Equalization for multichannel receiving node

• US 6,621,862 B1
• Filed: 01/04/2000
• Issued: 09/16/2003
• Est. Priority Date: 01/04/2000
• Status: Expired due to Term

• Current Assignee: Alcatel Internetworking Incorporated (Nokia Corporation)
• Original Assignee: Alcatel Internetworking Incorporated (Nokia Corporation)
• Inventors: Dabell, Steve
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): WILLIAMS, DEMETRIA A
• Application Number:
  US09/477,509
• Time in Patent Office: 1,351 Days
• Field of Search: 375/229, 375/232, 375/233, 375/316
• US Class Current: 375/229
• CPC Class Codes: H04L 2025/03363 Multilevel H04L2025/03369 takes precedence
• CPC Class Codes: H04L 2025/03477 not time-recursive
• CPC Class Codes: H04L 25/03038 with a non-recursive structure H04L25/03031 takes precedence
• CPC Class Codes: H04L 25/14 Channel dividing arrangements , i.e. in which a single bit stream is divided between several baseband channels and reassembled at the receiver

Abstract

An equalization method and apparatus for equalizing a plurality of input signals received on a multichannel link leverages shared equalization resources to generate dedicated tap coefficients for application to the signals and updates the dedicated tap coefficients upon measured degradation in the quality of the signals. The equalization method and apparatus achieves acceptable bit error rates with relatively low overhead.

Claims

1. An equalization apparatus, comprising:

a plurality of inputs for receiving respective input signals;

an equalization controller coupled to the inputs for receiving the respective input signals and generating respective tap coefficients therefrom;

a plurality of signal filters coupled to respective inputs and the equalization controller, for receiving the respective input signals and the respective tap coefficients and generating respective output signals therefrom; and

a plurality of performance monitors coupled to respective signal filters and the equalization controller, for receiving the respective output signals and applying feedback to the equalization controller upon determining that the bit error rates for the respective output signals exceeds a predetermined threshold,

wherein said feedback comprises a priority level determined in relation to a magnitude by which the respective output signals has exceeded the predetermined threshold.

2. The apparatus according to claim 1, wherein the equalization controller is further operative for updating the respective tap coefficients upon receiving said feedback from respective performance monitors.

3. The apparatus according to claim 1, wherein a plurality of tap coefficients are generated from each input signal.

4. The apparatus according to claim 3, wherein each signal filter includes means for applying an input signal as a first input to a plurality of multiply functions, each multiply function having as a second input a different one of the tap coefficients generated therefrom to generate a plurality of products, and applying the plurality of products to an accumulate function to generate an output signal.

11. The apparatus according to claim 1, wherein the equalization controller updates the tap coefficients based on the priority level of the respective feedback.

5. An equalization method for improving the quality of signals received over a multichannel link using a shared tap coefficient function, comprising the steps of:

receiving a plurality of input signals;

sampling the input signals individually;

applying the samples individually to the tap coefficient function to generate coefficients; and

applying the coefficients to the input signals from which the coefficients were generated to generate a plurality of output signals;

transmitting the output signals;

determining the bit error rate of the output signals individually; and

repeating the sampling, applying, applying and transmitting steps for an output signal upon determining the bit error rate for the output signal exceeds a predetermined threshold.

6. Apparatus including an equalization controller shared among a plurality of input signals for generating a dedicated tap coefficient for each input signal including, for each input signal, sampling the input signal in a first instance and applying the first sample as an input to a tap coefficient algorithm, and for updating the dedicated tap coefficient for each input signal including, for each input signal, sampling the input signal in a second instance in accordance with feedback and applying the second sample as an input to the tap coefficient algorithm.

7. Apparatus according to claim 6 wherein a plurality of tap coefficients are generated for each input signal in each instance.

8. Apparatus according to claim 7 further comprising a configurable filter for receiving one of the input signals and for generating an output signal therefrom, including applying the input signal as a first input to a plurality of multiply functions, each multiply function having as a second input a different tap coefficient from within the plurality of tap coefficients generated for the input signal and received from the equalization controller to generate a plurality of products, and applying the plurality of products to an accumulate function.

9. Apparatus according to claim 6 further comprising a performance monitor for receiving an output signal generated from one of the input signals and the dedicated tap coefficient for the input signal, comparing the bit error rate of the output signal with a predetermined threshold and applying a feedback signal to the equalization controller if the output signal exceeds the predetermined threshold.

10. Apparatus according to claim 9 wherein the feedback signal includes a priority level.