Semiblind channel estimation for MIMO-OFDM

A semiblind method for channel estimation in multiple-input multiple-output (MlMO) orthogonal frequency-division multiplexing (OFDM) systems is proposed. The MIMO-OFDM channel matrix is first estimated blindly up to an ambiguity matrix using the subspace identification algorithm based on the second-order statistics of the channel outputs. The ambiguity matrix is then estimated using a few training symbols. It shows that the number of training symbols required by the proposed semiblind method is significantly less than that used in the training sequence based channel estimation algorithm. The simulation results demonstrate the effectiveness of the proposed algorithm.