A Modified Blind MMSE Multi-user Detection Algorithm Based on Subspace Tracking

A modified blind MMSE multi-user detection (MUD) algorithm based on subspace tracking is presented. The modified MMSE just employs signal subspace and avoids performance deterioration induced by eigenvalue estimation error. The proposed method exploits the orthogonal projection approximation subspace tracking (OPAST) algorithm for subspace estimation, since it guarantees the orthogonality of the weight matrix spanned by the signal subspace in every iteration, which must be meet in the modified detector. The numerical simulation results show the substantial performance improvement of our suggested approach over OPAST MUD and PASTd MUD.