Date Added: Jan 2012
This paper deals with joint data detection and channel estimation for frequency-selective Multiple-Input Multiple-Output (MIMO) systems with focus on the analysis of the channel estimator. First, the authors present a scheme alternating between joint Viterbi detection and least squares channel estimation and analyze its performance in terms of unbiasedness. Since in the proposed technique the channel estimator exploits both known pilot symbols (non-blind) as well as unknown information bearing symbols (blind), this channel identification scheme is referred to as semi-blind. Second, they derive the Cramer-Rao Lower Bound (CRLB) for semi-blind channel estimation of frequency-selective MIMO channels, which provides a theoretical lower bound of the achievable Mean Squared Error (MSE) of any unbiased estimator.