Semi-blind multi-user MIMO channel estimation based on Capon and MUSIC techniques

We consider the problem of simultaneous estimation of the channel state information (CSI) of several transmitters that use orthogonal space-time block codes to communicate with a single receiver. Based on the generalizations of the Capon and MUSIC techniques, we propose two novel algorithms to estimate multi-user MIMO channels. These algorithms estimate the subspace spanned by the user channels blindly and use only a few training blocks to extract the users´ CSI from this subspace.