Patent ID: 7627045

Claim:
A wireless communication system which carries out data transmission, using multiple spatially multiplexed communication channels between a transmitter and a receiver, comprising: the transmitter configured to transmit user data following a reference signal for channel matrix acquisition, wherein said transmitter obtains transmit weights V for transmitting the user data in a forward direction to said receiver beforehand, weights the reference signal and the user data by V, and transmits the user data following the reference signal over the spatially multiplexed communication channels; the receiver configured to acquire a channel matrix H, based on the reference signal attached preceding the user data, receive the user data, while weighting the user data with receive weights U derived from the channel matrix H, and adaptively estimate the channel matrix H as long as the user data is being received; and a channel characteristics acquisition and adaptive estimation unit HV as a channel matrix from the reference signal weighted by V and continues to perform adaptive estimation of HV' as a channel matrix during the reception of the user data transmitted in the forward direction from said transmitter, and, when transmitting the user data in a reverse direction, following the reception of the user data, predetermines weights V' for data transmission in the reverse direction by obtaining a transposed matrix of H' by multiplying H'V by V H and by singular value decomposition of the transposed matrix of H', where V H corresponds to a matrix of antenna weighting factors at the transmitter.