US Patent 9826442 Beam information exchange between base stations

According to some aspects, a first base station employing a first beamforming codebook may receive a second beamforming codebook from a second base station. The first beamforming codebook may comprise a plurality of beamforming codewords associated with the first base station, and the second beamforming codebook may comprise a plurality of beamforming codewords associated with the second base station. The first base station may receive at least one message from the second base station indicating a subset of the plurality of beamforming codewords associated with the second base station. The first base station may select one or more first beamforming codewords from the first beamforming codebook based on the indicated subset of the plurality of codewords associated with the second base station. The first base station may transmit signals to at least one wireless device employing the one or more first beamforming codewords.