# US 12,627,331 B2 · Gain adaptation for downstream vectoring systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,627,331 B2 - Document ID: US12627331B2 - Status: Granted - Kind: B2 - Application number: 17/571,928 - Filed: 2022-01-10 - Published: 2022-07-14 - Granted: 2026-05-12 - Earliest claimed: 2013-01-11 - Assignees: Alcatel Lucent - Applicants: Alcatel Lucent - Inventors: Jochen Maes; Michael Timmers; Dirk Vanderhaegen; Carl Nuzman; Danny Van Bruyssel - Web page: https://patentgrep.com/patent/US12627331B2 ## CPC - H04B 3/32: Reducing cross-talk, e.g. by compensating - H04B: TRANSMISSION ## Abstract In accordance with an embodiment, the method includes detecting an update event whereupon a precoder needs to be updated, sending signal adjustment information to a receiver remotely coupled to a subscriber line out of the plurality of subscriber lines indicative of a signal compensation factor to be applied to a receive communication signal to compensate for a channel bias caused by the scheduled precoder update, and time-coordinating the precoder update with the enforcement of the signal compensation factor at the receiver. ## Claims ### Claim 1 A communication controller for controlling a communication over a subscriber line out of a plurality of subscriber lines, the communications over the plurality of subscriber lines making use of communication signals that are jointly processed through a linear precoder for crosstalk pre-compensation, wherein the communication controller is configured to receive signal adjustment information from a transmitter remotely coupled to the subscriber line indicative of a signal compensation factor to be applied to a receive communication signal to compensate for a channel equalization bias caused at least by a corresponding transmit signal scaling to be applied at the transmitter to scale down a transmit communication signal for conformance to a transmit Power Spectral Density (PSD) mask after joint processing of the communication signals through an updated linear precoder, the updated linear precoder being the linear precoder after a linear precoder update, and the communication controller is configured to send adjusted bit loading values in response to receiving the signal adjustment information, time-coordinate an enforcement of the signal compensation factor with the corresponding transmit signal scaling and the linear precoder update from a data symbol index received from the transmitter, and compensate for the channel equalization bias resulting from the linear precoder update based on the enforcement of the signal compensation factor with the corresponding transmit signal scaling and the linear precoder update. ### Claim 2 (depends on 1) A subscriber device comprising: the communication controller according to claim 1. ### Claim 3 A method for controlling communications over a plurality of subscriber lines, the communications making use of communication signals that are jointly processed through a linear precoder for crosstalk pre-compensation, the method comprising: updating one or more coupling coefficients of the linear precoder for mitigating crosstalk from a subscriber line into one or more victim lines, sending signal adjustment information to a receiver remotely coupled to the subscriber line indicative of a signal compensation factor to be applied to a receive communication signal to compensate for a channel equalization bias caused by crosstalk pre-compensation signals superimposed over the one or more victim lines and corresponding to the respective one or more updated coupling coefficients of the linear precoder after joint processing of the communication signals through an updated precoder, the updated precoder being the linear precoder after a precoder update; and time-coordinating the precoder update with an enforcement of the signal compensation factor at the receiver, and the sending the signal adjustment information to the receiver being in response to a determination that the precoder update results in the channel equalization bias at the receiver. ### Claim 4 (depends on 3) The method according to claim 3, wherein the signal compensation factor is a real factor that compensates for an amplitude equalization bias. ### Claim 5 (depends on 3) The method according to claim 3, wherein the signal compensation factor is a complex factor that compensates for both an amplitude equalization bias and a phase equalization bias. ### Claim 6 (depends on 3) The method according to claim 3, wherein the linear precoder is updated in two steps, a first precoder update with partial precoding gains and limited channel equalization bias, and a second precoder update with full precoding gains, and wherein the sending step takes place between the first and second precoder updates, and the second precoder update is time-coordinated with the enforcement of the signal compensation factor at the receiver. ### Claim 7 (depends on 3) The method according to claim 3, wherein the method further comprises: a step of, upon receipt of gain adjustment information, returning an adapted bit loading value and/or an adapted fine gain tuning factor for a respective carrier to a corresponding transmitter. ### Claim 8 (depends on 3) The method according to claim 3, wherein the communication signals are multi-carrier signals, and wherein gain adjustment information and the corresponding signal compensation factor are determined on a per carrier basis. ### Claim 9 A communication controller for controlling communications over a plurality of subscriber lines, the communications making use of communication signals that are jointly processed through a linear precoder for crosstalk pre-compensation, the communication controller comprising: at least one processor; and at least at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the communication controller to update one or more coupling coefficients of the linear precoder for mitigating crosstalk from a subscriber line into one or more victim lines, to send signal adjustment information to a receiver remotely coupled to the subscriber line indicative of a signal compensation factor to be applied to a receive communication signal to compensate for a channel equalization bias caused by crosstalk pre-compensation signals superimposed over the one or more victim lines and corresponding to the respective one or more updated coupling coefficients of the linear precoder, after joint processing of the communication signals through an updated precoder, the updated precoder being the linear precoder after a precoder update, and to time-coordinate the precoder update with an enforcement of the signal compensation factor at the receiver, and the sending the signal adjustment information to the receiver being in response to a determination that the precoder update results in the channel equalization bias at the receiver. ### Claim 10 (depends on 9) An access node comprising the communication controller according to claim 9. ### Claim 11 A communication controller for controlling a communication over a subscriber line out of a plurality of subscriber lines, the communications over the plurality of subscriber lines making use of communication signals that are jointly processed through a linear precoder for crosstalk pre-compensation, the communication controller comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the communication controller to receive signal adjustment information from a transmitter remotely coupled to the subscriber line indicative of a signal compensation factor to be applied to a receive communication signal to compensate for a channel equalization bias caused by crosstalk pre-compensation signals superimposed over one or more victim lines and corresponding to respective one or more updated coupling coefficients of the linear precoder after joint processing of the communication signals through an updated precoder, the updated precoder being the linear precoder after a precoder update, send adjusted bit loading values in response to receiving the signal adjustment information, time-coordinate an enforcement of the signal compensation factor with a corresponding transmit signal scaling and the linear precoder update from a data symbol index received from the transmitter, and compensate for the channel equalization bias resulting from the linear precoder update based on enforcing the signal compensation factor with the corresponding transmit signal scaling and the linear precoder update. ### Claim 12 (depends on 11) A subscriber device comprising: the communication controller according to claim 11. ### Claim 13 A communication controller for controlling a communication over a subscriber line out of a plurality of subscriber lines, the communications over the plurality of subscriber lines making use of communication signals that are jointly processed through a linear precoder for crosstalk pre-compensation, wherein the communication controller is configured to receive signal adjustment information from a transmitter remotely coupled to the subscriber line indicative of a signal compensation factor to be applied to a receive communication signal to compensate for a channel equalization bias caused at least by a corresponding transmit signal scaling to be applied at the transmitter to scale down a transmit communication signal for conformance to a transmit Power Spectral Density (PSD) mask after joint processing of the communication signals through an updated linear precoder, the updated linear precoder being the linear precoder after a linear precoder update, and the communication controller is configured to time-coordinate an enforcement of the signal compensation factor with the corresponding transmit signal scaling and the linear precoder update, and compensate for the channel equalization bias resulting from the linear precoder updated based on the enforcement of the signal compensation factor with the corresponding transmit signal scaling and the linear precoder update, wherein the communication controller is configured to time-coordinate the enforcement of the signal compensation factor with the corresponding transmit signal scaling and the linear precoder update by sending an acknowledgment signal to the transmitter. ### Claim 14 (depends on 13) The communication controller of claim 13, wherein the communication controller is configured to time-coordinate the enforcement of the signal compensation factor with the corresponding transmit signal scaling and the linear precoder update from a data symbol index onwards after sending the acknowledgment signal, or the communication controller is configured to time-coordinate the enforcement of the signal compensation factor with the corresponding transmit signal scaling and the linear precoder update from a data symbol index received from the transmitter. ### Claim 15 (depends on 3) The method of claim 3, wherein the time-coordinating of the precoder update with the enforcement of the signal compensation factor at the receiver is based on a received acknowledgment signal. ### Claim 16 (depends on 15) The method of claim 15, wherein the time-coordinating of the precoder update with the enforcement of the signal compensation factor at the receiver is from a data symbol index onwards after the received acknowledgment signal, or the time-coordinating of the precoder update with the enforcement of the signal compensation factor at the receiver is from a data symbol index sent to the receiver. ### Claim 17 (depends on 9) The communication controller of claim 9, wherein the communication controller is configured to time-coordinate the precoder update with the enforcement of the signal compensation factor at the receiver based on an acknowledgment signal. ### Claim 18 (depends on 17) The communication controller of claim 17, wherein the communication controller is configured to time-coordinate the precoder update with the enforcement of the signal compensation factor at the receiver from a data symbol index onwards after receiving the acknowledgment signal, or the communication controller is configured to time-coordinate the precoder update with the enforcement of the signal compensation factor at the receiver from a data symbol index sent to the receiver. ### Claim 19 (depends on 11) The communication controller of claim 11, wherein the communication controller is configured to enforce the signal compensation factor from the data symbol index onwards after sending an acknowledgement signal.