An enhanced correlation matrix estimation scheme for blind adaptive MMSE receiver

An improved correlation matrix estimation scheme for blind adaptive MMSE receivers for DS-CDMA communications was proposed by Chen and Mitra (see IEEE Journal on Selected Areas on Communications, vol.19, p.1531-43, 2001). Blind adaptive MMSE receivers with the estimation scheme not only maintain the merit of robustness against fading, but achieve performance comparable to the training-sequence based adaptive MMSE receivers. This paper presents an enhanced version of the improved correlation matrix estimation scheme for blind adaptive MMSE detection, which results in a better convergence and tracking property and noticeably improved performance than the original scheme of Chen and Mitra. Theoretical analysis is performed for the flat fading case which predicts the advantages of the new scheme. Detailed computer simulations are also carried out to verify the performance of blind adaptive MMSE receivers with the new estimation scheme.