Elements of information theory
Elements of information theory
Information Theory and Reliable Communication
Information Theory and Reliable Communication
Bit-Interleaved Coded Modulation
Foundations and Trends in Communications and Information Theory
Bit-interleaved coded modulation
IEEE Transactions on Information Theory
Multilevel codes: theoretical concepts and practical design rules
IEEE Transactions on Information Theory
Mismatched decoding revisited: general alphabets, channels with memory, and the wide-band limit
IEEE Transactions on Information Theory
Trellis-coded modulation with bit interleaving and iterative decoding
IEEE Journal on Selected Areas in Communications
Bit-Interleaved Coded Modulation
Foundations and Trends in Communications and Information Theory
Performance analysis for BICM transmission over Gaussian mixture noise fading channels
IEEE Transactions on Communications
Hi-index | 754.84 |
We revisit the information-theoretic analysis of bit-interleaved coded modulation (BICM) by modeling the BICM decoder as a mismatched decoder. The mismatched decoding model is well defined for finite, yet arbitrary, block lengths, and naturally captures the channel memory among the bits belonging to the same symbol. We give two independent proofs of the achievability of the BICM capacity calculated by Caire et al., where BICM was modeled as a set of independent parallel binary-input channels whose output is the bitwise log-likelihood ratio. Our first achievability proof uses typical sequences, and shows that due to the random coding construction, the interleaver is not required. The second proof is based on the random coding error exponents with mismatched decoding, where the largest achievable rate is the generalized mutual information. Moreover, the generalized mutual information of the mismatched decoder coincides with the infinite-interleaver BICM capacity. We show that the error exponent--and hence the cutoff rate--of the BICM mismatched decoder is upper-bounded by that of coded modulation and may thus be lower than in the infinite-interleaved model; for binary reflected Gray mapping in Gaussian channels the loss in error exponent is small. We also consider the mutual information appearing in the analysis of iterative decoding of BICM with extrinsic information transfer (EXIT) charts: if the symbol metric has knowledge of the transmitted symbol, EXIT mutual information admits a representation as a pseudo-generalized mutual information, which is in general not achievable. A different symbol decoding metric, for which the extrinsic side information refers to the hypothesized symbol, induces a generalized mutual information lower than the coded modulation capacity. In this case, perfect extrinsic side information turns the mismatched-decoder error exponent into that of coded modulation.