Systems and methods for equalizer correction
A method for equalizer correction in a communication network includes (a) obtaining raw equalizer coefficients in a frequency domain, (b) removing time delay from the raw equalizer coefficients to generate corrected equalizer coefficients in a time domain such that a direct current (DC) corrected equalizer coefficient of the corrected equalizer coefficients has a phase of zero, and (c) converting the corrected equalizer coefficients from the time domain to the frequency domain.
1. A method for equalizer correction in a communication network, comprising:
obtaining raw equalizer coefficients in a frequency domain;
removing time delay from the raw equalizer coefficients to generate corrected equalizer coefficients in a time domain such that a direct current (DC) corrected equalizer coefficient of the corrected equalizer coefficients has a phase of zero; and
converting the corrected equalizer coefficients from the time domain to the frequency domain.
2. The method of claim 1 , wherein removing time delay from the raw equalizer coefficients to the generate corrected equalizer coefficients comprises:
removing linear delay from the raw equalizer coefficients in the frequency domain to generate first equalizer coefficients;
converting the first equalizer coefficients from the frequency domain to the time domain to generate second equalizer coefficients; and
rotating phase of all second equalizer coefficients by a phase of a DC second equalizer coefficient, to generate the corrected equalizer coefficients.
3. The method of claim 2 , further comprising estimating the linear delay from a change in phase of the raw equalizer coefficients with respect to frequency.
4. The method of claim 3 , further comprising excluding one or more portions of the raw equalizer coefficients that are affected by group delay, when estimating the linear delay from the change in phase of the raw equalizer coefficients with respect to frequency.
5. The method of claim 2 , further comprising determining the phase of the DC second equalizer coefficient.
6. The method of claim 1 , further comprising normalizing the corrected equalizer coefficients.
7. The method of claim 1 , wherein the raw equalizer coefficients represent one of a channel response of a communication link and an inverse of a channel response of a communication link.
8. The method of claim 1 , wherein the raw equalizer coefficients are one of pre-distortion equalizer coefficients or post-distortion equalizer coefficients.
9. The method of claim 1 , further comprising determining a linear distortion of a communication link at least partially based on a relationship between (a) magnitude of the DC corrected equalizer coefficient and (b) total magnitude of all corrected equalizer coefficients.
10. The method of claim 1 , further comprising determining group delay of a communication link from the corrected equalizer coefficients.
11. The method of claim 1 , further comprising determining a location of an impairment in a communication link from the corrected equalizer coefficients.