UEP Online Fountain Codes with Sequential Window Strategy

Online fountain code with Unequal Error Protection (UEP) has been proposed to provide better protection for the More Important Symbols (MISs) than that of the Less Important Symbols (LISs). However, the greater priority for MISs is accomplished substantially through choosing MISs with higher probability than that of LISs in encoding. Compared with normal online fountain code, this requires more code symbols to recover all symbols, which leads to high overhead. To reduce the overhead without affecting UEP performance, we propose a novel UEP online fountain codes scheme with sequential window strategy to provide best protection for LISs after decoding MISs in the completion phase. We have theoretically analyzed the upper bound on the overhead of the proposed UEP scheme and evaluated the performance by simulation. Both results show that the proposed scheme has lower overhead than the UEP online fountain codes scheme in [1].