MIMO blind second-order equalization method and conjugate cyclostationarity

The blind identification of vector-valued FIR transfer functions using exclusively second-order statistics of the output has become conventional. The so-called subspace method provides a nice and efficient way of solving the problem. However, the extension to the multi-input/multi-output (MIMO) case is not that straightforward, and, for instance, some indetermination drawbacks may occur. We show in this correspondence that the introduction of some cyclostationarity at the input (which still leads to feasible systems) may lead to an algorithm that is far more satisfactory because for both, it is less prone to indetermination problems, and the required assumptions are not too sophisticated.