A radio communication system and scheduling method where, when data are
transmitted from a plurality of transmit antennas to respective different
mobile station apparatuses, all the mobile station apparatuses precisely
receive data addressed thereto. A scheduler (104) performs scheduling
that determines a data transmit order, depending on the numbers of
receive antennas of the respective mobile station apparatuses, and
notifies a transmit antennas assignment signal generator (124) of which
transmit antenna is assigned which mobile station apparatus's sub-stream
as the scheduling result. A number of receive antennas notifying signal
decoder (122) decodes the number of receive antennas notifying signals
and notifies the number of the receive antennas of each mobile station
apparatus to the scheduler (104). The transmit antennas assignment signal
generator (124) generates the transmit antennas assignment signal
indicating which transmit antenna is assigned which mobile station
apparatus's sub-stream.