Fast Semi-Blind Channel Estimation for MIMO-OFDM Systems With Virtual Carriers
Novel blind and semi-blind subspace channel estimations are proposed for Multiple-Input Multiple-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) systems in the presence of Virtual Carriers (VC). Slow convergence rate is a drawback of subspace method in deriving the noise/signal subspaces from the second-order statistics of received signals, especially when the dimension of received signals is large. In this paper, the block matrix scheme is proposed to generate a group of sub-vectors from each OFDM symbols. The dimension of subvectors is reduced and the number of equivalent signals is increased, and therefore, the convergence rate of channel estimation is enhanced.