Multiuser Detection for MIMO-OFDM Systems Based on Known Partial CSI

In this paper,a novel method for signal recovery in multiuser multiple-input multiple-output(MIMO) orthogonal frequency division multiplex(OFDM) systems with known partial channel state information(CSI) is proposed. The effect of the dispersive channel in a multiuser MIMO-OFDM system can be treated as a set of instantaneous mixtures from the viewpoint of frequency bin(FB). Upon the arrival of a new user,the new interferences are introduced which results an expanding mixture. If the CSI before the arrival of new user is known, it can be employed to recover the transmitted signals, rather than the bandwidth waste pilot symbols. In the proposed method, from the second order statistics of the received signals, the parameters of the mixture caused by the new user are extracted. Then the signals belong to different users are separated at each FB, where the new joined user´s signals still retain a phase distortion. This distortion can be removed by the existing non-coherent detection method.