Patent ID: 7292661

Claim:
An iterative equalizer for a data communication system for recovering received data transmitted over a data channel comprising: a first linear filter for filtering a block of received data according to first filter parameters to generate first-filtered data; a combiner for modifying the first-filtered data with second-filtered data to generate modified data; a decision device for generating modified tentative decisions on all data in the block based on the modified data, the modified tentative decisions being modified with respect to tentative decisions of a previous iteration, said modified tentative decisions being used to subtract out an estimate of the intersymbol interference; and a second linear filter for causally and anticausally filtering said block of tentative decisions from a previous pass according to second filter parameters to generate said second-filtered data so as to produce an estimate of the intersymbol interference; wherein said received block of data is filtered more than once by multiple non-simultaneous passes though the data, each pass comprising both a first filter and a second filter and said first and second filter parameters are based on the received data and the intersymbol interference is removed from said modified data in a nonlinear manner.