Low-density parity-check coded modulation using multiple signal maps and symbol decoding

This paper introduces a multiple signal mapped LDPC-BICM that enhances performance by combining coding and modulation similar to trellis coded modulations. Furthermore, a symbol decoding of LDPC-BICM is introduced, which directly uses the symbol metric. With the symbol decoding, an LDPC-BICM system can take the advantage of non-Gray constellation mappings. Simulation results are presented to show that the mixed non-Gray and Gray mapped LDPC-BICM with symbol decoding outperforms the conventional single Gray mapped LDPC-BICM with bit decoding by at least 0.2 dB.