Braided Convolutional Codes – A Class of Spatially Coupled Turbo-Like Codes
Michael Lentmaier
Department of Electrical and Information Technology
Lund University, Lund, Sweden
Abstract:
We investigate the impact of spatial coupling on the thresholds of turbo-like codes. Parallel concatenated and serially concatenated convolutional codes as well as braided convolutional codes (BCCs) are compared by means of an exact density evolution (DE) analysis for the binary erasure channel (BEC). We propose two extensions of the original BCC ensemble to improve its threshold and demonstrate that their BP thresholds approach the maximum-a-posteriori (MAP) threshold of the uncoupled ensemble. A comparison of the different ensembles shows that parallel concatenated ensembles can be outperformed by both serially concatenated and BCC ensembles, although they have the best BP thresholds in the uncoupled case.
Biography:
Michael Lentmaier is an Associate Professor at the Department of Electrical and Information Technology at Lund University, which he joined in January 2013. His research interests include design and analysis of coding systems, graph based iterative algorithms and Bayesian methods applied to decoding, detection and estimation in communication systems. He serves as director of the masters program on wireless communications.
He received the Dipl.-Ing. degree in electrical engineering from University of Ulm, Germany in 1998, and the Ph.D. degree in telecommunication theory from Lund University, Sweden in 2003. He then worked as a Post-Doctoral Research Associate at University of Notre Dame, Indiana (with Prof. Daniel J. Costello), and at University of Ulm (with Prof. Martin Bossert). From 2005 to 2007 he was with the Institute of Communications and Navigation of the German Aerospace Center (DLR) in Oberpfaffenhofen, where he worked on signal processing techniques in satellite navigation receivers. From 2008 to 2012 he was a senior researcher and lecturer at the Vodafone Chair Mobile Communications Systems at TU Dresden and was heading the Algorithms and Coding research group.
Dr. Lentmaier received the best presentation award for his paper titled “Dynamic Multipath Estimation by Sequential Monte Carlo Methods” at the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007) and the IEEE Communications Society & Information Theory Society Joint Paper Award 2012 for his paper titled “Iterative Decoding Threshold Analysis for LDPC Convolutional Codes”. He is a senior member of the IEEE and served as an editor for IEEE Communications Letters from 2010 to 2013 and IEEE Transactions on Communications since 2014.