Methods (10) and devices (20; 30) for configuring multiple input multiple output, MIMO, wireless transmissions are provided. The method (10) comprises: participating (11), by a first network node (20), in a MIMO wireless transmission between a first network node (20) and a second network node 30 of a wireless network (20, 30), the wireless transmission being associated with a spatial channel matrix (40); while participating (11) in the MIMO wireless transmission: identifying (12), by the first network node (20) and in the spatial channel matrix (40), at least one spatial channel sub-matrix (41) having full rank; determining (13), by the first network node (20) and for each identified spatial channel sub-matrix (41), a candidate transmit configuration for the second network node (30); selecting (14), by the first network node (20) and from the determined candidate transmit configurations, a transmit configuration for the second network node (30); and configuring (15), by the first network node (20), the second network node (30) to use the transmit configuration.