Patent ID: 8879496

Claim:
A method comprising: a) receiving, by a first base station from a second base station, at least one application protocol message, said first base station and said second base station configured to communicate with a plurality of wireless devices employing a downlink carrier, said downlink carrier comprising a plurality of resource blocks, said at least one application protocol message comprising a downlink beamforming information element for at least one resource block in said downlink carrier, said downlink beamforming information element indicating a second beamforming codeword employed by said second base station for said at least one resource block, said second beamforming codeword: i) having a number of rows or columns equal to a number of antenna ports employed by said second base station for beamforming on said downlink carrier; ii) included in a second beamforming codebook; and iii) referenced by an index, correspondence between said beamforming codeword and said index being defined by an application protocol message received prior to said at least one application protocol message reception; b) selecting, by said first base station for said at least one resource block, a first beamforming codeword from a first beamforming codebook, said selection being based, at least in part, on said downlink beamforming information element received from said second base station; and c) transmitting, by said first base station, employing said first beamforming codeword, signals on a subset of said at least one resource block to a wireless device.