A wireless base station apparatus that communicates with a plurality of terminals via spatial multiplexing includes: an active array antenna to transmit a first transmit signal; sector antennas to transmit second transmit signals; and a digital signal processor that generates the first transmit signal that is transmitted from the active array antenna and generates the second transmit signals that are transmitted from the sector antennas, the second transmit signals being transmit signals for eliminating interference between the terminals generated by the first transmit signal.