The quality of signals during SDMA is raised.In an uplink, a signal processing unit receives signals respectively from a plurality of terminal apparatuses which have been multiple-accessed by division of time. It derives receiving channel characteristics corresponding to the plurality of terminal apparatuses, respectively, for each time slot. In a downlink, the signal processing unit derives transmitting channel characteristics from the receiving channel characteristics derived and, based on the transmitting channel characteristics derived, it transmits signals respectively to the plurality of terminal apparatuses to which SDMA has been performed. In the downlink, a control unit allocates channels to the plurality of terminal apparatuses, respectively, in a manner that the plurality of terminal apparatuses are multiple-accessed by SDMA; and in the uplink it allocates channels to the plurality of terminal apparatuses, respectively, in a manner that the plurality of terminal apparatuses are multiple-accessed by TDMA.