Wireless communication method, wireless communication system, and wireless communication apparatus

A wireless communication system that is capable of performing multiple-input multiple-output communication using a wireless communication apparatus having N antennas, where N is an integer of 2 or greater, the system comprising:

• a first inverse-matrix determining unit that determines, using a channel matrix for a first antenna selected from the N antennas, a first inverse matrix of the channel matrix;
• a second inverse-matrix determining unit that determines, with respect to an (n+1)th antenna selected from antennas other than the first to nth antennas already selected from the N antennas, where n=1, 2, . . . , up to L−1, and L represents a given number of antennas used and is an integer of 2 or greater and smaller than or equal to N, a second inverse matrix of a channel matrix for a group of the first to (n+1)th antennas, by performing computation using a value from one of the first inverse matrix and the second inverse matrix for a group of the first to nth antennas;
• an antenna selector that determines, from a plurality of combinations of the L antennas selected from the N antennas, a combination with which an inverse matrix value determined by the first and second inverse-matrix determining units satisfies an antenna selection criterion, as the L antennas used for communication;
• and
• an antenna selection controller that executes control for performing communication using the L antennas selected by the antenna selector.

A wireless communication apparatus that is used in a wireless communication system capable of performing multiple-input multiple-output communication and that performs communication with another wireless communication apparatus having N antennas, where N is an integer of 2 or greater, the wireless communication apparatus comprising:

• a first inverse-matrix determining unit that determines, using a channel matrix for a first antenna selected from the N antennas, a first inverse matrix of the channel matrix;
• a second inverse-matrix determining unit that determines, with respect to an (n+1)th antenna selected from antennas other than the first to nth antennas already selected from the N antennas, where n=1, 2, . . . , up to L−1, and L represents a given number of antennas used and is an integer of 2 or greater and smaller than or equal to N, a second inverse matrix of a channel matrix for a group of the first to (n+1)th antennas, by performing computation using a value from one of the first inverse matrix and the second inverse matrix for a group of the first to nth antennas;
• an antenna selector that determines, from a plurality of combinations of the L antennas selected from the N antennas, a combination with which an inverse matrix value determined by the first and second inverse-matrix determining units satisfies an antenna selection criterion, as the L antennas used for the communication;
• and
• a transmitting unit that transmits, to the wireless communication apparatus having the N antennas, information regarding the L antennas selected by the antenna selector.

A wireless communication apparatus that is used in a wireless communication system capable of performing multiple-input multiple-output communication and that has N antennas, where N is an integer of 2 or greater, the wireless communication apparatus comprising:

• a first inverse-matrix determining unit that determines, using a channel matrix for a first antenna selected from the N antennas, a first inverse matrix of the channel matrix;
• a second inverse-matrix determining unit that determines, with respect to a (n+1)th antenna selected from antennas other than the first to nth antennas already selected from the N antennas, where n=1, 2, . . . , up to L−1, and L represents a given number of antennas used and is an integer of 2 or greater and smaller than or equal to N, a second inverse matrix of a channel matrix for a group of the first to (n+1)th antennas, by performing computation using a value from one of the first inverse matrix and the second inverse matrix for a group of the first to nth antennas;
• an antenna selector that determines, from a plurality of combinations of the L antennas selected from the N antennas, a combination with which an inverse matrix value determined by the first and second inverse-matrix determining units satisfies an antenna selection criterion, as the L antennas used for communication;
• and
• an antenna selection controller that executes control for performing communication using the L antennas selected by the antenna selector.