Self-calibrating continuous-time equalization

摘要

Embodiments of the invention comprise a continuous-time equalizer for reducing ISI in data received from a communication channel, and methods and circuitry for tuning or calibrating that equalizer. Selected coefficients for a transfer function of the equalizer circuit are fixed, while other coefficients are tuned by an adaptive algorithm. The adaptive algorithm minimizes errors associated with the tunable coefficients based on one or more training signals sent by the transmitter and received by the equalizer circuit at the receiver. The training signals allow for a variety of error terms to be calculated, from which the tunable coefficients are updated so as to iteratively minimize the error terms and simultaneously tune the equalizer to more accurately compensate for the degrading effects of the channel.

主权项

1. A method for tuning an equalizer coupled to a channel, the channel having a frequency response, comprising:
receiving at least one training signal including two pulses at the equalizer, wherein the two pulses of the at least one training signal are sent through the channel in consecutive intervals; assessing the at least one training signal to respectively derive two cursor values at centers of the consecutive intervals and to deduce at least one error term, wherein the at least one error term comprises a difference between the two cursor values indicative of asymmetry in the received at least one training signal; tuning the equalizer using the at least one error term; and repeating the receiving, the assessing, and the tuning to reduce the at least one error term.