Fast Dynamic Noise Detection/Adaptation System For DSL Modems

• US 20070258527A1
• Filed: 05/07/2007
• Published: 11/08/2007
• Est. Priority Date: 05/08/2006
• Status: Abandoned Application

• Current Assignee: Ikanos Communications Incorporated (Qualcomm, Inc.)
• Original Assignee: Centillium Communications Incorporated (Transwitch Corporation)
• Inventors: Simileysky, Victor, Fazlollahi, Amir
• Application Number:
  US11/745,333
• Publication Number:
  US 20070258527A1
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/206 for modulated signals
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

A systems and a method for a DMT-based DSL modem to detect time-varying noise dynamically during transmission and adapt to its rapid changes promptly by increasing or reducing data rate while maintaining the transmission and utilizing maximum channel capacity. A DMT-based modem reserves a first set of sub-channels to detect and measure the time-varying noise. The modem further provides reliable communications for control messages through a second set of sub-channels. The control messages are used to adjust communication to adapt to the new noise conditions over all sub-channels.

Claims

1. A method for detecting and adapting to time-varying noise in a DMT-based broadband communication system, comprising:

selecting a set of monitoring sub-channels, the number of monitoring sub-channels is substantially smaller than total number of sub-channels in the system, the noise margins of monitoring sub-channels are higher than the noise margins of non-monitoring sub-channels;

detecting the time-varying noise in the set of monitoring sub-channels;

measuring the time-varying noise in each of the set of monitoring sub-channels;

estimating the time-varying noise in the non-monitoring sub-channels; and

sending a control message to adjust communication in the system responding to the time-varying noise.

2. The method of claim 1, wherein selecting the set of monitoring sub-channels comprises selecting monitoring sub-channels located in spectrums for services that comprise at least one selected from a group consisting of:

DSL, ADSL, VDSL, HDSL, and ISDN.

3. The method of claim 1, wherein selecting the set of monitoring sub-channels comprises selecting monitoring sub-channels located in spectrums for services provided in nearby communication lines.

4. The method of claim 1, further comprising:

reselecting the set of monitoring sub-channels based on the noise.

5. The method of claim 1, further comprising:

determining a nature of a source of the detected noise based on the time-varying noise in two or more monitoring sub-channel in the set of monitoring sub-channels.

6. The method of claim 1, wherein sending the control message further comprises sending the control message through a reliable communication channel.

7. The method of claim 6, wherein the reliable communication channel comprises one or more monitoring sub-channels.

8. The method of claim 1, wherein sending a control message comprises sending a control message to adjust data rate in the non-monitoring sub-channels responding to the time varying noise.

9. A network element in a DMT-based broadband communication system, comprising:

a chipset; and

a memory unit comprising a persistent memory that contains microcode for execution by the chipset to cause the chipset to perform the operations,

selecting a set of monitoring sub-channels, the number of monitoring sub-channels is substantially smaller than total number of sub-channels in the system, the noise margins of monitoring sub-channels are higher than the noise margins of non-monitoring sub-channels,

detecting time-varying noise in the set of monitoring sub-channels,

measuring the time-varying noise in each of the set of monitoring sub-channels,

estimating the time-varying noise in the non-monitoring sub-channels, and

sending a control message to adjust communication in the system responding to the time-varying noise.

10. A DMT-based broadband communication system, comprising:

a first network element, wherein the first network element transmits data to a second network element through a set of downstream sub-channels and receives data from the second network element through a first set of upstream sub-channels, wherein the first network element detects and measures time-varying noise through a second set of upstream sub-channels from the first set of upstream sub-channels, the number of the upstream sub-channels in the second set of upstream sub-channels being substantially smaller than the number of the upstream sub-channels in the first set of upstream sub-channels, the noise margin of the upstream sub-channels in the second set of upstream sub-channels being higher than the rest upstream sub-channels in the first set of upstream sub-channels; and

the second network element, wherein the second network element detects and measures time-varying noise through a second set of downstream sub-channels from the first set of downstream sub-channels, the number of the downstream sub-channels in the second set of downstream sub-channels being substantially smaller than the number of the downstream sub-channels in the first set of downstream sub-channels, the noise margin of the downstream sub-channels in the second set of downstream sub-channels being higher than the rest downstream sub-channels in the first set of downstream sub-channels.