Method and System for Adaptive Tone Cancellation for Mitigating the Effects of Electromagnetic Interference
Aspects of a method and system for adaptive tone cancellation for mitigating the effects of interference are provided. In this regard, an Ethernet PHY may receive one or more signals via a corresponding one or more physical channels and generate one or more estimate signals, each of which approximates interference present in a corresponding one of the received signals. The Ethernet PHY may subtract each one of the estimate signals from a corresponding one of the received signals. The subtracting may occur at the input of one or more slicers in the Ethernet PHY. The received signals may be processed via one or more equalizers in the Ethernet PHY. A decision output of a slicer in the Ethernet PHY may be subtracted from one of the the one or more received signals, and a signal resulting from the subtraction may be utilized to generate the one or more estimate signals.
1 . A method for communications, the method comprising:
in an Ethernet PHY:
receiving one or more signals via a corresponding one or more physical channels;
generating a plurality of estimate signals, each of which approximates interference present in a corresponding one of the one or more received signals;
generating, in the Ethernet PHY, a pair of phase-quadrature signals having a frequency that tracks a frequency of the interference, wherein one or more adaptive filters of the Ethernet PHY utilizes the generated pair of phase-quadrature signals for the generation of the plurality of estimate signals; and
subtracting each one of the plurality of estimate signals from a corresponding one of the received one or more signals, wherein the subtracting occurs at an input of one or more slicers in the Ethernet PHY.
2 . The method according to claim 1 , comprising processing, in the Ethernet PHY, the one or more received signals via a corresponding one or more equalizers.
3 . The method according to claim 1 , comprising:
receiving, in the Ethernet PHY, a common mode signal from a common mode sensor coupled to one of the physical channels; and
generating the plurality of estimate signals utilizing the common mode signal.
4 . The method according to claim 1 , comprising:
processing, in the Ethernet PHY, the one or more received signals via a corresponding one or more equalizers;
subtracting, at an output of a corresponding one of the one or more equalizers, a decision output of one of the slicers in the Ethernet PHY from one of the one or more received signals; and
generating the plurality of estimate signals utilizing a signal resulting from the subtracting of the decision output.
5 . The method according to claim 1 , comprising generating the plurality of estimate signals utilizing one signal selected from signals comprising:
a signal output by an equalizer of the Ethernet PHY;
a signal resulting from a subtraction of a decision output of one of the slicers from the signal output by the equalizer; and
a signal output by a common mode sense circuit coupled to one of the physical channels.
6 . The method according to claim 5 , comprising selecting the signal based on a strength of the interference.
7 . The method according to claim 1 , comprising selecting, in the Ethernet PHY, one of a decision output of one of the slicers of the Ethernet PHY and an error output of the one of the slicers for the generation of the plurality of estimate signals.
8 . The method according to claim 7 , comprising selecting the one of the decision output and the error output based on a strength of the interference.
9 . The method according to claim 7 , wherein:
an adaptive filter of the Ethernet PHY utilizes the selected one of the decision output; and
the error output for the generation of the plurality of estimate signals.
10 . A system for communications, the system comprising:
one or more circuits or processors for use in an Ethernet PHY, wherein the one or more circuits or processors comprise one or more slicers, one or more adaptive filters, and the one or more circuits or processors are operable to:
receive one or more signals via a corresponding one or more physical channels;
generate one or more estimate signals, each of which approximates interference present in a corresponding one of the received signals;
generate a pair of phase-quadrature signals having a frequency that tracks a frequency of the interference;
utilize the pair of phase-quadrature signals for the generation of the one or more estimate signals; and
subtract each one of the estimate signals from a corresponding one of the received signals, wherein the subtracting occurs at an input of the one or more slicers.
11 . The system according to claim 10 , wherein:
the one or more circuits or processors comprise one or more equalizers; and
each of the one or more received signals is processed via a corresponding one of the one or more equalizers.
12 . The system according to claim 10 , wherein the one or more circuits or processors are operable to:
receive a common mode signal from a common mode sensor coupled to one of the physical channels; and
generate the one or more estimate signals utilizing the common mode signal.
13 . The system according to claim 10 , wherein:
the one or more circuits or processors comprise one or more equalizers and;
each of the one or more received signals is processed via a corresponding one of the one or more equalizers;
the one or more circuits or processors are operable to subtract, at an output of a corresponding one of the one or more equalizers, a decision output of one of the one or more slicers from one of the one or more received signals; and
the one or more circuits or processors are operable to generate the one or more estimate signals utilizing a signal resulting from the subtracting of the decision output.
14 . The system according to claim 10 , wherein:
the one or more circuits or processors comprise an equalizer and a common mode sense circuit; and
the one or more circuits or processors are operable to generate the one or more estimate signals utilizing one signal selected from signals comprising:
a signal output by the equalizer of the Ethernet PHY,
a signal resulting from a subtraction of a decision output of one of the one or more slicers from the signal output by the equalizer, and
a signal output by the common mode sense circuit coupled to one of the physical channels.
15 . The system according to claim 14 , wherein the signal is selected based on a strength of the interference.
16 . The system according to claim 10 , wherein the one or more circuits or processors select one of a decision output of one of the one or more slicers and an error output of one of the one or more slicers for the generation the one or more estimate signals.
17 . The system according to claim 16 , wherein the one or more circuits or processors are operable to select the one of the decision output and the error output based on a strength of the interference.
18 . The system according to claim 16 , wherein:
the adaptive filter utilizes the selected one of the decision output; and
the error output for generating one of the one or more estimate signals.
19 . A non-transitory computer readable medium having processor instructions for communications, that when executed by the processor, cause the processor to:
generate a plurality of estimate signals, each of which approximates interference present in a corresponding one of one or more received signals on one or more physical channels;
generate a pair of phase-quadrature signals having a frequency that tracks a frequency of the interference, wherein one or more adaptive filters of the Ethernet PHY utilizes the generated pair of phase-quadrature signals for the generation of the plurality of estimate signals; and
subtract each one of the plurality of estimate signals from a corresponding one of the received one or more signals, wherein the subtracting occurs at an input of one or more slicers in the Ethernet PHY.
20 . The computer readable medium of claim 19 , the processor further caused to select one of a decision output of one of the one or more slicers and an error output of one of the one or more slicers for the generation the one or more estimate signals based on a strength of the interference.