A base station apparatus including a receiving unit to receive, from a
terminal, quantized channel state information with respect to a radio
channel from a plurality of transmission antennas of the base station
apparatus to a plurality of receiving antennas of the terminal. A control
unit to determine a control ratio of interference signal to noise with
respect to the radio channel based on the channel state information. A
precoding matrix computing unit to compute a precoding matrix based on
the control ratio of interference signal to noise and a transmission unit
to transmit data to one or more of the connected terminals using the
precoding matrix.