US Patent 9680544 Beamforming codeword exchange between base stations

A first base station receives from a second base station at least one message comprising beamforming information indicating at least one second beamforming codeword. The at least one second beamforming codeword has a number of rows or columns equal to or less than a number of antenna ports employed by the second base station for beamforming. The first base station selects at least one first beamforming codeword. The selection is based, at least in part, on the beamforming information. The first base station transmits employing the at least one first beamforming codeword, signals on at least one resource block.