# US 9,882,747 B2 · Channel quality indicator for wireline channel degradation detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,882,747 B2 - Document ID: US9882747B2 - Status: Granted - Kind: B2 - Application number: 15/380,965 - Filed: 2016-12-15 - Published: 2017-06-22 - Granted: 2018-01-30 - Earliest claimed: 2015-12-16 - Assignees: Marvell World Trade Ltd. - Applicants: Marvell World Trade Ltd. - Inventors: Shaoan Dai; Zhenzhong Gu; Kok-Wui Cheong - Web page: https://patentgrep.com/patent/US9882747B2 ## CPC - H04L 25/03057: {with a recursive structure (H04L25/03031 takes precedence)} - H04B 3/23: using a replica of transmitted signal in the time domain, e.g. echo cancellers - H04B 3/235: {combined with adaptive equaliser} - H04B 3/237: {using two adaptive filters, e.g. for near end and for end echo cancelling} - H04B 3/493: Testing echo effects or singing - H04L 25/03146: {with a recursive structure (H04L25/03127 takes precedence)} - H04L 25/03885: {adaptive} - H04L 2025/03802: {Signalling on the reverse channel} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION ## Abstract Systems and techniques relating to channel degradation detection for communication systems are described. A described system includes an interface to transmit signals and receive signals via a channel that includes a cable; an echo canceller coupled with the interface, the echo canceller to perform echo cancellation based on echo tap values to remove portions of the transmitted signals that appear as echoes within the received signals; an equalizer coupled with the interface, the equalizer to perform 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; and circuitry configured to determine a return loss channel quality indicator of the channel based on the echo tap values, determine an insertion loss channel quality indicator of the channel based on the equalizer tap values, or both. ## Claims ### Claim 1 An apparatus comprising: an interface to transmit signals and receive signals via a channel that includes a cable; an echo canceller coupled with the interface, the echo canceller to perform echo cancellation based on echo tap values to remove portions of the transmitted signals that appear as echoes within the received signals; an equalizer coupled with the interface, the equalizer to perform 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; and circuitry configured to determine a return loss channel quality indicator of the channel based on the echo tap values, determine an insertion loss channel quality indicator of the channel based on the equalizer tap values, or both, and wherein the circuitry is configured to generate a warning indication based on the return loss channel quality indicator or the insertion loss channel quality indicator exceeding a threshold, the warning indication indicating a degradation of the cable or the channel. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the circuitry is configured to determine the return loss channel quality indicator based on a summation of squared versions of the echo tap values. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the circuitry is configured to determine the return loss channel quality indicator based on a summation of absolute value versions of the echo tap values. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the circuitry is configured to determine the insertion loss channel quality indicator based on a summation of squared versions of the equalizer tap values. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the circuitry is configured to determine the insertion loss channel quality indicator based on a summation of absolute value versions of the equalizer tap values. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the equalizer comprises a feedforward equalizer (FFE) and a decision-feedback equalizer (DFE), wherein the circuitry is configured to adjust channel compensation from the FFE before a determination of the insertion loss channel quality indicator, and wherein the insertion loss channel quality indicator is based on a main tap value associated with the DFE and a channel gain value. ### Claim 7 (depends on 1) The apparatus of claim 1, 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. ### Claim 8 A method, comprising: transmitting signals via a channel that includes a cable; receiving signals via the channel; performing echo cancellation based on echo tap values to remove portions of the transmitted signals that appear as echoes within the received signals; determining equalizer tap values 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; performing signal equalization based on the equalizer tap values; determining a channel quality indicator of the channel, wherein determining the channel quality indicator comprises determining a return loss channel quality indicator of the channel based on the echo tap values, determining an insertion loss channel quality indicator of the channel based on the equalizer tap values, or both; and providing the channel quality indicator to an on-board diagnostic system to detect a degradation of the cable or the channel over time. ### Claim 9 (depends on 8) The method of claim 8, comprising: generating a warning indication based on the return loss channel quality indicator or the insertion loss channel quality indicator exceeding a threshold, the warning indication indicating a degradation of the cable or the channel. ### Claim 10 (depends on 8) The method of claim 8, comprising: determining the return loss channel quality indicator based on a summation of squared versions of the echo tap values. ### Claim 11 (depends on 8) The method of claim 8, comprising: determining the return loss channel quality indicator based on a summation of absolute value versions of the echo tap values. ### Claim 12 (depends on 8) The method of claim 8, comprising: determining the insertion loss channel quality indicator based on a summation of squared versions of the equalizer tap values. ### Claim 13 (depends on 8) The method of claim 8, comprising: determining the insertion loss channel quality indicator based on a summation of absolute value versions of the equalizer tap values. ### Claim 14 (depends on 8) The method of claim 8, wherein performing the signal equalization comprises using a feedforward equalizer (FFE) and a decision-feedback equalizer (DFE), wherein the method further comprises adjusting channel compensation from the FFE before a determination of the insertion loss channel quality indicator, and wherein the insertion loss channel quality indicator is based on a main tap value associated with the DFE and a channel gain value. ### Claim 15 (depends on 8) The method of claim 8, 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. ### Claim 16 A system comprising: an on-board diagnostic system of a car; a first device of the car; and a second device of the car, wherein the second device is communicatively coupled with the first device via a channel that includes a cable that is subjected to an automotive environment of the car, wherein the first device 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, wherein the first device comprises (i) an interface to transmit signals and receive signals via the channel and (ii) a processor 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, determine equalizer tap values 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, perform signal equalization based on the equalizer tap values, and determine a return loss channel quality indicator of the channel based on the echo tap values, determine an insertion loss channel quality indicator of the channel based on the equalizer tap values, or both, and 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. ### Claim 17 (depends on 16) The system of claim 16, comprising: circuitry to generate a warning indication based on the return loss channel quality indicator or the insertion loss channel quality indicator exceeding a threshold, the warning indication indicating a degradation of the cable or the channel. ### Claim 18 (depends on 16) The system of claim 16, wherein the processor is configured to determine the return loss channel quality indicator based on a summation of squared versions of the echo tap values or a summation of absolute value versions of the echo tap values. ### Claim 19 (depends on 16) The system of claim 16, wherein the processor is configured to determine the insertion loss channel quality indicator based on a summation of squared versions of the equalizer tap values or a summation of absolute value versions of the equalizer tap values.