Interference-aware multi-iterative equalization and detection for frequency-selective MIMO channels

Turbo equalization has demonstrated to be a powerful approach for wireless transmission over frequency-selective channels introducing intersymbol interferences (ISI). Regarding multiple-input multiple-output (MIMO) systems, tree-search based MIMO detection techniques (e.g., sphere detection) are well suited for significantly reducing multi-antenna interferences. However, direct application of these detection techniques under the presence of ISI leads to vast processing complexity, increasing exponentially with the channel length and the number of transmitting antennas. In this paper, a low-complex two-stage approach is described splitting the interference reduction into a frequency-domain equalization stage and a time-domain sphere detection stage. Both are able to take a-priori information into account. Based on this, we derive a novel multi-iterative receiver, enabling powerful and adaptable processing with respect to the dominating interferences.