Patent Document ID: RE45150
Application ID: 13539193
Patent Flag: 1

Claim One:
1. A wireless communication system which performs data transmission from a first terminal including N antennas to a second terminal including M antennas using spatially multiplexed streams (N is an integer of 2 or more and M is an integer of 1 or more), the system comprising: training request means for requesting transmission of a training signal for exciting a backward channel from the first terminal to the second terminal; training means for transmitting a packet including training series for exciting an N×M backward channel matrix from the second terminal to the first terminal in response to the request; channel matrix preparing means for dividing the training series received by the antennas of the first terminal and constructing the backward channel matrix; transmission weight matrix computation means for obtaining a N×N transmission weight matrix for beamforming at the time of forward data transmission using an N×N channel matrix composed of N columns included in the backward channel matrix in consideration of the number N of antennas of the first terminal, in a case of N<M; 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.