Patent ID: 7035672

Claim:
A wireless communication apparatus that is employed in a multiple-input-multiple-output wireless communication system, comprising: a plurality of antenna units that transmit or receive a radio frequency signal; and a weight controlling unit that gives a weight with respect to each of the antenna units, at least one of the antenna units being formed by an adaptive array antenna unit that has a plurality of antenna elements, and directivity being changed by varying weights with respect to the antenna elements, the weight controlling unit including: an eigenvalue calculating unit that calculates eigenvalues of a matrix represented by the product of a current channel matrix representing the transmission characteristics of wireless transmission channels of the respective antenna units and a conjugate transposed matrix of the current channel matrix; an inverse calculation unit that calculates such a channel matrix as to have all eigenvalues within a predetermined range that includes the average value of the calculated eigenvalues but does not include the smallest one of the calculated eigenvalues; and a directivity adjusting unit that adjusts the directivity of the adaptive array antenna unit, so that the current channel matrix approaches the channel matrix calculated by the inverse calculation unit.