| CPC H04B 7/0617 (2013.01) [H04W 16/28 (2013.01)] | 16 Claims | 

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               1. A communication device that performs beamforming, the communication device comprising: 
            an antenna array configured to simultaneously form a first vertical beam and a second vertical beam for an arbitrary time; 
                a transceiver configured to transmit and receive a signal using a double beam including the first vertical beam and the second vertical beam; and 
                a processor configured to determine, using a K-means interference avoidance (KIA) algorithm, a first optimal vertical tilting angle of the first vertical beam based on Inter-Beam Interference (IBI) of the second vertical beam, and determine a second optimal vertical tilting angle of the second vertical beam based on the IBI of the first vertical beam, 
                wherein the KIA algorithm is an algorithm using K-means clustering in which the IBI is included as a variable of an objective function, and is configured to cluster user equipments into a first cluster including at least one user equipment and a second cluster including at least one user equipment in a single cell. 
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