Patent ID: 7873113

Claim:
A radio communication method for use in a radio communication system in which radio communication is performed between a transmitter having a plurality of transmission antennas and a receiver having a plurality of reception antennas, said method comprising: selecting an antenna group which satisfies a first selection criterion relating to communication quality, out of a plurality of antenna groups, each of which is composed of some of the transmission antennas and some of the reception antennas; selecting a combination which satisfies a second criterion relating to communication quality, out of combinations of the transmission antennas and the reception antennas which are included in the selected antenna group; evaluating whether or not any combination, out of the combinations, exists which satisfies a criterion relating to multiple-input-multiple-output (MIMO) communication in which the number of reception antennas is equal to the number of transmission antennas; performing, once it is evaluated that one of the combinations exists which satisfies the criterion, MIMO communication using the one combination of transmission antennas; and performing, once it is evaluated that none of the combinations exists which satisfies the criterion, precoding transmission using all of the transmission antennas included in the combinations.