A new approach to iterative decoding on coded MIMO channels

For coded multiple-input multiple-output spatial multiplexing (MIMO-SM) systems, the iterative receiver consists of a MIMO detector and a channel decoder. The sphere decoding (SD) technique can be employed to implement the MIMO maximum likelihood (ML) detection with a lower complexity. However, it is generally required to provide a soft-decision for the MIMO detection rather than a hard-decision for decoding. Hence, some modifications of the SD have been proposed to provide a soft-decision. In this paper, we propose an alternative algorithm that is based on the geometrical point of view. Using the proposed algorithm, the maximum a-posteriori (MAP) detection for the soft-decision can be implemented by the list sphere decoding (LSD) technique. Through simulations, it is shown that the performance is comparable to the existing algorithm.