Bit mapping design for LDPC Coded BICM schemes with multi-edge type EXIT chart

In this letter, we consider the bit mapping (BM) design for regular low-density parity-check (LDPC) coded bit-interleaved coded modulation (BICM) schemes. We propose a check-node type distribution and develop multi-edge type extrinsic information transfer (EXIT) functions for the regular LDPC coded BICM schemes. Based on the EXIT functions, we propose a two-phase design method to generate the optimized practical BM in terms of the lowest decoding threshold for a given finite length LDPC code. Simulation results show that the proposed BM has a better decoding threshold compared with those of the existing works