A novel approach for blind estimation of a MIMO channel including phase unwrapping ambiguity elimination

In this paper, a novel method for blind estimation of a multiple input multiple output (MIMO) channelis described. Opposite to the conventional blind estimation algorithms that use singular valuedecomposition (SVD) or eigenvalue decomposition (EVD), it employs a simple coding scheme anda square root algorithm to recover the channel state information (CSI). The block coding scheme accompanyingthe proposed estimation approach requires a block encoder only at the transmitter. Theproposed block coding scheme is spectral efficient as it offers the full coding rate when the numbersof transmitting and receiving antennas are equal. When only two transmitting and two receiving antennasare used, the coding scheme reduces the noise power to half of the original noise power. Thephase ambiguity accompanying the blind approach to channel estimation is eliminated with only onesymbol pilot sequence.