Sufficient conditions of the redundancy-transform for the blind single channel identification

A subspace method to blindly estimate finite impulse response channels has been considered using redundancy-transform in transmitters. We find sufficient conditions for channel identifiability and observe that channels can be identified without restrictions on their zeros if we properly choose a redundancy matrix to satisfy certain conditions. From these conditions, we also derive another method called the orthogonal subchannel method. This method also can guarantee identifiability of channels without restrictions on their zeros.