Improved shifted robust soliton distribution

Abstract

In shifted Luby transform (SLT) codes, robust soltion distribution (RSD) degree distribution was conducted with shifted rounding to derive shifted RSD (SRSD) degree distribution based on partial information. In shifted rounding process, the large shift of corresponding probability distribution destroyed belief propagation decoding rule, so the decoding symbols increased. Meanwhile, the overlarge probability distribution value of degree k resulted in the increase of decoding symbols. In this work, traditional SRSD degree distribution was developed to improved SRSD (I-SRSD) degree distribution function by decreasing degree shift of rounding and limiting probability distribution of degree k. Theoretical analysis and experimental results show that SLT codes by I-SRSD degree distribution can decrease decoding symbols as well as encoding and decoding complexity.