Abstract:

Degree distribution is key to the decoding efficiency of LT codes. With analysis of the variation of preprocessing set, this paper proposes the Optimal Degree Distribution (ODD) of LT codes and analyzes its drawbacks in realization. On the basis of ODD, a practical Suboptimal Degree Distribution (SODD) is put forward. Through testing, with respect to the mean value, the top value and variance of decoding efficiencies, LT codes with SODD perform better than that with Robust Soliton Degree Distribution. The conclusion of research is practically valuable in improving efficiencies of data distribution applications.

Key words: digital fountain, LT codes, suboptimal degree distribution, robust soliton degree distribution