A simple test for multistage MIMO detection

Maximum likelihood detection of multiple input multiple output (MIMO) signals requires computational capabilities that are challenging to obtain in most practical systems. Although many alternative schemes have been devised to reduce the operational burden, the complexity of algorithmic schemes remains much higher than that of equalizer-based techniques, which in turn provide poor performance in terms of error rate. In this paper, we derive a low-complexity test that allows to run a more efficient but complex detection scheme only on selected received symbols. The few symbols that are identified as erroneously detected by the low complexity method are the only ones to be reprocessed. The global complexity is hence reduced, typically by more than one order of magnitude, with very little loss in performance