Search engine for a receive equalizer
AssigneeBroadcom Corporation
InventorsAfshin Momtaz, Rajesh Satapathy, Chung-Jue Chen
Life of this patent
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Abstract
A search engine selects initial coefficients for a receive equalizer. The search engine may be incorporated into a communication receiver that includes a decision feedback equalizer and clock and data recovery circuit. Here, the search engine may initialize various adaptation loops that may control the operation of, for example, a decision feedback equalizer, a clock and data recovery circuit and a continuous time filter. The receiver may include an analog-to-digital converter that is used to generate soft decision data for some of the adaptation loops.
Claims22
A method of identifying a coefficient for a receive equalizer comprising:
- identifying which coefficient combinations from a first group or, if none in the first group, a second group of sets of coefficients that enable a clock recovery circuit to lock to a received signal;
- calculating an error value associated with a received signal when the at least one equalizer component is configured with each of the identified sets of coefficients;
- and
- selecting, based on the error value calculation, one of the identified sets of coefficients.
A communications system comprising:
- a filter for filtering a received signal in accordance with at least one coefficient generated by a first adaptation loop;
- an equalizer adapted to reduce channel related distortion in the received signal in accordance with at least one equalizer coefficient generated by a second adaptation loop;
- a clock recovery circuit adapted to recover a clock signal from the received signal;
- and
- a search engine configured to select an initial set of coefficients for at least one of the adaptation loops from at least a first and a second group of sets of coefficients, the search engine configured to:
- identify which sets of combinations from a first group or, if none in the first group, a second group of sets of coefficients that enable the clock recovery circuit to lock;
- obtain an error value derived from the received signal when the at least one of the adaptation loops is configured with each of the identified sets of coefficients;
- and
- select, based on the error value calculation, one of the identified sets of coefficients as the initial set of coefficients.
An apparatus comprising:
- means for identifying coefficient combinations from a first one of a plurality of groups that enable a clock recovery circuit to lock to a received signal;
- means for, if the clock recovery circuit does not acquire lock for any of the coefficient combinations from the first set, identifying coefficient combinations from a subsequent one of the groups that enable the clock recovery circuit to lock to the received signal;
- means for calculating an error value associated with the received signal when the equalizer components are configured with each of the identified coefficient combinations;
- and
- means for selecting, based on the error value calculation, one of the identified coefficient combinations.
Dependencies are inferred from the claim text.