Information Theory and Reliable Communication

Rating:
Summary: Masterpiece. There is a reason this book is a classic.
Review: Much like Wozencraft and Jacobs book (Principles of communication engineering... which blows away the best textboks of today by Sklar and Proakis), this book was written in traditional style. Gallager's masterpiece was written in the golden era prior to the unfortunate "new math" revolution which occured in the late 1970's. Today's "dumbed-down" textbooks (math books, engineering books, etc...) are often referred to as recipe books because they often have 4 - 6 revisions in just a few years. Todays books tell you how to build and design things such as good codes for certain applications, but they neglect to give you the very deep theoretical underpinnings upon which these things are based. How are students and future researchers supposed to become the next generation of designers of codes and such.... if they aren't actually taught the deep theory behind their design. Books today only teach you how to implement them.

Aside from the intense mathematical rigour devoted by Gallager to this textbook, which blows away Cover and Thomas' "Elements of Information Theory".... the primary difference between the two books is that the focus here is on channel code design, whereas Cover and Thomas focus more on source coding because that is their field of expertise. Even still, Gallagers treatment of the theoretical underpinnings of source coding is alot more rigorous. Cover only glances over the theory... and quite frankly, I think those guys are just terrible writers, but they do get more into the practical implementation as it pertains to more modern applications.

In summary, much like Wozencraft and Jacobs... there is a reason that this book never needed a second edition... because it's so rigorous, that 37 years later..... theres just no need for an update!!! Gallager would be better of just writing another book (which he has)...

Rating:
Summary: Masterpiece. There is a reason this book is a classic.
Review: Much like Wozencraft and Jacobs book (Principles of communication engineering... which blows away the best textboks of today by Sklar and Proakis), this book was written in traditional style. Gallager's masterpiece was written in the golden era prior to the unfortunate "new math" revolution which occured in the late 1970's. Today's "dumbed-down" textbooks (math books, engineering books, etc...) are often referred to as recipe books because they often have 4 - 6 revisions in just a few years. Todays books tell you how to build and design things such as good codes for certain applications, but they neglect to give you the very deep theoretical underpinnings upon which these things are based. How are students and future researchers supposed to become the next generation of designers of codes and such.... if they aren't actually taught the deep theory behind their design. Books today only teach you how to implement them.

Aside from the intense mathematical rigour devoted by Gallager to this textbook, which blows away Cover and Thomas' "Elements of Information Theory".... the primary difference between the two books is that the focus here is on channel code design, whereas Cover and Thomas focus more on source coding because that is their field of expertise. Even still, Gallagers treatment of the theoretical underpinnings of source coding is alot more rigorous. Cover only glances over the theory... and quite frankly, I think those guys are just terrible writers, but they do get more into the practical implementation as it pertains to more modern applications.

In summary, much like Wozencraft and Jacobs... there is a reason that this book never needed a second edition... because it's so rigorous, that 37 years later..... theres just no need for an update!!! Gallager would be better of just writing another book (which he has)...

Rating:
Summary: Good Introductory Material for information theory
Review: This book on information theory, written in the classic Gallager style, clear, lucid and simple, is good material for a person who requires an introduction to Information theory. It requires a working knowledge of probability theory. Once this criterion is satisfied, this book is easy to understand, and is quite "informative" too!

Rating:
Summary: A true classic
Review: This is a definitive text written by quite possibly the greatest information theorist this country has produced, next to Claude Shannon. The author is personally responsible for some of the most central results in the field for the last forty years.

Gallager's book was the standard text in the field for much of the time it has been in print. In recent years, other textbooks, most notably the one by Cover and Thomas, have become more widely used in introductory classes in information theory. There may be several reasons for this. One may be the relative lack of motivating material in Gallager's text. The author assumes the reader is already convinced of the importance of the problems to be treated in the book. Cover's book, on the other hand, has greater appeal to the general scientist/engineer interested in the fascinating connections between information theory and various other areas of human inquiry. A second reason may be the relatively high level of intellectual rigor required of the reader. Gallager is a brilliant theorist, and his precision and meticulousness are apparent in the pages. The casual undergraduate or general reader may find some of the analysis intimidating and abstruse (although if he reads carefully, the reader always finds plenty of physical intuition to support theoretical arguments). A final reason is that some of the material (although certainly not the most important ones) in the book has become dated, and many exciting new developments in information theory, such as multi-user channels, simply never had a chance to make it in.

The above qualifications, however, should in no way obscure the greatness of the book. For anyone who is serious about information theory, this book is INDISPENSABLE. The relatively lack of breadth is more than made up for by the depth of the treatment. The precision that may intimidate an undergraduate is a godsend for a researcher frustrated with the sloppiness that occurs occasionally (or quite often) in other texts. And while the book may miss some new developments, its treatment of classic Shannon theory, particularly the noisy channel coding theorem, is unparalleled in its elegance and power. Moreover, the book is often the only recourse the researcher has when troubled with the subtleties of mind-numbing issues such as the continuous-time Gaussian channel. Finally, almost every one of the exercises in the book is a gem. There are any number of papers in information theory which cite Gallager's exercises as proofs!

The only true regret the reviewer has regarding the book is that Gallager has not written a new edition.