Patent Number: 6,167,082

Title: Adaptive equalizers and methods for carrying out equalization with a precoded transmitter

Abstract: Adaptive equalization methods and adaptive equalizers used with precoded systems dominated by intersymbol interference (ISI) monitor the output of a DFE and compare it to a reference for updating a precoder in response to the comparison. To accomplish this, an adaptive equalizer includes a feed forward equalizer receiving a signal from a communication channel, the feed forward equalizer equalizing variations in pre-cursor intersymbol interference resulting from changes in characteristics of the channel and providing an output signal to an error correction decoder, a decision circuit, coupled to the feed forward equalizer, for generating error vectors in response to the output signal of the feed forward equalizer and a decision feedback equalizer, coupled to the decision circuit, the decision feedback equalizer monitoring the pre-cursor intersymbol interference of the channel, determining when the transmitter coefficients to the precoder warrant updating, and generating a signal indicating that an update to the transmitter coefficients to the precoder is warranted. The adaptive equalizer farther includes a comparison circuit, the comparison circuit receiving an output from the decision feedback equalizer and comparing the output from the decision feedback equalizer to a reference, the comparison circuit generating the signal indicating that an update to the transmitter coefficients to the precoder is warranted in response to the comparison.

Inventors: Ling; Stanley K. (Sacramento, CA), An; Ping (Sacramento, CA), Takatori; Hiroshi (Sacramento, CA)

Assignee: Level One Communications, Inc.

International Classification: H04L 25/03 (20060101); H03K 005/159 (); H03H 005/00 ()

Expiration Date: 12/26/2017