Tri-diagonalization of the covariance matrix generated by the multistage Wiener filter for whitening blind signals

The multistage Wiener filter (MWF) has been shown to provide performance benefits that meet or exceed MMSE performance. The principle behind the MWF is a whitening operation naturally created by a tri-diagonalization of the covariance matrix at each stage. In blind mode, tri-diagonalization of the implicit covariance matrix structure no longer occurs, resulting in sub-optimal performance. In this paper, we show, using the CDMA system as an example, that tri-diagonalization can occur for blind mode using larger sample support or spatial diversity at the transmit or receive antenna.