A mobile communication apparatus that utilizes multiple base station/mobile station antennas and a mobile communication method performed therein are provided. The mobile communication apparatus includes a base station having at least two antennas and at least two mobile stations having at least one antenna, respectively. The base station restores weight information and channel status information from feedback signals received from the mobile stations, determines downlink investigation information that results in maximum transmission channel capacity based on the restored weight information and channel status information, selects mobile stations for simultaneous transmission based on the downlink investigation information, and processes data to be transmitted to the selected mobile stations based on the downlink investigation information.