Spatio-temporal blind adaptive multiuser detection

We propose blind multiuser detection schemes with antenna arrays, which is based on signal subspace estimation, They are a multichannel extension of the decorrelating and minimum mean-square-error detectors, and therefore they share their immunity to near-far effects. The blind scheme may be seen as an extension of the results in of Wang and Poor. However it is seen that compared with the latter results when spatial diversity is considered, the proposed spatio-temporal detectors offer, with little attendant increase in computational complexity, a better performance. A blind adaptive implementation based on a new orthogonal PAST (projection approximation subspace tracking) algorithm, which is shown to be efficient for subspace tracking, is proposed. Also, we develop a blind estimation of spatial signature based on the orthogonality between noise and signal subspaces, It is seen that the blind adaptive multiuser detection and blind spatio temporal signature estimation can be integrated jointly.