Research on Raptor Codes with Unequal Error Protection Property

This paper proposes a new scheme to construct Raptor codes that can provide unequal error protection (UEP) property. It utilizes joint optimization of UEP-LDPC codes and UEP-LT codes to improve the performance of more important bits (MIB). The density evolution (DE) formulas over binary erasure channels (BEC) are derived. By using the DE formulas, the constructed UEP-Raptor codes are optimized. Simulation results show that, compared with the previous UEP-Raptor codes, the proposed UEP-Raptor codes can get better performances of both MIB and less important bits (LIB).