An apparatus comprising: a signal processor configured to process a first signal and a second signal with a rotation matrix to produce a first processed signal and a second processed signal such that each of the first and second processed signals is a respective different weighted combination of the first and second signals; and a transmitter configured to wirelessly transmit the first processed signal with a first polarization, and to wirelessly transmit the second processed signal with a second polarization that is substantially orthogonal to the first polarization; wherein: the signal processor is configured to, based on received feedback, adjust an angle of rotation of the rotation matrix; wherein: the received feedback comprises an indication of signal quality for signals recovered at a receiver from the first and second processed signals; and the angle of rotation is adjusted based on the indication of signal quality; or wherein the received feedback comprises an indication of an updated value to use for the angle of rotation; or an indication to increment the angle of rotation; or an indication to de-increment the angle of rotation; wherein the rotation matrix is cos ⁢ θ − sin ⁢ θ sin ⁢ θ cos ⁢ θ with θ being an angle of rotation. a signal processor configured to process a first signal and a second signal with a rotation matrix to produce a first processed signal and a second processed signal such that each of the first and second processed signals is a respective different weighted combination of the first and second signals; and a transmitter configured to wirelessly transmit the first processed signal with a first polarization, and to wirelessly transmit the second processed signal with a second polarization that is substantially orthogonal to the first polarization; wherein: the signal processor is configured to, based on received feedback, adjust an angle of rotation of the rotation matrix; wherein: the received feedback comprises an indication of signal quality for signals recovered at a receiver from the first and second processed signals; and the angle of rotation is adjusted based on the indication of signal quality; or wherein the received feedback comprises an indication of an updated value to use for the angle of rotation; or an indication to increment the angle of rotation; or an indication to de-increment the angle of rotation; wherein the rotation matrix is cos ⁢ θ − sin ⁢ θ sin ⁢ θ cos ⁢ θ with θ being an angle of rotation. the signal processor is configured to, based on received feedback, adjust an angle of rotation of the rotation matrix; wherein: the received feedback comprises an indication of signal quality for signals recovered at a receiver from the first and second processed signals; and the angle of rotation is adjusted based on the indication of signal quality; or wherein the received feedback comprises an indication of an updated value to use for the angle of rotation; or an indication to increment the angle of rotation; or an indication to de-increment the angle of rotation; wherein the rotation matrix is cos ⁢ θ − sin ⁢ θ sin ⁢ θ cos ⁢ θ with θ being an angle of rotation. the received feedback comprises an indication of signal quality for signals recovered at a receiver from the first and second processed signals; and the angle of rotation is adjusted based on the indication of signal quality; or wherein the received feedback comprises an indication of an updated value to use for the angle of rotation; or an indication to increment the angle of rotation; or an indication to de-increment the angle of rotation; wherein the rotation matrix is cos ⁢ θ − sin ⁢ θ sin ⁢ θ cos ⁢ θ with θ being an angle of rotation.