Patent ID: 7415067

Claim:
A Fixed-Delay Tree Search with Decision Feedback (FDTS/DF) equalizer, comprising: a feed-forward filter receiving and filtering a sampled signal; a feed-back filter filtering a restored data; a subtractor subtracting signals respectively filtered by the feed-forward filter and the feed-back filter; and a detector receiving the subtracted signal and detecting a data using an absolute value calculation, wherein the detector comprises: a plurality of branch metric calculating units obtaining an error between the subtracted signal and a reference signal, wherein the reference signal is time-variant and is determined by the feed-back filter and by an original data detected by the detector; an adder adding the values outputted from the plurality of branch metric calculating units; a path metric memory storing the added value; a minimum value calculating unit calculating a minimum value of the accumulated values; and a comparator comparing the minimum values and outputting a most minimum value, and wherein the plurality of branch metric calculating units comprise: a plurality of absolute value calculating units obtaining an absolute value of a difference between the subtracted signal and the reference signal; a demultiplexer demultiplexing the absolute value outputted from the plurality of absolute value calculating units; and an adding unit adding the demultiplexed value outputted from the demultiplexer and a path metric value prior to a one period of sampling time.