Prekoodausmenetelmä data transmission MIMO radio system

A method of transmitting a transmit vector comprising symbols to be delivered within a resource unit from a transmitting station with one or more transmit antennas to one or more receiving stations with one or more receive antennas. The method comprises obtaining information on the state of channels between the one or more transmit antennas and the one or more receive antennas; and computing, on the basis of the channel states between the one or more transmit antennas and the one or more receive antennas, a covariance matrix Rnn, a combined channel matrix H, and a block-diagonal linear operator V of decoding matrices of the receiving stations. The transmit vector is multiplied with a precoding matrix P fulfilling the equations (HHVHVH=λI)P=HHVH Vi(HiPPHHiH+Rnn,i)=PiHHiH, i=1 . . . K trace(PHP)=Ptr and corresponding performing filtering in the receiving station using a receiver filter corresponding to the block-diagonal linear operator V.