Abstract:A concatenated code model is proposed for high-order Low-Density Parity-Check (LDPC) coded- modulation scheme. This model is comprised of a serial concatenation of an outer LDPC encoder, an inner Binary-Decimal Conversion (BDC) encoder and a puncture device. A joint parity-check matrix is derived for the concatenated code, and the corresponding joint demodulation and decoding algorithm, named Concatenated-Code Belief Propagation (CCBP), is presented. Simulation results show that this LDPC coded modulation scheme with the CCBP algorithm provides effective improvements relative to the Bit Interleaved Coded Modulation (BICM) scheme for high-order modulations.