Blind channel estimation for MIMO-OFDM systems with repeated time-domain symbols

Cyclic prefix (CP), virtual carriers (VCs), and multiple receive antennas are conventionally used to construct the required signal and noise subspaces for subspace-based blind channel estimation approaches in multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. Different to the conventional approaches, this paper proposes a subspace-based blind channel estimation approach with repeated time-domain symbols. A new signal model can then be developed to generate the required noise subspace for channel estimation. Simulation results demonstrate that the proposed subspace-based blind channel estimation method outperforms the approach with VCs in terms of normalized mean-squared error (NMSE) under the same transmission rate.