US 6,188,721 B1 · System and method for adaptive equalization of a waveform independent of absolute waveform peak value

Abstract

An improved adaptive equalizer providing the proper amount of equalization to restore the missing frequency components of a received and underequalized waveform. The invention'equalization gain or pulse counting feature can be set at various levels by digitally programming the control logic of the invention. Additionally, the digital control features of the invention permit higher accuracy in determining required equalizations for waveforms and avoid variations, such as temperature process variations, present in analog systems. The invention permits higher accuracy in determining required equalizations for waveforms. The invention finds, holds, and updates the average low frequency peak of the incoming signal in a highly digital manner. Since peak information is digitally held, it is not subject to the data dependent drifts inherent in analog peak detectors. The invention equalizes the signal by continually digitally comparing the high frequency peaks of the incoming transitions to the average low frequency peak and either adding or subtracting frequency components until the high and average low frequency peaks are close to one another. The amount of frequency compensation is a measure of the equalization and is digitally held by the invention and continually updated.

Claims10

Dependent claims

A method for adaptive equalization of a waveform, comprising the steps of:

(1) initiating a peak training mode;
(2) initiating an adaptive equalizer training mode at the termination of peak training mode;
and
(3) initiating an adaptive equalizer mode at the termination of said adaptive equalizer training mode;
wherein said step for initiating the adaptive equalizer mode comprises the steps of:
(a) computing a moving-average of peak voltage levels of low-pass filtered high pulses;
(b) measuring the peak voltage level of a high pulse;
(c) subtracting the result of step (a) from the result of step (b);
(d) using the result of step (b) to compute an updated moving-average of the peak voltage levels of the low-pass filtered high pulses;
(e) computing a moving-average of peak voltage levels of low-pass filtered low pulses;
(f) measuring the peak voltage level of a low pulse;
(g) subtracting the result of step (e) from the result of step (f);
(h) using the result of step (f) to compute an updated moving-average of the peak voltage levels of the low-pass filtered low pulses;
and
(i) using the subtraction results of step (g) and step (c) to provide the required equalization of the waveform.

12 more elements

Dependencies are inferred from the claim text.

System and method for adaptive equalization of a waveform independent of absolute waveform peak value

Life of this patent

System and method for adaptive equalization of a waveform independent of absolute waveform peak value

Life of this patent

Abstract

Claims10