1. A method comprising: receiving at least a first and a second spatial streams of transmit points, each spatial stream being associated with a transmitting antenna, over a multiple input multiple output (MIMO) channel associated with a channel matrix H, wherein the transmit points are modulated based on a square modulation associated with a square constellation of points defined by x and y components respectively; performing a naïve search of all possible transmit points of the second spatial stream by generating, for each transmit point of the second spatial stream, a single-input single-output (SISO) decoding problem in terms of transmit points of the first spatial stream; decomposing the x and y components of the points of the first spatial stream based on the naïve search, thus creating two one-dimensional problems from each two-dimensional decoding problem; and performing a reduced search of the transmit points of the first spatial stream, wherein the reduced search is performed for each point only along a single column and a single row associated with the decomposed x and y components respectively.