On Bidirectional Preestimates and Their Application to Identification of fast Time-Varying Systems

When applied to identification of time-varying systems, such as rapidly fading telecommunication channels, adaptive estimation algorithms built on the local basis function (LBF) principle yield excellent tracking performance but are computationally demanding. The subsequently proposed fast LBF (fLBF) algorithms, based on the preestimation principle, allow a substantial reduction in the complexity without significant performance losses. We propose a novel preestimator, called bidirectional, which further improves performance of the fLBF scheme.