Abstract: A method of reducing crosstalk into a victim line from disturber lines in a communication system may include obtaining a pilot matrix and a measurement vector associated with the pilot matrix, the pilot matrix representing pilot signals transmitted by at least the disturber lines, the measurement vector being influenced by the pilot signals via the crosstalk; estimating estimated crosstalk coefficients of significant ones of the disturber lines by solving a reduced linear system using only non-clipped measurements in the measurement vector, the reduced linear system being derived from the pilot matrix; determining compensation coefficients to reduce the crosstalk based on the estimated crosstalk coefficients; and reducing crosstalk by one or more of pre-compensating signals transmitted on the victim line and post-compensating signals received on the victim line based on the compensation coefficients.

Abstract: At least one example embodiment discloses a method including determining a first set of lines and a second set of lines in a system, obtaining signals to be transmitted over, or received from, the first set of lines and the second set of lines, obtaining normal operation interval (NOI) vectoring coefficients for the second set of lines, determining discontinuous operation interval (DOI) vectoring coefficients for the first set of lines, the DOI vectoring coefficients for the first set of lines and the NOI vectoring coefficients for the second set of lines being part of a vectoring matrix and jointly processing the signals for a discontinuous operation interval using the vectoring matrix.

Abstract: A method of reducing crosstalk into a victim line from disturber lines in a communication system may include obtaining a pilot matrix and a measurement vector associated with the pilot matrix, the pilot matrix representing pilot signals transmitted by at least the disturber lines, the measurement vector being influenced by the pilot signals via the crosstalk; estimating estimated crosstalk coefficients of significant ones of the disturber lines by solving a reduced linear system using only non-clipped measurements in the measurement vector, the reduced linear system being derived from the pilot matrix; determining compensation coefficients to reduce the crosstalk based on the estimated crosstalk coefficients; and reducing crosstalk by one or more of pre-compensating signals transmitted on the victim line and post-compensating signals received on the victim line based on the compensation coefficients.

Abstract: In one example embodiment, a system including a plurality of ports, a plurality of vectoring processors, each of the plurality of vectoring processors having a coefficient memory storing vectoring coefficients corresponding to different victim line and disturber line combinations of a plurality of communication paths connected to the plurality of ports, at least one victim line associated with two of the plurality of vectoring processors and a controller, the controller being configured to assign the victim line and disturber line combinations to the memories based on loads associated with the vectoring coefficients.

Abstract: In one example embodiment, a method includes determining a first set of first lines and a second set of second lines in a system, obtaining input signals to be transmitted over the first set of first lines and the second set of second lines, determining a vectoring matrix, processing, within the first set, the incoming signals for the first lines in parallel based on the vectoring matrix, processing, within the second set, the input signals for the second lines in parallel based on the vectoring matrix and processing the first set and the second set sequentially based on the vectoring matrix, the processing the second set being based on at least a portion of the processing the incoming signals for the first lines.

Abstract: In one example embodiment, a method includes obtaining a crosstalk channel and a channel matrix and determining a power controlling matrix, the power controlling matrix for regulating powers corresponding to a plurality of active communication lines. The method further includes determining a vectoring matrix based on applying the power controlling matrix to the crosstalk channel and generating vectored signals using the vectoring matrix for communication of data over the plurality of active communication lines.

Abstract: In one example embodiment, a system including a plurality of ports, a plurality of vectoring processors, each of the plurality of vectoring processors having a coefficient memory storing vectoring coefficients corresponding to different victim line and disturber line combinations of a plurality of communication paths connected to the plurality of ports, at least one victim line associated with two of the plurality of vectoring processors and a controller, the controller being configured to assign the victim line and disturber line combinations to the memories based on loads associated with the vectoring coefficients.

Abstract: A central node of a MIMO system may transmit, to one or more communication terminals of the MIMO system, a long-duration downlink pilot signal carrying a pilot sequence having a first duration. The first duration may be equal to or greater than a quantity of antennas of the central node. The central node may receive retransmitted long-duration downlink pilot signals from the communication terminals. The central node may further transmit, to one or more communication terminals, a short-duration downlink pilot signal carrying a pilot sequence having a second duration. The second duration may be less than or equal to the quantity of antennas. The central node may receive a retransmitted short-duration downlink pilot signal from the one or more communication terminals. An uplink and downlink between the central node and one or more communication terminals may be estimated based on the received signals.

Abstract: At least one example embodiment discloses a method of determining crosstalk for at least one first line in a communication system having a plurality of second lines. The method includes obtaining at least one pilot matrix representing a sequence of pilot signals and transmitting pilot signals across the plurality of second lines in accordance with the at least one pilot matrix. The method further includes obtaining measurement vectors for the at least one first line on a plurality of subcarriers, in response to the transmitted pilot signals, determining a weighted vector, the weighted vector being a weighted combination of the measurement vectors and determining a crosstalk coupling vector based on the determined weighted vector.

Abstract: A central node of a MIMO system may transmit, to one or more communication terminals of the MIMO system, a long-duration downlink pilot signal carrying a pilot sequence having a first duration. The first duration may be equal to or greater than a quantity of antennas of the central node. The central node may receive retransmitted long-duration downlink pilot signals from the communication terminals. The central node may further transmit, to one or more communication terminals, a short-duration downlink pilot signal carrying a pilot sequence having a second duration. The second duration may be less than or equal to the quantity of antennas. The central node may receive a retransmitted short-duration downlink pilot signal from the one or more communication terminals. An uplink and downlink between the central node and one or more communication terminals may be estimated based on the received signals.

Abstract: In one example embodiment, a method includes determining a first set of first lines and a second set of second lines in a system, obtaining input signals to be transmitted over the first set of first lines and the second set of second lines, determining a vectoring matrix, processing, within the first set, the incoming signals for the first lines in parallel based on the vectoring matrix, processing, within the second set, the input signals for the second lines in parallel based on the vectoring matrix and processing the first set and the second set sequentially based on the vectoring matrix, the processing the second set being based on at least a portion of the processing the incoming signals for the first lines.

Abstract: In accordance with an embodiment, the method includes inserting a plurality of crosstalk probing signals within the wired multi-carrier communication system for probing the crosstalk from respective ones of the plurality of disturber lines into the victim line, carrying out crosstalk measurements over the victim line, and estimating the crosstalk coefficients from the crosstalk measurements. The method further includes organizing the plurality of disturber lines into subsets of disturber lines, and individually assigning disjoint groups of carriers to the respective subsets of disturber lines. The insertion of the plurality of crosstalk probing signals is confined within the respectively assigned groups of carriers. The subsets of disturber lines and/or the groups of carriers used for a second or subsequent iteration are tailored based on crosstalk characteristics observed for the respective disturber lines during a pervious iteration.

Abstract: At least one example embodiment discloses a method of determining crosstalk for at least one first line in a communication system having a plurality of second lines. The method includes obtaining at least one pilot matrix representing a sequence of pilot signals and transmitting pilot signals across the plurality of second lines in accordance with the at least one pilot matrix. The method further includes obtaining measurement vectors for the at least one first line on a plurality of subcarriers, in response to the transmitted pilot signals, determining a weighted vector, the weighted vector being a weighted combination of the measurement vectors and determining a crosstalk coupling vector based on the determined weighted vector.

Abstract: At least one example embodiment discloses a method of reducing crosstalk in a system. The method includes obtaining a plurality of groups of lines based on crosstalk characteristics of the system, lines in a same group of lines being permitted to be active during a same time slot, identifying a first set of lines associated with data to send and a second set of lines associated with no data to send, the first set of lines being designated for transmission during a selected time slot, modifying the first set of lines in accordance with the plurality of groups of lines and transmitting symbols during the selected time slot using the modified first set of lines.

Abstract: In one example embodiment, a method includes obtaining a crosstalk channel and a channel matrix and determining a power controlling matrix, the power controlling matrix for regulating powers corresponding to a plurality of active communication lines. The method further includes determining a vectoring matrix based on applying the power controlling matrix to the crosstalk channel and generating vectored signals using the vectoring matrix for communication of data over the plurality of active communication lines.

Abstract: At least one example embodiment discloses a method including determining a first set of lines and a second set of lines in a system, obtaining signals to be transmitted over, or received from, the first set of lines and the second set of lines, obtaining normal operation interval (NOI) vectoring coefficients for the second set of lines, determining discontinuous operation interval (DOI) vectoring coefficients for the first set of lines, the DOI vectoring coefficients for the first set of lines and the NOI vectoring coefficients for the second set of lines being part of a vectoring matrix and jointly processing the signals for a discontinuous operation interval using the vectoring matrix.

Abstract: At least one example embodiment discloses a method of reducing crosstalk in a system. The method includes obtaining a plurality of groups of lines based on crosstalk characteristics of the system, lines in a same group of lines being permitted to be active during a same time slot, identifying a first set of lines associated with data to send and a second set of lines associated with no data to send, the first set of lines being designated for transmission during a selected time slot, modifying the first set of lines in accordance with the plurality of groups of lines and transmitting symbols during the selected time slot using the modified first set of lines.

Abstract: At least one example embodiment discloses a method of determining crosstalk for a joining line in a communication system having a plurality of current active lines. The method includes obtaining a number of disturber lines among the plurality of current active lines, the number of disturber lines being less than a number of the plurality of current active lines, obtaining a pilot matrix, a first dimension of the pilot matrix being based on the number of disturber lines, the pilot matrix representing a sequence of pilots to be transmitted across the plurality of current active lines and the joining line, the first dimension being a number of time instances, the number of time instances being less than the number of the plurality of active lines and determining a crosstalk coupling vector for the joining line based on the pilot matrix.

Abstract: At least one example embodiment discloses a method of determining crosstalk for a joining line in a communication system having a plurality of current active lines. The method includes obtaining a number of disturber lines among the plurality of current active lines, the number of disturber lines being less than a number of the plurality of current active lines, obtaining a pilot matrix, a first dimension of the pilot matrix being based on the number of disturber lines, the pilot matrix representing a sequence of pilots to be transmitted across the plurality of current active lines and the joining line, the first dimension being a number of time instances, the number of time instances being less than the number of the plurality of active lines and determining a crosstalk coupling vector for the joining line based on the pilot matrix.

Abstract: In one embodiment, the method includes determining, at an access node, a precoder matrix for precoding transmission from the access node to a plurality of downstream devices over a plurality of lines. The plurality of lines include high power lines and low power lines. The high power lines are in active communication and transmit more symbols per frame than the low power lines. The method further includes precoding a signal vector using the precoder matrix regardless of the symbols the signal vector is sending over the low power lines. Here, the determining determines the precoder matrix such that the precoding does not mitigate the cross-talk effect the high power lines have on the low power lines. The method also includes transmitting over the plurality of lines based on the precoded signal vector.