Blind channel estimation of MIMO-OFDM by virtual carriers

Multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems are attractive because of their large capacity and high data rate. The proposed method unifies and generalizes the existing subspace-based methods for blind channel estimation in single-input single-output OFDM systems to blind channel estimation. The proposed algorithm can be applied to MIMO-OFDM systems with insufficient CP or no CP. Furthermore, in the case of MIMO system, it exits an ambiguity matrix between the estimated channel coefficient matrix and the true channel matrix. Using second-order blind source separation gets source signal. Simulation results illustrate the mean-square error performance of the proposed method via numerical experiments.