Method and system for interference cancellation
View Patent ↗Aspects of a method and system for interference cancellation substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims. In this regard, a receiver may be operable to receive a differential signal via a differential channel, and to sense a common mode signal on the differential channel. A frequency range in which interference is present in the common mode signal may be determined. The differential signal and the common mode signal may be filtered to attenuate frequencies outside the determined frequency range. A phase and/or amplitude of the filtered common mode signal may be adjusted based on the filtered differential signal and the adjusted and filtered common mode signal may be subtracted from the received differential signal. The common mode signal may be sensed via a pair of resistors coupled to the differential channel.
1. A method for communications, comprising:
sensing a common mode signal;
determining a frequency range in which interference is present in said common mode signal;
adjusting a frequency response of an adaptive filter according to said determined frequency range of said interference in said common mode signal; configuring a responsive filter based on the adjusted frequency response; filtering, with said responsive filter,
a differential signal to generate a filtered differential signal that is without said interference; and
generating a representative signal of the interference in said common mode signal based on the filtered differential signal and an adjusted common mode signal.
2. The method according to claim 1 , wherein
determining said frequency range in which interference is present in said common mode signal comprises converging on and locking to a narrowband interference frequency of said common mode signal.
3. The method according to claim 2 , further comprising
determining whether to enable or disable an interference cancellation mode based on whether said converging converges on and locks to said narrowband interference frequency of said common mode signal.
4. The method according to claim 1 , further comprising
generating the adjusted common mode signal by adjusting at least one of a phase and an amplitude of said common mode signal based on said filtered differential signal.
5. The method according to claim 4 , wherein
adjusting at least one of said phase and said amplitude of said common mode signal comprises reducing a difference between said filtered differential signal and said adjusted common mode signal.
6. The method according to claim 4 , further comprising
combining said filtered differential signal and said adjusted common mode signal.
7. The method according to claim 1 , further comprising
removing interference in the differential signal by subtracting the representative signal from the differential signal.
8. A system for communications, comprising:
a common mode sensor that senses a common mode signal;
a line enhancer that converges on a frequency in which interference is present in said common mode signal; and circuitry that adjusts a frequency response of the line enhancer according to a frequency range of said interference in said common mode signal, configures a responsive filter based on the adjusted frequency response, filters, with said responsive filter, a differential signal to generate a filtered differential signal that is without said interference, and
generates a representative signal of the interference in said common mode signal based on the filtered differential signal and an adjusted common mode signal.
9. The system according to claim 8 , wherein
said line enhancer automatically converges on and locks to a narrowband interference frequency of said common mode signal.
10. The system according to claim 8 , wherein the circuitry adjusts, with an adaptive filter, at least one of a phase and an amplitude of said common mode signal based on said filtered differential signal, to provide the adjusted common mode signal.
11. The system according to claim 10 , wherein
said circuitry reduces, with said adaptive filter, a difference between said filtered differential signal and said adjusted common mode signal.
12. The system according to claim 10 , wherein the circuitry combines said filtered differential signal and said adjusted common mode signal.
13. The system according to claim 8 , further comprising:
a filter bank; and
a multiplexer that selects between an output of said line enhancer and an output of said filter bank.
14. The system according to claim 13 , wherein
said multiplexer selects said filter bank when said line enhancer is unable to converge on said frequency in which interference is present in said common mode signal.
15. The system according to claim 14 , further comprising
a control unit that selects between a high-pass response and a low-pass response of said filter bank.
16. The system according to claim 8 , further comprising
a subtractor that removes interference in the differential signal by subtracting the representative signal from the differential signal.
17. A method for communications, comprising:
converging on a frequency in which interference is present in a common mode signal;
determining a frequency range in which interference is present in said common mode signal; adjusting a frequency response of an adaptive filter according to said determined frequency range of said interference in said common mode signal; configuring a responsive filter based on the adjusted frequency response; filtering, with said responsive filter,
a differential signal to generate a filtered differential signal that is without said interference;
enhancing said common mode signal to provide an enhanced common mode signal;
generating a representative signal of the interference in said common mode signal based on the filtered differential signal and the enhanced common mode signal; and
subtracting said representative signal from said differential signal.
18. The method according to claim 17 , wherein
converging on said frequency in which interference is present in said common mode signal comprises automatically converging on locking to a narrowband interference frequency of said common mode signal.
19. The method according to claim 17 , wherein
enhancing said common mode signal comprises adjusting at least one of a phase and an amplitude of said common mode signal based on said filtered differential signal.
20. The method according to claim 19 , wherein
adjusting at least one of said phase and said amplitude of said common mode signal comprises reducing a difference between said filtered differential signal and said enhanced common mode signal.