Method and apparatus for reducing cross-talk with reduced redundancies

• US 7,548,599 B2
• Filed: 06/30/2003
• Issued: 06/16/2009
• Est. Priority Date: 01/28/2003
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Agere Systems Incorporated (Broadcom, Inc.)
• Inventors: Azadet, Kameran
• Primary Examiner(s): Corrielus; Jean B
• Application Number:
  US10/610,334
• Publication Number:
  US 20040146002A1
• Time in Patent Office: 2,178 Days
• Field of Search: 375/350, 375/286, 375/290, 375/346, 370/201, 370/290, 370/286, 379/406.01, 379/406.08, 379/3
• US Class Current: 375/350
• CPC Class Codes: H04B 3/32 Reducing cross-talk, e.g. by compensating

Abstract

A method and apparatus are disclosed for reducing cross-talk in an unbalanced channel with a reduced number of redundancies. A cross-talk canceller is disclosed that uses a multi-dimensional finite impulse response (FIR) filter to process a received signal. Redundancies are reduced or even removed entirely by processing the signals received on each twisted pair in a vector form, using multi-dimensional finite impulse response filters. The signals received by a transceiver on each twisted pair are represented in a vector form so that the signals received on each twisted pair, and the cross-talk effect that each signal has on one another, can be performed collectively. A multi-dimensional cross-talk canceller processes a vector representation of the corresponding signals transmitted by the transceiver on each twisted pair. An adder sums the equalized vector representation of the signals received by the transceiver and the processed vector representation of the signals transmitted by the transceiver to generate an estimate of the received signal on each twisted pair.

Claims

1. A method for processing a received signal on each of a plurality of twisted pair, said method comprising the steps of:

generating a vector representation of said received signal, wherein said vector representation includes a component for each of said twisted pair; and

removing cross-talk from said received signal by applying said vector representation of said received signal to a multi-dimensional finite impulse response filter having matrix coefficients, wherein said removing step reduces redundant operations performed on said received signal relative to an implementation that employs a scalar representation of said received signal.

2. The method of claim 1, further comprising the step of equalizing said received signal.

3. The method of claim 1, wherein said removing step further comprises the step of removing near-end crosstalk that results from a signal on one twisted pair interfering with a signal on another twisted pair.

4. The method of claim 1, wherein said removing step further comprises the step of removing echo crosstalk that results from cross-talk on the same twisted pair.

5. The method of claim 1, wherein said removing step further comprises the step of removing far end crosstalk that results from two far end signals on adjacent twisted pair.

6. A receiver for processing a received signal on each of a plurality of twisted pair, comprising:

a front end processor for generating a vector representation of said received signal, wherein said vector representation includes a component for each of said twisted pair; and

a cross-talk canceller for removing cross-talk from said received signal by applying said vector representation of said received signal to a multi-dimensional finite impulse response filter having matrix coefficients, wherein said cross-talk canceller reduces redundant operations performed on said received signal relative to an implementation that employs a scalar representation of said received signal.

7. The receiver of claim 6, wherein said cross-talk canceller is further configured to remove near-end crosstalk that results from a signal on one twisted pair interfering with a signal on another twisted pair.

8. The receiver of claim 6, wherein said cross-talk canceller is further configured to remove echo crosstalk that results from cross-talk on the same twisted pair.

9. The receiver of claim 6, wherein said cross-talk canceller is further configured to remove far end crosstalk that results from two far end signals on adjacent twisted pair.

10. A method for processing a received signal on each of a plurality of twisted pair, said method comprising the steps of:

generating a vector representation of said received signal, wherein said vector representation includes a component for each of said twisted pair; and

applying said vector representation of said received signal to a multi-dimensional finite impulse response filter having matrix coefficients to process said received signal, wherein said applying step reduces redundant operations performed on said received signal relative to an implementation that employs a scalar representation of said received signal.

11. The method of claim 10, further comprising the step of equalizing said received signal.

12. The method of claim 10, wherein said applying step further comprises the step of removing near-end crosstalk that results from a signal on one twisted pair interfering with a signal on another twisted pair.

13. The method of claim 10, wherein said applying step further comprises the step of removing echo crosstalk that results from cross-talk on the same twisted pair.

14. The method of claim 10, wherein said applying step removes cross-talk from said received signal.

15. The method of claim 10, wherein said applying step equalizes said received signal.