Channel Quality Indicator for Wireline Channel Degradation Detection

• US 20180152326A1
• Filed: 01/23/2018
• Published: 05/31/2018
• Est. Priority Date: 12/16/2015
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Dai, Shaoan, Gu, Zhenzhong, Cheong, Kok-Wui
• Granted Patent: US 10,177,943 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04B 3/23 using a replica of transmitted signal in the time domain, e.g. echo cancellers
• CPC Class Codes: H04B 3/235 combined with adaptive equaliser
• CPC Class Codes: H04B 3/237 using two adaptive filters, e.g. for near end and for end echo cancelling
• CPC Class Codes: H04B 3/493 Testing echo effects or singing
• CPC Class Codes: H04L 2025/03802 Signalling on the reverse channel
• 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 25/03885 adaptive

Abstract

Systems and techniques relating to channel degradation detection for communication systems are described. A described system includes a processor and an interface to transmit signals and receive signals via a channel that includes a cable. The processor can be configured to perform echo cancellation based on echo tap values to remove portions of the transmitted signals that appear as echoes within the received signals, signal equalization based on equalizer tap values, or both. The processor can be configured to determine a channel quality indicator of the channel based on one or more of the echo tap values, one or more of the equalizer tap values, or both. The processor can be configured to generate a warning indication based on the channel quality indicator indicating a degradation of the cable or the channel.

Claims

1. An apparatus comprising:

an interface to transmit signals and receive signals via a channel that includes a cable; and

a processor coupled with the interface, wherein the processor is configured to perform i) echo cancellation based on echo tap values to remove portions of the transmitted signals that appear as echoes within the received signals, ii) signal equalization based on equalizer tap values, the equalizer tap values being determined based on at least a portion of the received signals to adjust an impulse response of the channel and reduce inter-symbol interference within the received signals, or iii) both the echo cancellation and the signal equalization,

wherein the processor is configured to determine a channel quality indicator of the channel based on one or more of the echo tap values, one or more of the equalizer tap values, or both one or more of the echo tap values and one or more of the equalizer tap values, and

wherein the processor is configured to generate a warning indication based on the channel quality indicator indicating a degradation of the cable or the channel.

2. The apparatus of claim 1, wherein the channel quality indicator comprises a return loss channel quality indicator of the channel that is based on one or more of the echo tap values, an insertion loss channel quality indicator of the channel that is based on one or more of the equalizer tap values, or both the return loss channel quality indicator and the insertion loss channel quality indicator.

3. The apparatus of claim 2, wherein the processor is configured to generate the warning indication based on the return loss channel quality indicator exceeding a first threshold, the insertion loss channel quality indicator exceeding a second threshold, or both.

4. The apparatus of claim 2, wherein the processor is configured to determine the return loss channel quality indicator based on a summation of absolute value versions or squared versions of the echo tap values.

5. The apparatus of claim 2, wherein the processor is configured to determine the insertion loss channel quality indicator based on a summation of absolute value versions or squared versions of the equalizer tap values.

6. The apparatus of claim 2, wherein the return loss channel quality indicator is mapped to a k-bit value, and wherein the insertion loss channel quality indicator is mapped to a k-bit value.

7. The apparatus of claim 1, wherein the channel quality indicator comprises an insertion loss channel quality indicator of the channel that is based on one or more of the equalizer tap values, wherein the processor is configured to perform the signal equalization, wherein the signal equalization comprises feedforward equalization and decision-feedback equalization, and wherein the processor is configured to adjust channel compensation from the feedforward equalization before a determination of the insertion loss channel quality indicator.

8. The apparatus of claim 7, wherein the insertion loss channel quality indicator is based on a main tap value associated with the decision-feedback equalization and a channel gain value.

9. A method comprising:

transmitting signals via a channel that includes a cable;

receiving signals via the channel;

performing i) echo cancellation based on echo tap values to remove portions of the transmitted signals that appear as echoes within the received signals, ii) signal equalization based on equalizer tap values, the equalizer tap values being determined based on at least a portion of the received signals to adjust an impulse response of the channel and reduce inter-symbol interference within the received signals, or iii) both the echo cancellation and the signal equalization;

determining a channel quality indicator of the channel based on one or more of the echo tap values, one or more of the equalizer tap values, or both one or more of the echo tap values and one or more of the equalizer tap values; and

generating a warning indication based on the channel quality indicator indicating a degradation of the cable or the channel.

10. The method of claim 9, wherein determining the channel quality indicator comprises determining a return loss channel quality indicator of the channel based on one or more of the echo tap values, determining an insertion loss channel quality indicator of the channel based on one or more of the equalizer tap values, or both.

11. The method of claim 10, wherein generating the warning indication comprises generating the warning indication based on the return loss channel quality indicator exceeding a first threshold, the insertion loss channel quality indicator exceeding a second threshold, or both.

12. The method of claim 10, wherein determining the return loss channel quality indicator comprises determining the return loss channel quality indicator based on a summation of absolute value versions or squared versions of the echo tap values.

13. The method of claim 10, wherein determining the insertion loss channel quality indicator comprises determining the insertion loss channel quality indicator based on a summation of absolute value versions or squared versions of the equalizer tap values.

14. The method of claim 9, wherein determining the channel quality indicator comprises determining an insertion loss channel quality indicator of the channel based on one or more of the equalizer tap values, wherein the signal equalization comprises feedforward equalization and decision-feedback equalization, and wherein the method comprises adjusting channel compensation from the feedforward equalization before a determination of the insertion loss channel quality indicator.

15. The method of claim 14, wherein the insertion loss channel quality indicator is based on a main tap value associated with the decision-feedback equalization and a channel gain value.

16. A system comprising:

a first device of a car, the first device comprising an interface to transmit signals and receive signals via a channel that includes a cable that is subjected to an automotive environment of the car, and a processor coupled with the interface; and

a second device of the car, the second device being communicatively coupled with the first device via the cable,

wherein the processor is configured to perform i) echo cancellation based on echo tap values to remove portions of the transmitted signals that appear as echoes within the received signals, ii) signal equalization based on equalizer tap values, the equalizer tap values being determined based on at least a portion of the received signals to adjust an impulse response of the channel and reduce inter-symbol interference within the received signals, or iii) both the echo cancellation and the signal equalization,

wherein the processor is configured to determine a channel quality indicator of the channel based on one or more of the echo tap values, one or more of the equalizer tap values, or both one or more of the echo tap values and one or more of the equalizer tap values, and

wherein the processor is configured to detect a degradation of the cable or the channel over time resulting from being subjected to the automotive environment of the car based on the channel quality indicator.

17. The system of claim 16, wherein the channel quality indicator comprises a return loss channel quality indicator of the channel that is based on one or more of the echo tap values, an insertion loss channel quality indicator of the channel that is based on one or more of the equalizer tap values, or both the return loss channel quality indicator and the insertion loss channel quality indicator.

18. The system of claim 17, wherein the processor is configured to determine the return loss channel quality indicator based on a summation of absolute or squared versions of the echo tap values, and wherein the processor is configured to determine the insertion loss channel quality indicator based on a summation of absolute or squared versions of the equalizer tap values.

19. The system of claim 17, wherein the processor is configured to generate a warning indication based on the return loss channel quality indicator exceeding a first threshold, the insertion loss channel quality indicator exceeding a second threshold, or both.

20. The system of claim 19, comprising:

on-board diagnostic system of the car,

wherein the first device is configured to forward the return loss channel quality indicator to the on-board diagnostic system, forward the insertion loss channel quality indicator to the on-board diagnostic system, or both.