In this paper we study the problem of minimum variance prediction for
linear time-varying systems. We consider the standard time-varying aut
oregression moving average (ARMA) model and develop a predictor which
guarantees minimum variance prediction for a large class of linear tim
e-varying systems. The predictor is developed based on a pseudocommuta
tion technique for dealing with noncommutativity of linear time-varyin
g operators in a transfer operator framework. We also show connections
between this input-output predictor and the Kalman predictor via an e
xample. (C) 1997 Elsevier Science Ltd.