A practical message-wise unequal error protection coding scheme

We propose a practical message-wise unequal error protection (UEP) scheme using low-density parity-check (LDPC) codes, where one or more special messages are more protected than other ordinary messages, which performs codeword flipping to separate the codewords of special and ordinary messages. To better distinguish the original and flipped codewords, the LDPC codes with all-odd degree check nodes are employed. The decoder performs message type detection and codeword flipping detection by tracking the number of unsatisfied check nodes in iterative decoding. We provide both finite-length and asymptotic performance analysis for the proposed coding scheme. Simulation results are provided to show that the proposed practical message-wise UEP schemes offer capacity-approaching protections to both types of messages as if only one type of message is transmitted.