Belief propagation and turbo code: Information geometrical view
In this article, we describe the information geometrical understanding of the belief propagation decoder, especially of the turbo decoding. The turbo decoding was proposed by Berrou et al. early in 90’s, and many studies have been appeared on this practical and powerful error correcting code. Even though many experimental results support the potential of the turbo decoding, there is not sufficient theoretical analysis for the decoding method. We investigate the problem from information geometrical viewpoint. From the new viewpoint, we establish a new framework for analyzing the turbo code, and reveal basic properties.