Distributed LT Codes with Unequal Error Protection

In this paper, we present a method to provide unequal error protection (UEP) for distributed sources in a two-source single-sink relay network scenario. A simple yet efficient technique to decompose the Robust Soliton Distribution (RSD) into two entirely different distributions by utilizing the concept of deconvolution is presented and these two different distributions are used at two different sources to encode their message symbols. The encoded symbols received at the relay are selectively XORed using appropriate relay rule and are forwarded to the sink making sure that the received symbols at the sink follow the RSD. We show that when these two sources use appropriately chosen different distributions for encoding, it is possible to provide unequal error protection to the sources. Keywords— Distributed LT codes, Fountain codes, LT codes, Robust soliton distribution (RSD), Unequal Error Protection.