A Research For Highly Efficient Estimation In MIMO-OFDM Channel

In this thesis, based on the analysis of the wireless channel characteristic and the matrix of multiuser multiple-input multiple-output(MIMO)-orthogonal division multiplex(OFDM) channel estimation, a novel method for signal recovery in MIMO-OFDM systems with known partial channel state information is proposed. The method is based on the blind channel elimination (BCE) and the viewpoint of blind source separation problem(BSS).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). Both in input and output.the date is taken order with the IDFT/DFT OFDM modulate/demodulate. Upon the arrival of a new user, the new interferences are introduced which results an expanding mixture. In this method, from the second order statistics of the received signals, the parameters of the mixture caused by extract the new user information. Then the signals belong to different users are separated at each FB, where the new joined user's signals still retain a phase distortion. The adjusted phases are decorrelated, and the initial values of recovery signal is obtained. That phase can be treated as an unknow carrier phase in single carrier system, and it can be eliminated by existing detection. The validity of the proposed method is demonstrated by computer simulations.