Patent ID: 8396107

Claim:
A method for processing user symbols with a generalized decision feedback equalizer (GDFE) based precoder in a base station of a multi-user multiple-input multiple-output (MU-MIMO) wireless system having K user terminals (UTs) which communicate with the base station via an uplink (UL) channel and a corresponding downlink (DL) channel, the method comprising: a processor obtaining an effective downlink (DL) channel matrix H for the DL channel after receiver processing at the user terminals; computing an uplink (UL) covariance matrix D by assuming there are as many user terminals as a number of rows in the effective DL channel matrix H, the UL covariance matrix D being a diagonal matrix; computing a filter matrix C based on the UL covariance matrix D; computing a feedforward filter matrix F based on the filter matrix C; computing an interference pre-cancellation matrix G, based on the feedforward filter matrix F and the filter matrix C, used in a transmitter at an interference pre-cancellation stage of the GDFE precoder; and processing by the processor user symbols by a decision feedback equalizing stage of the GDFE precoder to produce filtered vector symbols; wherein the effective downlink (DL) channel matrix is H= H=[Ĥ 1 H ,Ĥ 1 H , . . . , Ĥ K H ], where Ĥ k is an effective DL channel sub-matrix for the k th UT Ĥ k =S k V k H , where S k and V k are matrices obtained from a singular value decomposition (SVD) of and estimated DL channel matrix H k for the k th UT H k =U k S k V k H .