02042oam 2200409zu 450 991087266580332120241212214858.0(CKB)111026746723916(SSID)ssj0000455033(PQKBManifestationID)12211793(PQKBTitleCode)TC0000455033(PQKBWorkID)10398888(PQKB)11441852(NjHacI)99111026746723916(EXLCZ)9911102674672391620160829d1998 uy engur|||||||||||txtccr1998 IEEE International Symposium on Information Theory[Place of publication not identified]IEEE19981 online resource (526 pages)Bibliographic Level Mode of Issuance: Monograph9780780350007 0780350006 It is now understood that the turbo decoding algorithm is an instance of a probability propagation algorithm (PPA) on a graph with many cycles. In this paper we investigate the behavior of an PPA in graphs with a single cycle such as the graph of a tail-biting code. First, we show that for strictly positive local kernels, the iterations of the PPA converge to a unique fixed point, (which was also observed by Anderson and Hladik (1998) and Weiss (1997)). Secondly, we shall generalize a result of McEliece and Rodemich (1995), by showing that if the hidden variables in the cycle are binary-valued, the PPA will always make an optimal decision. (This was also observed independently by Weiss). When the hidden variables can assume 3 or more values, the behavior of the PPA is much harder to characterize.Information theoryCongressesInformation theory003.54Institute of Electrical and Electronics Engineers, Inc. StaffPQKBPROCEEDING99108726658033211998 IEEE International Symposium on Information Theory2510307UNINA