Systems and methods for compensating for impulse noise

• US 9,231,808 B1
• Filed: 06/21/2011
• Issued: 01/05/2016
• Est. Priority Date: 06/21/2011
• Status: Active Grant

• Current Assignee: ADTRAN Incorporated (ADTRAN Holdings, Inc.)
• Original Assignee: ADTRAN Incorporated (ADTRAN Holdings, Inc.)
• Inventors: Wilson, Arlynn Wayne, Goodson, Richard
• Primary Examiner(s): Vlahos, Sophia
• Application Number:
  US13/164,810
• Time in Patent Office: 1,659 Days
• Field of Search: 375/340, 375/346, 375/351, 375/347, 375/349, 375/350, 370/201, 379/416, 455/223, 455/295, 455/63.1, 455/67.13
• US Class Current: 1/1
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04B 3/30 Reducing interference caused by unbalanced currents in a normally balanced line
• CPC Class Codes: H04L 25/0276 Arrangements for coupling common mode signals
• CPC Class Codes: H04L 25/03006 Arrangements for removing intersymbol interference
• CPC Class Codes: H04L 25/085 Arrangements for reducing interference in line transmission systems, e.g. by differential transmission
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01

Abstract

Embodiments of the present disclosure generally pertain to systems and methods for compensating for impulse noise. A system in accordance with an exemplary embodiment of the present disclosure comprises a receiver coupled to a subscriber line. The receiver is configured to receive an encoded data signal via the subscriber line and separate the signal into a common mode (CM) signal and a differential mode (DM) signal. The receiver is further configured to detect impulse noise on the CM signal and mark corresponding sub-words of the DM signal affected by the detected impulse noise as erasures. The receiver then decodes the DM signal based on whether the sub-words are marked as erasures.

Claims

1. A receiver for compensating for impulse noise, comprising:

a signal component sampling element configured to receive a data signal from a subscriber line and to separate the data signal into a common mode signal and a differential mode signal;

an impulse noise detector configured to detect impulse noise in the common mode signal;

an erasure marking element configured to mark a sub-word of the differential mode signal as an erasure based on a detection of impulse noise in the common mode signal by the impulse noise detector, wherein the impulse noise detector is configured to compare the common mode signal to a threshold and to detect an occurrence of impulse noise based on a comparison of the common mode signal to the threshold, and wherein the impulse noise detector is configured to adaptively update the threshold; and

a decoder configured to decode the differential mode signal based on whether the sub-word is marked as an erasure by the erasure marking element.

2. A receiver for compensating for impulse noise, comprising:

a signal component sampling element configured to receive a data signal from a subscriber line and to separate the data signal into a common mode signal and a differential mode signal;

an impulse noise detector configured to detect impulse noise in the common mode signal;

an erasure marking element configured to mark a sub-word of the differential mode signal as an erasure based on a detection of impulse noise in the common mode signal by the impulse noise detector, wherein the impulse noise detector is configured to compare the common mode signal to a threshold and to detect an occurrence of impulse noise based on a comparison of the common mode signal to the threshold, and wherein the impulse noise detector is configured to establish the threshold based on the common mode signal; and

a decoder configured to decode the differential mode signal based on whether the sub-word is marked as an erasure by the erasure marking element.

3. The receiver of claim 2, further comprising:

a differential mode path having signal processing circuitry configured to process the differential mode signal, wherein the signal component sampling element and the erasure marking element are coupled to the signal processing circuitry of the differential mode path; and

a common mode path having signal processing circuitry configured to process the common mode signal, wherein the signal component sampling element and the impulse noise detector are coupled to the signal processing circuitry of the common path,

wherein a delay of the differential mode path from the signal component sampling element to the erasure marking element is substantially equal to a delay of the common mode path from the signal component sampling element to the impulse noise detector.

4. The receiver of claim 2, further comprising a de-interleaver coupled to the erasure marking element and the decoder, the de-interleaver configured to receive the differential mode signal, de-interleave code words of the differential mode signal, and transmit the differential mode signal to the decoder.

5. The receiver of claim 2, wherein the decoder is a forward error correction (FEC) decoder.

6. The receiver of claim 2, wherein the decoder is a trellis decoder.

7. The receiver of claim 2, wherein the receiver comprises a trellis decoder, and wherein the erasure marking element is configured to mark the sub-word as the erasure prior to the reception of the sub-word by the trellis decoder.

8. The receiver of claim 2, wherein the receiver comprises a trellis decoder, and wherein the erasure marking element is configured to mark the sub-word as the erasure after receiving the sub-word from the trellis decoder.

9. The receiver of claim 2, wherein the impulse noise detector is configured to transmit to the erasure marking element a signal based on the impulse noise detected in the common mode signal, the signal indicating whether the sub-word is corrupted, and wherein the erasure marking element is configured to mark the sub-word as the erasure based on the signal.

10. A receiver for compensating for impulse noise, comprising:

a signal component sampling element configured to receive a data signal from a subscriber line and to separate the data signal into a common mode signal and a differential mode signal;

an impulse noise detector configured to detect impulse noise in the common mode signal;

an erasure marking element configured to mark a sub-word of the differential mode signal as an erasure based on a detection of impulse noise in the common mode signal by the impulse noise detector; and

a decoder configured to decode the differential mode signal based on whether the sub-word is marked as an erasure by the erasure marking element,

wherein the impulse noise detector is configured to mark as an erasure a sub-word of a first tone of the differential mode signal based on a comparison of a first threshold to the common mode signal, wherein the impulse noise detector is configured to mark as an erasure a sub-word of a second tone of the differential mode signal based on a comparison of a second threshold to the common mode signal, and wherein a value of the first threshold is different than a value of the second threshold.

11. A method for compensating for impulse noise, comprising:

receiving a data signal;

separating the data signal into a common mode signal and a differential mode signal;

detecting impulse noise in the common mode signal, wherein the detecting comprises comparing the common mode signal to a threshold;

marking a sub-word of the differential mode signal as an erasure based on the detecting;

decoding the differential mode signal based on the marking; and

adaptively updating the threshold.

12. A method for compensating for impulse noise, comprising:

receiving a data signal;

separating the data signal into a common mode signal and a differential mode signal;

detecting impulse noise in the common mode signal, wherein the detecting comprises comparing the common mode signal to a threshold;

marking a sub-word of the differential mode signal as an erasure based on the detecting;

decoding the differential mode signal based on the marking; and

establishing the threshold based on the common mode signal.

13. The method of claim 12, further comprising de-interleaving the code word subsequent to the marking.

14. A receiver for compensating for impulse noise, comprising:

a signal component sampling element configured to receive a data signal from a subscriber line and to separate the data signal into a common mode signal and a differential mode signal;

an impulse noise detector configured to detect impulse noise in the common mode signal;

an erasure marking element configured to mark a sub-word of the differential mode signal as an erasure based on a detection of impulse noise in the common mode signal by the impulse noise detector;

a decoder configured to decode the differential mode signal based on whether the sub-word is marked as an erasure by the erasure marking element;

a differential mode path having signal processing circuitry configured to process the differential mode signal, wherein the signal component sampling element and the erasure marking element are coupled to the signal processing circuitry of the differential mode path; and

a common mode path having signal processing circuitry configured to process the common mode signal, wherein the signal component sampling element and the impulse noise detector are coupled to the signal processing circuitry of the common path,

wherein a delay of the differential mode path from the signal component sampling element to the erasure marking element is substantially equal to a delay of the common mode path from the signal component sampling element to the impulse noise detector, wherein the receiver comprises a trellis decoder, and wherein the erasure marking element is configured to mark the sub-word as the erasure after receiving the sub-word from the trellis decoder.

15. A method for compensating for impulse noise, comprising:

receiving a data signal;

separating the data signal into a common mode signal and a differential mode signal;

detecting impulse noise in the common mode signal;

marking a sub-word of the differential mode signal as an erasure based on the detecting; and

decoding the differential mode signal based on the marking,

wherein the sub-word corresponds to a first tone of the differential mode signal, wherein the detecting comprises comparing a first threshold to the sub-word corresponding to the first tone and comparing a second threshold to a sub-word corresponding to a second tone of the differential mode signal, wherein the marking is based on the comparing the first threshold, wherein the second threshold has a value different than a value of the first threshold, and wherein the method further comprises marking the sub-word corresponding to the second tone as an erasure based on the comparing the second threshold.