An electronic device is disclosed. The electronic device includes a first antenna array including a plurality of first antenna elements, a second antenna array including a plurality of second antenna elements, and a processor. The processor measures first signal strengths for every a plurality of beam indexes by means of the first antenna array and the second antenna array, determines second signal strengths for every the plurality of beam indexes by means of the first antenna array, and determines a beam index, a signal strength of which is maximal, based on a difference between the first signal strength and the second signal strength corresponding to a beam index selected among the plurality of beam indexes.