This book grew out of our research, industry consulting and con­ tinuing education courses. Turbo coding initially seemed to belong to a restricted research area, while now has become a part of the mainstream telecommunication theory and practice. The turbo decoding principles have found widespread applications not only in error control, but in de­ tection, interference suppression and equalization. Intended for use by advanced students and professional engineers, involved in coding and telecommunication research, the book includes both basic and advanced material. The chapters are sequenced so that the knowledge is acquired in a logical and progres­ sive way. The algorithm descriptions and analysis are supported by examples throughout the book. Performance evaluations of the presented algorithms are carried out both analytically and by sim­ ulations. Basic material included in the book has been taught to students and practicing professionals over the last four years in the form of senior undergraduate or graduate courses, lecture series and short continuing education courses.