Iterative (`Turbo') Algorithms on Factor Graphs: Theory and Applications

Originally developed for decoding turbo codes, normal factor graphs are a natural setting for the description of iterative techniques for detecting coded signals transmitted on a variety of channels. In addition, they provide a unified framework allowing one to understand the connections among seemingly different detection problems. This tutorial describes the application of normal factor graphs to a number of these problems, such as equalization of coded signals, multi-user detection, decoding of multilevel coded modulation, and reception of space--time coded signals.