Patent ID: 8279916

Claim:
A method of equalizing inter-symbol interference (ISI) in a received signal corresponding to a transmitted signal carried over a channel, comprising: grouping points of a constellation associated with the transmitted signal into a plurality of subsets, at least two adjacent ones of the subsets having one or more common constellation points so that the at least two adjacent subsets overlap; determining a centroid-based value for each of the subsets of constellation points; grouping the centroid-based values into one or more sets for input to an equalizer having a plurality of stages, wherein a first stage of the equalizer localizes the search for a final symbol decision by: demodulating the received signal using the set of centroid-based values input to the first stage to generate a sequence of symbols output by the first stage; generating a re-modulated signal associated with the first stage as a function of the sequence of symbols generated by the first stage and the channel over which the transmitted signal is carried; removing the re-modulated signal associated with the first stage from the transmitted signal to generate a modified signal for input to the stage immediately following the first stage; and equalizing the ISI using the equalizer, each of the stages except for a last one of the stages localizing a search for the final symbol decision using the set of centroid-based values input to or selected by the stage as constellation points and the last stage determining the final symbol decision using the subset of constellation points input to or selected by the last stage, wherein the last stage of the equalizer determines the final symbol decision by: demodulating a modified version of the received signal output by the stage immediately preceding the last stage using the subset of constellation points input to or selected by the last stage to generate a sequence of symbols associated with the last stage; and summing each of the sequences of symbols generated by the different stages to determine the final symbol decision.