A wireless communication apparatus configured to operate as beamformer and comprising circuitry configured to: - transmit a High Throughput, HT, capability element to another wireless communication apparatus configured to operate as beamformee, the HT capability element including a transmit beamforming capability field, wherein the HT capability element and the transmit beamforming capability field are defined in IEEE standard 802.1 In and wherein the transmit beamforming capability field includes capability information and has 32 bits named as bit B0 to bit B31; and - perform wireless communication with the another wireless communication apparatus based on the capability information, wherein the transmit beamforming capability field includes maximum dimension information indicating a maximum number of rows of a feedback matrix for the transmission beamforming, in which maximum number the wireless communication apparatus can compute a transmission weight matrix for beamforming, wherein the feedback matrix has a first fixed number N of columns and a second number M of rows, the second number corresponding to the maximum number or a lower number, N corresponding to a number of antennas of the beamformer and M corresponding to a number of antennas of the beamformee, and wherein the maximum dimension information has two bits, which are located at bits B25 and B26 in the transmit beamforming capability field and by which the second number of rows in the range from 1 to 4 is indicated, wherein the feedback matrix having one row and N columns is defined as a maximum if the value thereof is zero, the feedback matrix having two rows and N columns is defined as a maximum if the value thereof is one, the feedback matrix having three rows and N columns is defined as a maximum if the value thereof is two, and the feedback matrix having four rows and N columns is defined as a maximum if the value thereof is three, thereby representing the spatial dimension number allowed to channel state information when receiving a sounding packet. - transmit a High Throughput, HT, capability element to another wireless communication apparatus configured to operate as beamformee, the HT capability element including a transmit beamforming capability field, wherein the HT capability element and the transmit beamforming capability field are defined in IEEE standard 802.1 In and wherein the transmit beamforming capability field includes capability information and has 32 bits named as bit B0 to bit B31; and - perform wireless communication with the another wireless communication apparatus based on the capability information, wherein the transmit beamforming capability field includes maximum dimension information indicating a maximum number of rows of a feedback matrix for the transmission beamforming, in which maximum number the wireless communication apparatus can compute a transmission weight matrix for beamforming, wherein the feedback matrix has a first fixed number N of columns and a second number M of rows, the second number corresponding to the maximum number or a lower number, N corresponding to a number of antennas of the beamformer and M corresponding to a number of antennas of the beamformee, and wherein the maximum dimension information has two bits, which are located at bits B25 and B26 in the transmit beamforming capability field and by which the second number of rows in the range from 1 to 4 is indicated, wherein the feedback matrix having one row and N columns is defined as a maximum if the value thereof is zero, the feedback matrix having two rows and N columns is defined as a maximum if the value thereof is one, the feedback matrix having three rows and N columns is defined as a maximum if the value thereof is two, and the feedback matrix having four rows and N columns is defined as a maximum if the value thereof is three, thereby representing the spatial dimension number allowed to channel state information when receiving a sounding packet. wherein the transmit beamforming capability field includes maximum dimension information indicating a maximum number of rows of a feedback matrix for the transmission beamforming, in which maximum number the wireless communication apparatus can compute a transmission weight matrix for beamforming, wherein the feedback matrix has a first fixed number N of columns and a second number M of rows, the second number corresponding to the maximum number or a lower number, N corresponding to a number of antennas of the beamformer and M corresponding to a number of antennas of the beamformee, and wherein the maximum dimension information has two bits, which are located at bits B25 and B26 in the transmit beamforming capability field and by which the second number of rows in the range from 1 to 4 is indicated, wherein the feedback matrix having one row and N columns is defined as a maximum if the value thereof is zero, the feedback matrix having two rows and N columns is defined as a maximum if the value thereof is one, the feedback matrix having three rows and N columns is defined as a maximum if the value thereof is two, and the feedback matrix having four rows and N columns is defined as a maximum if the value thereof is three, thereby representing the spatial dimension number allowed to channel state information when receiving a sounding packet.