Cognitive and Universal Impulse Noise Protection

• US 20090177938A1
• Filed: 01/05/2009
• Published: 07/09/2009
• Est. Priority Date: 01/03/2008
• Status: Active Grant

• Current Assignee: Ikanos Communications Incorporated (Qualcomm, Inc.)
• Original Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Inventors: Pons, Julien D., Sorbara, Massimo, Duvaut, Patrick, Zheng, Yue-Peng
• Granted Patent: US 8,112,687 B2
• Time in Patent Office: Days
• US Class Current: 714/751
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0019 in which mode-switching is based on a statistical approach
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

Impulse noise from nearby or intense electrical sources can disrupt communications over digital subscriber lines. There are many methods to deal with errors produced by impulse noise sources. Forward error correction (FEC) codes such as Reed Solomon coding along with scrambling and interleaving are used to correct small errors. However, for larger errors, retransmission is favored. Retransmission can be applied at the Discrete Multi-tone symbol level thus eliminating the need to insert sequence identification into data transmission units, furthermore retransmission can also be employed to exploit the error correcting capabilities of the FEC codes. Finally, an impulse noise protection system can exploit impulse noise statistics to configure the redundancy in the FEC codes and to enable the use of blanking. Exemplary embodiments of systems described can cooperatively use impulse noise statistics to utilize retransmission, FEC and blanking to mitigate the effects of impulse noise.

Claims

1. A method of communication comprising:

encoding first data by a forward error correction (FEC) encoder having an error correction capability (ECC) into a first transmission packet;

storing the first transmission packet or the first data into a retransmission memory;

receiving retransmission information relating to a second transmission packet from a receiver;

analyzing the retransmission information;

determining whether a retransmission of the second transmission packet comprising encoded second data is required based on the retransmission information and the ECC; and

if a retransmission is required,

either retrieving from the retransmission memory the second transmission packet or retrieving from the retransmission memory the second data and encoding the second data by the FEC into the second transmission packet; and

retransmitting the second transmission packet.

2. The method of claim 1, wherein retransmission information comprises received status information for each transmission packet.

3. The method of claim 1, wherein the transmission packet is a Discrete Multi-tone (DMT) symbol.

4. The method of claim 1, further comprising:

receiving impulse noise information relating to a receiver from an impulse noise monitoring/analysis module;

determining whether there is a change in repetitive electrical impulse noise (REIN) sources based on the impulse noise information and whether the impulse noise information includes impulse length and inter-arrival time (IAT) information; and

in response to determining whether there is a change,

determining whether there is any detailed timing information in the impulse noise information for the change in REIN sources;

adjusting blanking timing information based on the detailed timing information and transmitting the blanking information to the receiver, if detailed timing information is in the impulse noise information; and

determining a required ECC is based on the change in REIN sources not accounted for by the blanking timing information, adjusting the FEC encoder and an FEC decoder in the receiver if the ECC is less than the required ECC.

5. The method of claim 4, wherein the FEC encoder is a Reed Solomon encoder and interleaver and the FEC decoder is a Reed Solomon decoder and de-interleaver, wherein the ECC is based on a Reed Solomon redundancy and/or an interleaving depth wherein adjusting the FEC encoder and the FEC decoder comprises:

changing the redundancy by initiating a seamless rate adjustment; and

/or

changing the interleaving depth by using an interleaving depth change message.

6. A method of communication comprising:

receiving from a transmitter a transmission packet encoded by an FEC encoder having an ECC;

determining whether the transmission packet is received in error; and

if the transmission packet is received in error,

determining if the ECC can tolerate another transmission packet error; and

signaling a retransmission of the transmission packet to the transmitter, if the ECC cannot tolerate another transmission packet error.

7. The method of claim 6 further comprising:

if the transmission packet is received in error, providing the transmission packet to an FEC decoder, if the ECC can tolerate another transmission packet error; and

if the transmission packet is not received in error providing the transmission packet to the FEC decoder.

8. The method of claim 6, wherein determining whether the transmission packet is received in error comprises:

receiving from an impulse noise monitoring/analysis module impulse noise information relating to the transmission packet; and

determining whether the transmission packet is corrupted based on the impulse noise information relating to said transmission packet.

9. The method of claim 6, wherein the transmission packet is a DMT symbol.

10. The method of claim 6, further comprising:

receiving impulse noise information from an impulse noise monitoring/analysis module;

determining whether there is a change in REIN sources based on the impulse noise information and whether the impulse noise information includes impulse length and IAT information; and

in response to determining whether there is a change,

determining whether there is any detailed timing information in the impulse noise information for the change in REIN sources;

adjusting blanking timing information based on the detailed timing information and transmitting the blanking information to the transmitter, if detailed timing information is in the impulse noise information; and

determining a required ECC is based on the change in REIN sources not accounted for by the blanking timing information, adjusting the FEC encoder and the FEC decoder if the ECC is less than the required ECC.

11. The method of claim 10, wherein, the FEC encoder is a Reed Solomon encoder and interleaver and the FEC decoder is a Reed Solomon decoder and de-interleaver, wherein the ECC is based on a Reed Solomon redundancy and/or an interleaving depth, wherein adjusting the FEC encoder and the FEC decoder comprises:

changing the redundancy by initiating a seamless rate adjustment; and

/or

changing the interleaving depth by using an interleaving depth change message.

12. A transmitter comprising:

an FEC encoder having an ECC;

a retransmission memory;

a processor; and

a program memory comprising instructions,

said instructions causing the processor to;

instruct the FEC to encode first data into a first transmission packet;

store the first transmission packet or the first data into the retransmission memory;

receive retransmission information relating to a second transmission packet from a receiver;

analyze the retransmission information;

determine whether a retransmission of the second transmission packet is required based on the retransmission information and the ECC; and

either retrieve from the retransmission memory the second transmission packet or retrieve from the retransmission memory the second data and encode the second data by the FEC into the second transmission packet if a retransmission is required; and

retransmit the second transmission packet if a retransmission is required.

13. The transmitter of claim 12, wherein retransmission information comprises received status information for each transmission packet.

14. The transmitter of claim 13, wherein the status information has a received time and each transmission packet retransmitted is determined based on a predetermined time offset from the received time.

15. The transmitter of claim 12, wherein the transmission packet is a DMT symbol.

16. The transmitter of claim 12, wherein the instructions further cause the processor to:

receive impulse noise information relating to a receiver from an impulse noise monitoring/analysis module;

determine whether there is a change in REIN sources based on the impulse noise information and whether the impulse noise information includes impulse length and IAT information; and

in response to determining whether there is a change,

determine whether there is any detailed timing information in the impulse noise information for the change in REIN sources;

adjust blanking timing information based on the detailed timing information and transmitting the blanking information to the receiver, if detailed timing information is in the impulse noise information; and

determine a required ECC is based on the change in REIN sources not accounted for by the blanking timing information, and adjust the FEC encoder and an FEC decoder in the receiver if the ECC is less than the required ECC.

17. The transmitter of claim 16, wherein determining the required ECC is further based on a margin to account for errors not caused by impulse noise.

18. The transmitter of claim 17, wherein the ECC is adjusted to the margin.

19. The transmitter of claim 16, wherein the FEC encoder is a Reed Solomon encoder and interleaver and the FEC decoder is a Reed Solomon decoder and de-interleaver, wherein the ECC is based on a Reed Solomon redundancy and/or an interleaving depth wherein adjusting the FEC encoder and the FEC decoder comprises:

changing the redundancy by initiating a seamless rate adjustment; and

/or changing the interleaving depth by using an interleaving depth change message.

20. A receiver comprising:

an FEC decoder;

a processor; and

a program memory comprising instructions,

said instructions causing the processor to;

receive from a transmitter a transmission packet encoded by a FEC encoder having an ECC;

determine whether the transmission packet is received in error; and

if the transmission packet is received in error,

determine if the ECC can tolerate another transmission packet error; and

signal a retransmission of the transmission packet to the transmitter, if the ECC cannot tolerate another transmission packet error.

21. The receiver of claim 20, wherein the instructions further cause the processor to:

if the transmission packet is received in error, provide the transmission packet to the FEC decoder, if the ECC can tolerate another transmission packet error; and

if the transmission packet is not received in error provide the transmission packet to the FEC decoder.

22. The receiver of claim 20, wherein the processor signals a retransmission by status information for each transmission packet, wherein the status information conveys a bad state if the transmission packet is corrupted and conveys a good state if the transmission packet is not corrupted.

23. The receiver of claim 20, wherein the instructions further cause the processor to:

receive a retransmission of a corrupt transmission packet; and

provide the retransmission to the FEC decoder, wherein the retransmission of the corrupt transmission packet is received a fixed time period after a retransmission request of a corrupt transmission packet is signaled.

24. The receiver of claim 20, wherein the processor determines whether the transmission packet is received in error by

receiving from an impulse noise monitoring/analysis module impulse noise information relating to the transmission packet;

and

determining whether the transmission packet is corrupted based on the impulse noise information relating to said transmission packet.

25. The receiver of claim 20, wherein the transmission packet is a DMT symbol.

26. The receiver of claim 20, wherein the instructions further cause the processor to ignore transmission packets during a blanking period.

27. The receiver of claim 20, wherein the instructions further cause the processor to:

receive impulse noise information from an impulse noise monitoring/analysis module;

determine whether there is a change in REIN sources based on the impulse noise information and whether the impulse noise information includes impulse length and IAT information; and

if there is a change,

determine whether there is any detailed timing information in the impulse noise information for the change in REIN sources;

adjust blanking timing information based on the detailed timing information and transmitting the blanking information to the transmitter, if detailed timing information is in the impulse noise information; and

determine a required ECC is based on the change in REIN sources not accounted for by the blanking timing information, adjusting the forward error correction encoder if the ECC is less than the required ECC.

28. The receiver of claim 27, wherein determining the required ECC is further based on a margin to account for errors not caused by impulse noise.

29. The receiver of claim 28, wherein the ECC is adjusted to the margin.

30. The receiver of claim 27, wherein the FEC encoder is a Reed Solomon encoder and interleaver and the FEC decoder is a Reed Solomon decoder and de-interleaver, wherein the ECC is based on a Reed Solomon redundancy and/or an interleaving depth wherein adjusting the FEC encoder and the FEC decoder comprises:

changing the redundancy by initiating a seamless rate adjustment and/or

changing the interleaving depth by using an interleaving depth change message.

31. The receiver of claim 30, wherein the receiver comprises the impulse noise monitoring/analysis module.