Comparison of convolutional coupled codes and partially systematic turbo codes for medium code lengths

Ingmar Land Information and Coding Theory Lab University of Kiel, Germany e-mail: il@tf.uni-kiel.de http://www.tf.uni-kiel.de/ict Slim Chaoui Institute for Communications Technology Darmstadt University of Technology, Germany e-mail: slim@nesi.tu-darmstadt.de http://www.nesi.e-technik.tu-darmstadt.de Abstract | Two classes of concatenated codes of rate 1/2 and medium code lengths (600, 2000) are considered: convolutional coupled codes and partially systematic turbo codes. As opposed to the classical turbo code (Berrou, Glavieux), which is a systematic code, coupled codes contain no systematic bits and partially systematic turbo codes only some systematic bits. These codes can still be iteratively decoded and they show even better distance properties. This leads to better error rate performances in a wide range of signal-to-noise ratios, especially in the “flattening region”. The two code classes and their performances are presented and compared.