Patent ID: 8228878
Filing Date: 2012-07-24
Classification: H01Q,H04B,H04L

Abstract:
1. A method of interference mitigation for a repeater station, the repeater station comprising at least one antenna with two or more antenna elements with which the repeater station is configured to communicate signals wirelessly, said method comprising: determining a channel representation of a feedback channel from an output connection of the repeater station to an input connection of the repeater station, wherein the channel representation comprises a channel matrix of matrix elements, and wherein the feedback channel is represented by a transfer function or impulse response corresponding to various antenna elements of the at least one antenna; setting weights for the various antenna elements based upon the channel representation, to suppress signal transfer from the output connection to the input connection of the repeater station, said weights being amplifying or delaying signals to or from the various antenna elements, to suppress signal transfer from the output connection to the input connection of the repeater equipment; and wherein the weights are determined to correspond to: elements of a weight matrix in the null space of the matrix representation of the feedback channel; or elements of a weight matrix in the null space of the matrix representation of the feedback channel multiplied by a predetermined receive matrix; or elements of a matrix in a predefined extension of the null space of the matrix representation of the feedback channel, the predefined extension being determined by a number representing a particular number of singular vectors achieved from a singular value decomposition of the matrix representing the feedback channel; or elements of a matrix in a predefined extension of the null space of the feedback channel multiplied by a predetermined receive matrix, the predefined extension being determined by a number representing a particular number of singular vectors achieved from a singular value decomposition of the matrix representing the feedback channel multiplied by a predetermined receive matrix; and further wherein said weights are determined so that the rank of the communications channel provided by the repeater station is greater than one.