1. A method for updating a weight vector for input signals from a plurality of antennas of a wireless communication system, comprising: setting an initial weight vector for weighting the input signals; separating desired signals from the input signals; obtaining auto-covariance matrixes of the separated desired signals and the input signals, respectively; computing an eigenvalue that maximizes a ratio of a vector that is a multiplication of the auto-covariance matrix of the separated desired signals and the initial weight vector over a vector that is a multiplication of the auto-covariance matrix of the input signals and the initial weight vector; generating a new weight vector by adding a vector to the initial weight vector, wherein said added vector is proportional to the multiplication of the inverse of a diagonal matrix of the auto-covariance matrix of the input signals and a vector made from the multiplication of a vector of the separated desired signals and the initial weight vector and the inverse of the eigenvalue.