A Decision-feedback Receiver for Channels with Strong Intersymbol Interference

This paper deals with the problem of equalizing channels containing strong intersymbol interference. Typical of such channels are those of digital magnetic recording systems and data communication systems with partial-response signaling. First we discuss reasons that a conventional receiver with a linear equalizer cannot efficiently compensate for distortion in such channels. We then present a new receiver configuration in which the equalizer and quantizer are embedded in an inverse filter circuit that eliminates major intersymbol interference components. This configuration allows us to use a simple iteration algorithm to adaptively adjust the equalizer. Application of the scheme to digital magnetic recording data is discussed as an illustrative example.