A method performed by a radio network node for determining a partitioning of a first signal into one or more parts to be transmitted to a first radio node. The radio network node comprises two or more antennas, each associated with a respective radio chain. The radio network node and the radio node operate in a wireless communications network. The radio network node determines a number of radio chains, to be used to send the first signal, and determines a partitioning of the first signal into the one or more parts of the first signal over the determined number of radio chains. The one or more parts are to be transmitted to the first radio node. The radio network node determines the number of radio chains and the partitioning based on a scheduling decision associated with the radio network node, and one or more parameters.