Spectrally efficient MIMO transmission schemes based on multilevel codes

In this paper we compare different transmission schemes for multiple antenna transmission systems based on multilevel codes (MLC) in terms of the maximum rate that they can achieve. We introduce a new architecture that can provide nearly optimum performance without iterative demapping and has lower complexity than the full multi-level coding scheme. As opposed to BICM and other sub-optimum architectures such as hybrid coded modulation (HCM), this optimum performance can be achieved will different constellation labelings, which shows that the proposed transmission scheme is more flexible than the previous ones. The theoretical results are validated with Monte Carlo simulations of the proposed architecture using LDGM codes as component codes of the MLC scheme.