A method comprising: arranging, in a transmitter, information to be transmitted to a receiver, to a plurality of spatial layers where each spatial layer is associated with a unique precoding configuration amongst the plurality of spatial layers, wherein the information comprises at least one signal that is identical in a plurality of the plurality of spatial layers; performing, in the transmitter, a decorrelation operation across the plurality of spatial layers such that the at least one signal in one of the plurality of spatial layers becomes decorrelated with the at least one signal in another one of the plurality of spatial layers, wherein said performing said decorrelation of the signal is performed across a plurality of sub-bands and comprises: dividing a transmission band allocated for transmission of said information into said plurality of sub-bands; selecting a sub-band-specific phase rotation configuration; and applying the same phase rotation configuration to all spatial layers on the same sub-band, wherein the phase rotation configuration defines a different phase rotation value for at least two spatial layers of the same sub-band, and wherein the phase rotation configuration is configured to comprise phase rotation values selected such that the following orthogonality condition is satisfied: e jφ 0, l 1 e jφ 1, l 1 ⋮ e jφ P − 1, l 1 H × e jφ 0, l 2 e jφ 1, l 2 ⋮ e jφ P − 1, l 2 = 0 where e jφ 0, l 1 to e jφP -1, l 1 define phase rotation values for a first spatial layer l 1, and e jφ 0, l 2 to e jπP -1, l 2 define phase rotation values for a second spatial layer l 2, wherein P is the number of phase rotation configurations; and the method further comprising causing, in the transmitter, transmission of a transmission signal comprising the information in the plurality of spatial layers to the receiver. arranging, in a transmitter, information to be transmitted to a receiver, to a plurality of spatial layers where each spatial layer is associated with a unique precoding configuration amongst the plurality of spatial layers, wherein the information comprises at least one signal that is identical in a plurality of the plurality of spatial layers; performing, in the transmitter, a decorrelation operation across the plurality of spatial layers such that the at least one signal in one of the plurality of spatial layers becomes decorrelated with the at least one signal in another one of the plurality of spatial layers, wherein said performing said decorrelation of the signal is performed across a plurality of sub-bands and comprises: dividing a transmission band allocated for transmission of said information into said plurality of sub-bands; selecting a sub-band-specific phase rotation configuration; and applying the same phase rotation configuration to all spatial layers on the same sub-band, wherein the phase rotation configuration defines a different phase rotation value for at least two spatial layers of the same sub-band, and wherein the phase rotation configuration is configured to comprise phase rotation values selected such that the following orthogonality condition is satisfied: e jφ 0, l 1 e jφ 1, l 1 ⋮ e jφ P − 1, l 1 H × e jφ 0, l 2 e jφ 1, l 2 ⋮ e jφ P − 1, l 2 = 0 where e jφ 0, l 1 to e jφP -1, l 1 define phase rotation values for a first spatial layer l 1, and e jφ 0, l 2 to e jπP -1, l 2 define phase rotation values for a second spatial layer l 2, wherein P is the number of phase rotation configurations; and the method further comprising causing, in the transmitter, transmission of a transmission signal comprising the information in the plurality of spatial layers to the receiver. dividing a transmission band allocated for transmission of said information into said plurality of sub-bands; selecting a sub-band-specific phase rotation configuration; and applying the same phase rotation configuration to all spatial layers on the same sub-band, wherein the phase rotation configuration defines a different phase rotation value for at least two spatial layers of the same sub-band, and wherein the phase rotation configuration is configured to comprise phase rotation values selected such that the following orthogonality condition is satisfied: e jφ 0, l 1 e jφ 1, l 1 ⋮ e jφ P − 1, l 1 H × e jφ 0, l 2 e jφ 1, l 2 ⋮ e jφ P − 1, l 2 = 0 where e jφ 0, l 1 to e jφP -1, l 1 define phase rotation values for a first spatial layer l 1, and e jφ 0, l 2 to e jπP -1, l 2 define phase rotation values for a second spatial layer l 2, wherein P is the number of phase rotation configurations; and the method further comprising causing, in the transmitter, transmission of a transmission signal comprising the information in the plurality of spatial layers to the receiver.