Bit-Labeling for Delayed BICM with Iterative Decoding

This paper is concerned with the delayed bit-interleaved coded modulation with iterative decoding (DBICM-ID). We present new criteria for bit-labeling in the DBICM-ID system based on the harmonic mean of the minimum squared Euclidean distance (HMMSED) and the mean average bit-wise mutual information (MABMI) criteria. Different from the conventional HMMSED criterion, taking into account the conditions varying from no feedback to perfect feedback, we also evaluate the variance of the harmonic mean, which is then deployed to reveal the convergence rate. We take 16-QAM as an example to confirm our analysis. Numerical results show that, DBICM-ID with the designed bit-labeling scheme can obtain an extra coding gain of about 0.5 dB.