The authors construct a class of elementary nonparametric output predictors
of an unknown discrete-time nonlinear fading memory system, Their algorith
ms predict asymptotically well for every bounded input sequence, every dist
urbance sequence in certain classes, and every linear or nonlinear system t
hat is continuous and asymptotically time-invariant, causal, and with fadin
g memory, The predictor is based on k(n)-nearest neighbor estimators from n
onparametric statistics. It uses only previous input and noisy output data
of the system without any knowledge of the structure of the unknown system,
the bounds on the input, or the properties of noise, Under additional smoo
thness conditions the authors provide rates of convergence for the time-ave
rage errors of their scheme. Finally, they apply their results to the speci
al case of stable linear time-invariant (LTI) systems.