A receiver decodes received data streams based on a subset of candidate decoding constellation points. A first stage of a decoder of the receiver selects a subset of candidate decoding constellation points by identifying a decoded value for an initial data stream of the set of data streams. A second stage then applies MMSE error detection to each of the constellation points in the selected subset, and calculates an error metric based on the MMSE error detection results. The decoder selects the constellation points having the lowest error metrics, and uses the selected constellation points as an initial set of points for decoding the next data stream to be decoded.