A method of determining precoding information for beamforming between a sender and a receiver the method includes determining a first precoding vector of a first signal layer based on partial channel state information of a channel between the sender and the receiver. The method also includes determining a first guess vector based on long-term characteristics of the channel between the sender and the receiver. A grouping of antennas of the sender is defined and a phase shift value for each group of antennas is specified. The method further includes determining a second precoding vector in the sender of a second signal layer by multiplying each element in the first guess vector with the phase shift value specified for the group of antennas associated with said element in the first guess vector.