“Doped Fountain Code Decoding”

Abstract

We analyze the benefits of doping employed with belief-propagation decoding for increasing the throughput of fountain encoded symbol (packet) transmissions. The proposed doping mechanism selects doping symbols randomly from the set of input symbols contributing to degree-two output symbols. We study the doped belief propagation decoding for a fountain code with symbols drawn from an Ideal Soliton distribution. We show that the decoding process is a renewal process whereas the process starts all over afresh after each doping. The approximate interdoping process analysis revolves around a random walk model for the ripple size. This model furnishes a prediction on the number of required doping symbols and, furthermore, the throughput cost analysis of an enabling feedback scheme. We also find that the Ideal Soliton significantly outperforms the Robust Soliton distribution. We also illustrate how the proposed mechanism enables efficient random data collection with distributed storage in circular wireless networks.

Bio

Predrag Spasojevic received the Diploma of Engineering degree from the School of Electrical Engineering, University of Sarajevo, in 1990; and M.S. and Ph.D. degrees in electrical engineering from Texas A&M University, College Station, Texas, in 1992 and 1999, respectively. 

From 2000 to 2001, he was with WINLAB, Electrical and Computer Engineering Department, Rutgers University, Piscataway, NJ, as a Lucent Postdoctoral Fellow. He is currently an Associate Professor in the Department of Electrical and Computer Engineering, Rutgers University. His research interests are in the general areas of communication and information theory, and signal processing.

Dr. Spasojevic was an Associate Editor of the IEEE Communications Letters from 2002 to 2004 and served as a co-chair of the DIMACS Princeton-Rutgers Seminar Series in Information Sciences and Systems 2003-2004. He is currently Publications Editor of IEEE Transactions of Information Theory.