the section on the Discrete Cosine Transform, so I cannot comment on them. I did read all other sections. The sections on random signals do introduce new concepts, but they were only put in as a quick review of concepts meant to be studied in a random processes class. On the other hand, this is a very readable book, which has proven very useful. It does present MANY new engineering concepts. If analytic function theory had been introduced, this book probably would not have room left to be as complete a reference for existing introductory DSP theory. However by avoiding the math it has limited the continuing students ability to develop insight into deeper theory, or develop new theory.