System and method for high-speed decoding and ISI compensation in a multi-pair transceiver system

• US 7,711,077 B2
• Filed: 11/12/2008
• Issued: 05/04/2010
• Est. Priority Date: 11/13/1998
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Kruse, David, Hatamian, Mehdi, Agazzi, Oscar E., Abnous, Arthur
• Primary Examiner(s): Tran; Khanh C
• Application Number:
  US12/269,697
• Publication Number:
  US 20090067559A1
• Time in Patent Office: 538 Days
• Field of Search: 375232-233, 375/346, 375/348, 375/350, 370/286, 370290-291
• US Class Current: 375/348
• CPC Class Codes: G01R 31/3004 Current or voltage test
• CPC Class Codes: G01R 31/3008 Quiescent current [IDDQ] test or leakage current test
• CPC Class Codes: G01R 31/3016 Delay or race condition test, e.g. race hazard test
• CPC Class Codes: G01R 31/31715 Testing of input or output circuits; test of circuitry between the I/C pins and the functional core, e.g. testing of input or output driver, receiver, buffer
• CPC Class Codes: G01R 31/318502 Test of Combinational circuits
• CPC Class Codes: G01R 31/318552 Clock circuits details
• CPC Class Codes: G01R 31/318594 Timing aspects clock circuits G01R31/318552
• CPC Class Codes: H03M 13/256 with trellis coding, e.g. with convolutional codes and TCM
• CPC Class Codes: H03M 13/41 using the Viterbi algorithm or Viterbi processors
• CPC Class Codes: H04B 3/23 using a replica of transmitted signal in the time domain, e.g. echo cancellers
• CPC Class Codes: H04B 3/32 Reducing cross-talk, e.g. by compensating
• CPC Class Codes: H04L 1/0054 Maximum-likelihood or sequential decoding, e.g. Viterbi, Fano, ZJ algorithms
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/242 by comparing a transmitted test signal with a locally generated replica
• CPC Class Codes: H04L 2025/03363 Multilevel H04L2025/03369 takes precedence
• CPC Class Codes: H04L 2025/03369 Partial response
• CPC Class Codes: H04L 2025/03458 Lattice
• CPC Class Codes: H04L 2025/03477 not time-recursive
• CPC Class Codes: H04L 2025/0349 as a feedback filter
• CPC Class Codes: H04L 2025/03496 as a prediction filter
• CPC Class Codes: H04L 2025/03503 : as a combination of feedback and prediction filters
• CPC Class Codes: H04L 2025/03617 : Time recursive algorithms H04L2025/03643 takes precedence
• CPC Class Codes: H04L 2025/03643 : Order recursive
• CPC Class Codes: H04L 2025/03745 : Timing of adaptation
• CPC Class Codes: H04L 25/03038 : with a non-recursive structure H04L25/03031 takes precedence
• CPC Class Codes: H04L 25/03057 : with a recursive structure H04L25/03031 takes precedence
• CPC Class Codes: H04L 25/03146 : with a recursive structure H04L25/03127 takes precedence
• CPC Class Codes: H04L 25/03203 : Trellis search techniques
• CPC Class Codes: H04L 25/03267 : with decision feedback equalisers
• CPC Class Codes: H04L 25/03324 : Provision of tentative decisions
• CPC Class Codes: H04L 25/067 : providing soft decisions, i.e. decisions together with an estimate of reliability H04L25/068 and H04L25/069 take precedence; sequence estimation techniques H04L25/03178
• 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
• CPC Class Codes: H04L 25/4917 : using multilevel codes
• CPC Class Codes: H04L 25/497 : by correlative coding, e.g. partial response coding or echo modulation coding transmitters and receivers for partial response systems transversal equalizers at the transmitter end H04L25/03343
• CPC Class Codes: H04L 7/0062 : detection of error based on data decision error, e.g. Mueller type detection
• CPC Class Codes: H04L 7/0334 : Processing of samples having at least three levels, e.g. soft decisions

Abstract

A method and a system for providing ISI compensation to an input signal in a bifurcated manner. ISI compensation is provided in two stages, a first stage compensates ISI components induced by characteristics of a transmitter'"'"'s partial response pulse shaping filter, a second stage compensates ISI components induced by characteristics of a multi-pair transmission channel. First stage ISI compensation is performed in an inverse response filter having a characteristic feedback gain factor K, during system start-up. Second stage ISI compensation is performed by a single DFE in combination with a MDFE operating on tentative decisions output from a Viterbi decoder. As the DFE of the second stage reaches convergence, the feedback gain factor K of the first stage is ramped to zero.

Claims

1. A receiver for demodulating an analog signal transmitted by a remote transmitter over a transmission channel, the receiver comprising:

an analog front end, including an analog-to-digital converter, the analog front end receiving and converting the analog signal to a digital signal;

an adaptive receive filter for reducing a first interference component in the first digital signal and outputting a second digital signal, wherein the impulse response of the adaptive receive filter is initialized according to the impulse response of a transmit filter in the remote transmitter;

an interference canceller for reducing a second interference component in the second digital signal and outputting a third digital signal, wherein the second interference component comprises a signal intended for another receiver; and

a decoder for decoding the third digital signal.

2. The receiver of claim 1, wherein the first interference component is an intersymbol interference component.

3. The receiver of claim 1, wherein the adaptive receive filter is represented by a transfer function of the form 1/(Kz⁻

1), wherein K is a characteristic feedback gain factor and z is a z-transform.

4. The receiver of claim 1, wherein the adaptive receive filter comprises at least one feedback tap.

5. The receiver of claim 4, wherein the gain of at least one feedback tap converges to zero.

6. The receiver of claim 1, wherein the second interference component comprises a signal generated by a transmitter associated with the receiver.

7. The receiver of claim 1, wherein the interference canceller estimates the second interference component.

8. The receiver of claim 1, wherein the interference canceller comprises an adaptive filter for modeling the second interference component.

9. The receiver of claim 1, wherein the third digital signal comprises a third interference component.

10. The receiver of claim 9, wherein the third interference component comprises interference induced by a characteristic of the transmission channel.

11. A method for demodulating an analog signal transmitted by a remote transmitter over a transmission channel, the method comprising:

(a) receiving the analog signal in an analog front end;

(b) converting the analog signal to a first digital signal;

(c) compensating for a first interference component included in the first digital signal using an adaptive filter to produce a second digital signal, wherein the impulse response of the adaptive filter is initialized according to the impulse response of a transmit filter in the remote transmitter;

(d) compensating for a second interference component included in the second digital signal to produce a third digital signal, wherein the second interference component comprises a signal intended for another receiver; and

(e) decoding the third digital signal.

12. The method of claim 11, wherein the first interference component is an intersymbol interference component.

13. The method of claim 11, wherein the adaptive receive filter is represented by a transfer function of the form 1/(Kz⁻

1), wherein K is a characteristic feedback gain factor and z is a z-transform.

14. The method of claim 11, wherein the adaptive receive filter comprises at least one feedback tap.

15. The method of claim 14, wherein the gain of at least one feedback tap converges to zero.

16. The method of claim 11, wherein the second interference component comprises a signal generated by a transmitter associated with the receiver.

17. The method of claim 11, wherein the method comprises estimating the second interference component.

18. The method of claim 11, wherein the method comprises modeling the second interference component.

19. The method of claim 11, wherein the third digital signal comprises a third interference component.

20. The method of claim 19, wherein the third interference component comprises interference induced by a characteristic of the transmission channel.