# US 2010/0260245 A1 · System and method for low-power echo and next cancellers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0260245 A1 - Document ID: US20100260245A1 - Status: Published application - Kind: A1 - Application number: 11/487,041 - Filed: 2006-07-13 - Published: 2010-10-14 - Earliest claimed: 2005-08-01 - Assignees: Leanics Corporation - Inventors: Keshab K. Parhi; Yongru Gu - Web page: https://patentgrep.com/patent/US20100260245A1 ## CPC - H04L 25/03038: {with a non-recursive structure (H04L25/03031 takes precedence)} - H04L 25/03343: {Arrangements at the transmitter end} - H04L 2025/03445: {Time domain} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method to design low complexity and low power echo and NEXT cancellers based on wordlength reduction technique is presented. A circuit architecture to implement echo and cancellers is also presented. The low complexity and low power design relies on the fact that a TH precoder can be viewed as an IIR filter with an input equal to the sum of the original input to the TH precoder and a compensation signal. The proposed design also relies on the fact that sum of the original input to the TH precoder and the compensation signal has finite levels, which can be represented in less bits than the original input of the echo and NEXT cancellers. An improved design by exploiting the statistics of the compensation signal is also proposed to further bring down the complexity and power consumption of these cancellers. ## Claims ### Claim 1 A communications transceiver comprising: i). N transmitters, wherein each transmitter contains a precoder, ii). N receivers, with each receiver comprising: A plurality of FIR digital filters used for Echo and Near End Crosstalk (NEXT) cancellation, with each FIR digital filter comprising: (a) Computing the sum of the input to the precoder of a transmitter and the compensation signal generated by the said precoder; (b) A first encoder coupled to the said sum; (c) A first FIR digital filter coupled to the output of the said first encoder; and (d) A first decoder coupled to the output of the said first FIR filter. ### Claim 2 (depends on 1) The communications transceiver of claim 1 wherein the encoder comprises a subtractor and a scaler. ### Claim 3 (depends on 1) The communications transceiver of claim 1 wherein the decoder contains a scaler. ### Claim 4 (depends on 1) The communications transceiver of claim 1 wherein the transceiver is used for Ethernet over copper. ### Claim 5 (depends on 1) The communications transceiver of claim 1 wherein the transceiver is operated at a symbol rate of at least 800 MBaud. ### Claim 6 (depends on 1) The communications transceiver of claim 1 wherein N=4. ### Claim 7 An integrated circuit having a substrate and a communications transceiver disposed on said substrate, said transceiver comprising: i). N transmitters, wherein each transmitter contains a precoder, ii). N receivers, with each receiver comprising: A plurality of FIR digital filters used for Echo and Near End Crosstalk (NEXT) cancellation, with each FIR digital filter comprising: (a) Computing the sum of the input to the precoder of a transmitter and the compensation signal generated by the said precoder; (b) A first encoder coupled to the said sum; (c) A first FIR digital filter coupled to the output of the said first encoder; and (d) A first decoder coupled to the output of the said first FIR filter. ### Claim 8 (depends on 7) The integrated circuit of claim 7 wherein the encoder comprises a subtractor and a scaler. ### Claim 9 (depends on 7) The integrated circuit of claim 7 wherein the decoder contains a scaler. ### Claim 10 (depends on 7) The integrated circuit of claim 7 wherein the transceiver is used for Ethernet over copper. ### Claim 11 (depends on 7) The integrated circuit of claim 7 wherein the transceiver is operated at a symbol rate of at least 800 MBaud. ### Claim 12 (depends on 7) The integrated circuit of claim 7 wherein N=4. ### Claim 13 A communications transceiver comprising: i). N transmitters, wherein each transmitter contains a precoder, ii). N receivers, with each receiver comprising: A plurality of FIR digital filters used for Echo and Near End Crosstalk (NEXT) cancellation, with each FIR digital filter comprising: (a) A first encoder coupled to the input to the precoder of a transmitter; (b) A first FIR filter coupled to the output of the said first encoder; (c) A second encoder coupled to the compensation signal generated by the precoder of the said transmitter; (d) A second FIR filter, with filter coefficients same as the said first FIR digital filter, coupled to the output of the said first encoder; and (e) Computing a sum of the output of the said first FIR filter and the output of the said second FIR filter. ### Claim 14 (depends on 13) The communications transceiver in claim 13 with multipliers in the digital filters comprising at least one multiplexer controlled by a signal generated by the said second encoder of the claim 13. ### Claim 15 (depends on 13) The communications transceiver of claim 13 wherein the transceiver is used for Ethernet over copper. ### Claim 16 (depends on 13) The communications transceiver of claim 13 wherein the transceiver is operated at a symbol rate of at least 800 MBaud. ### Claim 17 (depends on 13) The communications transceiver of claim 13 wherein N=4. ### Claim 18 An integrated circuit having a substrate and a communications transceiver disposed on said substrate, said transceiver comprising: i). N transmitters, wherein each transmitter contains a precoder, ii). N receivers, with each receiver comprising: A plurality of feed-forward digital filters used for Echo and Near End Crosstalk (NEXT) cancellation, with each FIR digital filter comprising: . (a) A first encoder coupled to coupled to the input to the precoder of a transmitter; (b) A first FIR filter coupled to the output of the said first encoder; (c) A second encoder coupled to the compensation signal generated by the precoder of the said transmitter; (d) A second FIR filter, with filter coefficients same as the said first FIR digital filter, coupled to the output of the said first encoder; and (e) Computing a sum of the output of the said first FIR filter and the output of the said second FIR filter. ### Claim 19 (depends on 18) The integrated circuit in claim 18 with multipliers in the digital filters comprising at least one multiplexer controlled by a signal generated by the said second encoder of claim 18. ### Claim 20 (depends on 18) The integrated circuit of claim 18 wherein the transceiver is used for Ethernet over copper. ### Claim 21 (depends on 18) The integrated circuit of claim 18 wherein the transceiver is operated at a symbol rate of at least 800 MBaud. ### Claim 22 (depends on 18) The integrated circuit of claim 18 wherein N=4.