An efficient tree search algorithm for optimal detection of MIMO signals with channel estimation errors

In this paper, we investigate the optimum detection of MIMO signals in the presence of channel estimation errors. An efficient tree search based detector is proposed for optimal MIMO signal detection, based on the modified ML criterion, which takes channel estimation errors into account. It is shown that this tree search ML detector is almost as computationally efficient as the corresponding sphere decoder, ignoring channel estimation errors. When applied to the MIMO system, concatenated with an outer channel code, the proposed ML detector, taking into account channel estimation errors, achieves significant gain over sphere detectors ignoring channel estimation errors.