A base station apparatus is disclosed. The base station includes multiple antennas; a first pre-encode processing unit which multiplies one or more first weights with one or more common pilot channels; a second pre-encode processing unit which multiplies, with the one or more common pilot channels, one or more second weights which are orthogonal to the first weights; and a combining unit which combines the first-weights-multiplied common pilot channels and the second-weights-multiplied common pilot channels, wherein the combined common pilot channels are transmitted from the multiple antennas.