A new labeling search method for bit-interleaved coded modulation with iterative decoding

The strategy for assigning binary indices to signal points is crucial to the performance of bit-interleaved coded modulation with iterative decoding (BICM-ID). We address the problem of finding the most suitable symbol mappings considering both the convergence behavior at low signal-to-noise ratios (SNR) and the bit error rate (BER) at high SNR. A new method based on the binary switching algorithm combined with the extrinsic information transfer chart (EXIT chart) is proposed, and we find some mappings exhibiting turbo cliff positions and bit error floors as desired.