Turbo coding principles have found widespread applications in information theory and, in part, have entered into mainstream telecommunication theory and practice. These principles are used in error control, detection, interference suppression, equalization, and other communications-related areas. Turbo Codes: Principles and Applications is intended for use by advanced level students and professional engineers involved in coding and telecommunication research. The material is organized into a coherent framework, starting with basic concepts of block and convolutional coding, and gradually increasing in a logical and progressive manner to more advanced material, including applications. All algorithms are fully described and supported by examples, and evaluations of their performance are carried out both analytically and by simulations. The book includes new and original material on a bidirectional SOVA decoding algorithm, design of turbo codes based on the distance spectrum, design of code-matched interleavers, performance on fading channels, and a turbo trellis code modulation scheme. Trellis-based and iterative decoding algorithms, along with a comparison of algorithms based on their performance and complexity, are discussed. Various practical aspects of turbo coding, such as interleaver design, turbo codes on fading channels, and turbo trellis-coded modulation, are presented. Turbo Codes: Principles and Applications will be especially useful to practicing communications engineers, researchers, and advanced level students who are designing turbo coding systems, including encoder/decoder and interleavers, and carrying out performance analysis and sensitivity studies.