Patent ID: 8509366

Claim:
A method for calculating in a receiver a final noise covariance estimate for a first channel, for use in reducing noise in that first channel, wherein the receiver comprises a plurality of antennas and, wherein the final noise covariance estimate is a final estimate of the covariance of the noise received on the first channel between the plurality of antennas of the receiver, the method comprising: calculating a first raw noise covariance estimate, which is an initial estimate of the covariance of the noise received on the first channel between the plurality of antennas of the receiver; calculating at least a second raw noise covariance estimate, which is an initial estimate of the covariance of the noise received on a second channel between the plurality of antennas of the receiver; calculating a first metric for the second channel based on the first and second raw noise covariance estimates, said first metric being a statistical measure indicative of how well the second raw noise covariance estimate describes the noise in the first channel; determining, based on the first metric, whether the second raw noise covariance estimate should be included in the calculation of the final noise covariance estimate for the first channel; calculating the final noise covariance estimate for the first channel using at least the first and second raw noise covariance estimates if it is determined that the second raw noise covariance estimate should be included in the calculation of the final noise covariance estimate for the first channel; and calculating the final noise covariance estimate for the first channel using at least the first raw noise covariance estimate but not the second raw noise covariance estimate if it is determined that the second raw noise covariance estimate should not be included in the calculation of the final noise covariance estimate for the first channel.