Book Review

Codes for Mass Data Storage Systems
          Fully Revised Second Edition!
by Kees A. Schouhamer Immink
Institute for Experimental Mathematics, Essen-Duisburg, Germany

This book, much like its predecessor, is an excellent exposition on the exciting field of constrained coding for storage applications. It iscomprehensive in that almost every area within the purview of constrained coding can be found within: capacity computation, spectral analysis, design, encoding, and decoding of run-length limited (RLL), DC-free, and DC-RLL codes. The required mathematical background is minimal beyond a basic knowledge of probability, linear algebra, and some combinatorics.

Kees Immink is a pioneering researcher in the field of constrained coding and this is thoroughly reflected in the profound and lucid treatment of the subject in this book.

The book and its chapters are very well-structured; it begins by describing techniques used to analyze constrained codes and continues with chapters on RLL codes, DC-free codes, and DC-RLL codes. These codes are described in considerable detail in terms of their design, performance, and implementation. The text is illustrated with many figures and tables, and each chapter contains numerous examples all of which serve to clarify and firmly embed the concepts in the reader's mind.

Although rich in theoretical aspects of constrained codes, the book is written more with the practitioner, rather than the researcher, in mind. Wherever possible, the author has traded mathematical rigor for brevity, no doubt to make the book accessible to as wide an audience as possible. However, adequate references are provided for the reader who wants to delve deeper. The list of over 350 references, including journal and conference publications as well as patents, is very extensive and a result of the author’s years of research in the field. The author provides in-depth description of codes, like the EFM code and several RLL codes, some of which have become standards in the storage industry.

The book is obviously an extension of the 1991 edition, but as the author notes it also covers significant developments of the past decade in the field of constrained coding. In keeping with their growing importance, sliding-block codes and enumerative coding are described in much more detail than in the previous edition. A section on enumeration using fixed-point arithmetic has been added, again as part of the author's effort to blend theory with practice. A new chapter on guided scrambling has been added and describes in considerable detail the application of the method for the design of DC-free codes. Numerous other additions to the new edition make it one of the most comprehensive texts on constrained coding. Although ertain new topics, e.g. two-dimensional RLL codes or (0,G/I) codes, areincluded in the book, they receive only a cursory mention which leaves the reader desiring more. Although the new edition expands on the old, some chapters that were present in the previous edition have been removed, without explanation. Again, however, adequate references are provided on these subjects pointing the inquisitive reader in the right direction.

The book is highly recommended for anyone who maintains a keen interest in storage systems, from those with little or no background in the field of constrained coding to engineers in the storage industry, for whom the book will serve as a handy reference.

Naveen Singla

Electronic Systems and Signals Research Laboratory,
Department of Electrical and Systems Engineering,
Washington University,
St. Louis, MO 63130, USA.
http://www.essrl.wustl.edu/~singla