Bit-interleaved coded modulation with iterative decoding and 8 PSK signaling

TLDR

BICM‑ID offers a small free Euclidean distance yet a large diversity order thanks to bit interleaving, unlike trellis coded modulation. The study aims to address key design issues to improve decoding performance and derive analytical bounds under an ideal feedback assumption. The authors employ iterative decoding with soft bit decisions and extensive simulations to analyze BICM‑ID, enhancing intersignal Euclidean distance and exploring convergence to error‑free feedback performance. BICM‑ID delivers bandwidth‑efficient transmission with a large coding gain comparable to turbo TCM over Gaussian and Rayleigh fading channels, achieving near error‑free performance at high SNRs with lower complexity.

Abstract

We have suggested bit-interleaved coded modulation with soft decision iterative decoding (BICM-ID) for bandwidth-efficient transmission over Gaussian and fading channels. Unlike trellis coded modulation, BICM-ID has a small free Euclidean distance but large diversity order due to bit interleaving. With iterative decoding, soft bit decisions can be employed to significantly improve the conditional intersignal Euclidean distance. This leads to a large coding gain, comparable to that of turbo TCM, over both Gaussian and Rayleigh fading channels with much less system complexity. We address critical design issues to enhance the decoding performance and provide the analytical bounds on the performance with an ideal feedback assumption. We investigate the performance characteristics of BICM-ID through extensive simulations and show that at high signal to noise ratios, the performance of BICM-ID converges to the performance assuming error-free feedback.