Patent ID: 8364206

Claim:
A base station apparatus comprising: a first antenna for emitting radio waves at a first tilt angle; a second antenna for emitting radio waves at a second tilt angle different from the first tilt angle; a radio unit for sending and receiving radio signals through the first and second antennas; and a baseband unit for sending and receiving signals to and from a terminal through the first antenna and/or the second antenna by switching between a first mode in which a signal is sent to the terminal with one of the first antenna and the second antenna and a second mode in which the signal is sent to the terminal with a plurality of antennas that include the first antenna and the second antenna; wherein the signal is sent in the first mode when a difference between reception quality of the signal sent from the base station apparatus and reception quality of the signal sent from an adjacent base station apparatus adjacent to the base station apparatus is smaller than a predetermined reference, each reception quality being measured at the terminal; and the signal is sent in the second mode when the difference between the reception quality of the signal sent from the base station apparatus and the reception quality of the signal sent from the adjacent base station apparatus adjacent to the base station apparatus is equal to or larger than the predetermined reference, each reception quality being measured by the terminal.