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US 2006/0039460 A1Published application
Adaptive equalizer
AssigneeZenith Electronics Corporation
InventorsMark Fimoff, Sreenivasa Nerayanuru, Sedar Ozen
Life of this patent
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Abstract
A channel impulse response is determined from a cross-correlation of a received training sequence and a stored version of the transmitted training sequence. The channel impulse response is iteratively cleansed of noise caused by the finiteness of the cross-correlation. Initial values of the tap weights for the taps of an equalizer such as a decision feedback equalizer may be determined based on the cleansed channel impulse response.
Claims24
A method for estimating a channel comprising:
- cross-correlating a known training sequence with received training data to produce a cross-correlation vector, wherein the cross-correlation vector is characterized by a noise component resulting from the finiteness of the cross-correlation;
- calculating a threshold value that is a fraction of the strength of the main peak of the cross-correlation vector;
- and,
- iteratively selecting, scaling, and subtracting correction vectors from a set of correction vectors based on the known training sequence, wherein the correction vectors in the set of pre-stored correction vectors are related to shifted versions of the noise component, and wherein such selections are based on cross-correlation peaks that are above the threshold value to produce a succession of channel estimates of improved accuracy.
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A method for estimating a channel comprising:
- (a) cross-correlating a known training sequence with received training data to produce a cross-correlation vector, wherein the cross-correlation vector is characterized by a noise component resulting from the finiteness of the cross-correlation;
- (b) calculating a threshold value that is a fraction of the strength of the main peak of the cross-correlation vector;
- (c) selecting and scaling in one step a subset of correction vectors from a set of pre-stored correction vectors based on the known training sequence, wherein the subset of correction vectors is selected based on the threshold value;
- (d) simultaneously subtracting all of the selected and scaled correction vectors from the cross-correlation vector to produce a new channel estimate;
- (e) reducing the threshold value by a fixed factor;
- and,
- (f) iteratively repeating (c)-(e) until the 2-norm of the difference between the new channel estimate and a previous channel estimate is not greater than a given value.
4 more elements
Dependencies are inferred from the claim text.