Diversified SLT codes based on feedback for communication over wireless networks

Fountain codes, such as LT (Luby transform) codes have been practical techniques for communication over wireless networks. RSD (Robust Soliton degree Distribution) is a key component of LT codes. However, LT codes do not make use of feedback. SLT (Shifted LT) codes have shown benefit by shifting RSD based on the number of recovered input symbols. However, degree values are limited to a small set. In this paper, DSLT (Diversified SLT) codes with a new degree distribution are proposed to explore the full potential of feedback. DSLT codes modify the RSD of LT codes in a different manner. They diversify the value of degree compared with SLT codes. Furthermore, hybrid SLT/DSLT codes were proposed to address the problem that most input symbols are recovered at the ending. We show both analytically and through real experiments, that DSLT codes have better performance in term of communication complexity and memory usage compared with SLT codes. © 2013 IEEE.