Patent Document ID: 8571138
Application ID: 13447415
Patent Flag: 1

Claim One:
1. A base station of a multi-user multiple-input multiple-output (MU-MIMO) wireless system having k user terminals (UTs) with L k antennas each, each user terminal (UT) having associated therewith a feedforward filter represented by F 1 , F 2. .. , F k , the base station including a generalized decision feedback equalizer (GDFE) based precoder comprising: a feedforward path; a feedback path; and an interference pre-cancellation block denoted by I−G disposed in the feedback path, I being an identity matrix, G being an interference pre-cancellation matrix; wherein the interference pre-cancellation matrix G in the interference pre-cancellation block is determined by computing a filter matrix C using one of an expression which requires computation of S xx as an input covariance matrix for the downlink channel or an expression which does not require computation of S xx , wherein a feedforward filter matrix F is represented by F=GM H C, where M is a unitary matrix; computing the matrix M using QR decomposition (QRD) of C as 
 C=MR; computing the feedforward filter matrix F as 
 F =BlockDiagonal( R ) where the BlockDiagonal(.) function extracts submatrices F 1 , F 2. .. , F k of size {a k ×L k } from block diagonals of the matrix R, and a k is a number of symbols allotted to the k th user terminal (UT) and equals the rank of F k ; and computing the interference pre-cancellation matrix G as 
 G=FR † where superscript † denotes a Moore-Penrose Generalized Inverse.