Fisher-Information-Matrix Based Analysis of Semiblind MIMO Frequency Selective Channel Estimation
The authors present a study of Semi-Blind (SB) estimation for a Frequency-Selective (FS) Multiple-Input Multiple-Output (MIMO) wireless channel using a novel Fisher-Information Matrix (FIM) based approach. The frequency selective MIMO system is modeled as a matrix Finite Impulse Response (FIR) channel, and the transmitted data symbols comprise of a sequence of pilot symbols followed by the unknown blind symbols. They present a key result relating the rank of the FIM to the number of blindly identifiable parameters. They then present a novel-Maximum-Likelihood (ML) scheme for the semi-blind estimation of the MIMO FIR channel. They derive the Cramer-Rao Bound (CRB) for the semi-blind scheme.