Wittawat KositwattanarerkMahidol UniversityCommission on Higher Education2019-08-232019-08-232018-12-01Designs, Codes, and Cryptography. Vol.86, No.12 (2018), 2791-280515737586092510222-s2.0-85044380173https://repository.li.mahidol.ac.th/handle/123456789/45539© 2018, Springer Science+Business Media, LLC, part of Springer Nature. Iterative decoding and linear programming decoding are guaranteed to converge to the maximum-likelihood codeword when the underlying Tanner graph is cycle-free. Therefore, cycles are usually seen as the culprit of low-density parity-check codes. In this paper, we argue in the context of graph cover pseudocodeword that, for a code that permits a cycle-free Tanner graph, cycles have no effect on error performance as long as they are a part of redundant rows. Specifically, we characterize all parity-check matrices that are pseudocodeword-free for such class of codes.Mahidol UniversityComputer ScienceMathematicsArticleSCOPUS10.1007/s10623-018-0476-3