Patent ID: 8260198

Claim:
A wireless communication system for transmitting spatially multiplexed streams from a first terminal including a first number of antennas to a second terminal including a second number of antennas, the first number being an integer equal to or greater than two, and the second number being an integer equal to or greater than one, the system comprising: notifying means for notifying the second terminal of a maximum dimension when computing a transmission weight matrix for beamforming of the first terminal, the maximum dimension being an integer equal to or less than the first number; training means for transmitting a packet including a training sequence, from the first terminal to the second terminal, the training sequence corresponding to the first number of antennas of the first terminal and the second number of antennas of the second terminal; channel matrix estimation means for dividing the training sequence received by the antennas of the second terminal into a second number of streams and estimating a channel matrix; channel information feedback means for suppressing a dimension number of the channel matrix estimated by the second terminal to a third number of rows and the first number of columns, and feeding back the suppressed channel matrix to the first terminal in consideration of the maximum dimension when computing the transmission weight matrix for beamforming in the first terminal, if the first number is less than the second number, wherein the third number is equal to or less than the maximum dimension; transmission weight matrix computation means for obtaining the transmission weight matrix for beamforming when transmitting data from the first terminal to the second terminal using the channel matrix having the third number of rows and the first number of columns fed back from the second terminal to the first terminal; and beamforming means for performing beamforming in transmission signals of the antennas of the first terminal using the transmission weight matrix for beamforming when a data packet is transmitted from the first terminal to the second terminal.