An Efficient Subspace Method for the Blind Identification of Multichannel FIR Systems

We present a novel method for the blind identification of linear, single-input multiple-output (SIMO) finite- impulse-response (FIR) systems, based on second-order statistics. Our approach, called the truncated transfer matrix method (TTM) proceeds in two major steps: first, the SVD analysis of the lagged covariance matrix gives the subspace of the clipped system transfer matrix and second, the block-Toeplitz structure of the transfer matrix gives extra constraints that allow us to reconstruct the matrix through the solution of a linear system of equations. The proposed TTM method is analytical (no optimization procedure involved), and it is robust to noise. We find that the method comes with an increased computational cost but it significantly outperforms state of the art second-order methods in low signal-to-noise ratio (SNR) situations.