Wang, Yi; Burr, Alister G. (Communications Research Group, Department of Electronics, University of York, UK)
We propose a novel space-time coded modulation approach for multi-antenna systems, namely space-time multilevel coded modulation with iterative decoding (ST-MLCM-ID), for the purpose of exploiting both multiplexing gain and multilevel coding gain. This scheme allows flexible selection of spacetime mappings, signal constellations, and outer codes used on each level of the mapping, for each antenna. We introduce the concept of the space-time distorted bit-level extrinsic information transfer (STDBL-EXIT) function, derive the area properties of the STDBL-EXIT functions in information theoretic terms, and show a highly-efficient code design rule for ST-MLCMID. Simulations further demonstrate that by employing our rule based on the STDBL-EXIT function, ST-MLCM-ID is capable of achieving full convergence close to the theoretical limit, while also allowing sufficient flexibility in the choice of codes on each level of the space-time mapping of each antenna.