Filterbank precoding in the intersymbol interference (ISI) mitigation has recently attracted much attention. Two main areas of such research have been explored. One of them is on filterbank precoding when the ISI channel is known to both the transmitter and the receiver, while the other is on filterbank precoding when the ISI channel is not known to the transmitter or the receiver. This paper is in the second area and the aim is two-fold. We first summarize some recent results on ambiguity resistant filterbank precoders for the ISI mitigation when the ISI channel is not known at the transmitter or the receiver, i.e., for blind equalization. We then present some new results on the construction and characterization of such precoders. The theory presented in this paper applies to both single antenna (SISO) systems and multiple antenna (MIMO) systems as space-time precoding.