An apparatus, comprising: a transceiver adapted for multiple input multiple output, MIMO, beamforming and further adapted for communication with a receiver that feeds back to said transceiver two beamforming matrixes (360, 370) per subband to form N s vector pairs, where N s is a number of beamformed streams in the two beamforming matrixes, and wherein the transceiver is adapted to: linearly interpolate each vector pair in the angle domain along a Grassman manifold to determine an interpolated angle for each beamformed stream, wherein the interpolated angle is computed as θ i (k) = a k θ i, for i = 1,···,N s where a k = | f k − f A f A − f B | is inversely proportional to a frequency spacing between A's subcarrier and B's subcarrier of |f A -f B | and is proportional to a frequency spacing between A's subcarrier and a k-th subcarrier of |f k -f A |, wherein A and B are the two beamforming matrixes; compute an interpolated vector for each interpolated angle on a plane spanned by the vector pair associated with the vector angle; and form an interpolated beamforming matrix comprising the interpolated vectors for each of the beamformed streams, wherein the interpolated beamforming matrix is a unitary matrix or a non-unitary matrix, and the interpolated beamforming matrix is converted to a unitary matrix when the interpolated beamforming matrix is a non-unitary matrix. a transceiver adapted for multiple input multiple output, MIMO, beamforming and further adapted for communication with a receiver that feeds back to said transceiver two beamforming matrixes (360, 370) per subband to form N s vector pairs, where N s is a number of beamformed streams in the two beamforming matrixes, and wherein the transceiver is adapted to: linearly interpolate each vector pair in the angle domain along a Grassman manifold to determine an interpolated angle for each beamformed stream, wherein the interpolated angle is computed as θ i (k) = a k θ i, for i = 1,···,N s where a k = | f k − f A f A − f B | is inversely proportional to a frequency spacing between A's subcarrier and B's subcarrier of |f A -f B | and is proportional to a frequency spacing between A's subcarrier and a k-th subcarrier of |f k -f A |, wherein A and B are the two beamforming matrixes; compute an interpolated vector for each interpolated angle on a plane spanned by the vector pair associated with the vector angle; and form an interpolated beamforming matrix comprising the interpolated vectors for each of the beamformed streams, wherein the interpolated beamforming matrix is a unitary matrix or a non-unitary matrix, and the interpolated beamforming matrix is converted to a unitary matrix when the interpolated beamforming matrix is a non-unitary matrix. linearly interpolate each vector pair in the angle domain along a Grassman manifold to determine an interpolated angle for each beamformed stream, wherein the interpolated angle is computed as θ i (k) = a k θ i, for i = 1,···,N s where a k = | f k − f A f A − f B | is inversely proportional to a frequency spacing between A's subcarrier and B's subcarrier of |f A -f B | and is proportional to a frequency spacing between A's subcarrier and a k-th subcarrier of |f k -f A |, wherein A and B are the two beamforming matrixes; compute an interpolated vector for each interpolated angle on a plane spanned by the vector pair associated with the vector angle; and form an interpolated beamforming matrix comprising the interpolated vectors for each of the beamformed streams, wherein the interpolated beamforming matrix is a unitary matrix or a non-unitary matrix, and the interpolated beamforming matrix is converted to a unitary matrix when the interpolated beamforming matrix is a non-unitary matrix.