Patent ID: 7848444

Claim:
A wireless communication system for performing data transmission from a first terminal including a first number of antennas to a second terminal including a second number of antennas using spatially multiplexed streams, 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 channel estimation maximum dimension of the first terminal; training means for transmitting a packet from the second terminal to the first terminal according to the channel estimation maximum dimension of the first terminal and the first number of antennas, the packet including a training series for exciting a backward channel matrix having the first number of rows and a third number of columns, the third number being an integer equal to or less than the channel estimation maximum dimension; transmission weight matrix computation means for dividing the training series received by the antennas of the first terminal into the third number of streams to prepare the backward channel matrix, thereby obtaining a transmission weight matrix for beamforming when transmitting forward data using the backward channel matrix; and beamforming means for performing beamforming in transmission signals from 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.