摘要:
The measurement of far-end crosstalk (FEXT) in a Digital Subscriber Line communications is instrumental in the ability of using a multiple input multiple output (MIMO) pre-coder to cancel FEXT. A reliable robust back channel for transmission of error is instrumental to provide error samples for the proper operation of a MIMO pre-coder. Bins can be dedicated to insure bandwidth from the customer premises equipment (CPE) to the central office (CO). By increasing the margin used in the bins, robustness can be added to this back channel between the CPE and CO.
摘要:
The measurement of far-end crosstalk (FEXT) in a Digital Subscriber Line communications is instrumental in the ability of using a multiple input multiple output (MIMO) pre-coder to cancel FEXT. A reliable robust back channel for transmission of error is instrumental to provide error samples for the proper operation of a MIMO pre-coder. Bins can be dedicated to insure bandwidth from the customer premises equipment (CPE) to the central office (CO). By increasing the margin used in the bins, robustness can be added to this back channel between the CPE and CO.
摘要:
Systems and methods are described for selecting tones for far-end crosstalk (FEXT) mitigation. In particular, systems and methods are described for performing far-end crosstalk (FEXT) mitigation within a digital subscriber line (xDSL) system. One embodiment is a method that comprises determining a first set of function values relating to a per-tone signal-to-noise ratio (SNR) for a user among a plurality of users for a number of tones, wherein the number of tones is less than or equal to a total number of tones available for transmission. The method further comprises estimating coefficients for performing FEXT mitigation for the number of tones, performing FEXT mitigation on the number of tones based on the estimated coefficients, and performing FEXT mitigation on a selected group of tones from among the number of tones, wherein the selected group of tones is less than or equal to the number tones.
摘要:
Systems and methods are described for selecting tones for far-end crosstalk (FEXT) mitigation. In particular, systems and methods are described for performing far-end crosstalk (FEXT) mitigation within a digital subscriber line (xDSL) system. One embodiment is a method that comprises determining a first set of function values relating to a per-tone signal-to-noise ratio (SNR) for a user among a plurality of users for a number of tones, wherein the number of tones is less than or equal to a total number of tones available for transmission. The method further comprises estimating coefficients for performing FEXT mitigation for the number of tones, performing FEXT mitigation on the number of tones based on the estimated coefficients, and performing FEXT mitigation on a selected group of tones from among the number of tones, wherein the selected group of tones is less than or equal to the number tones.
摘要:
In accordance with one embodiment, a method is implemented in a vectored system for improving a signal-to-noise ratio (SNR) of a far end transmitted signal on a victim line in the system. The method comprises mitigating, by the vectored system, self-induced far-end crosstalk (self-FEXT) on the victim line based on self-FEXT mitigation coefficients and receiving, by a second sensor, information relating to at least one of: self-FEXT of the vectored system, external noise, and the far end transmitted signal. The method further comprises learning, at the second sensor, coefficients relating to self-FEXT coupling into the second sensor and removing self-FEXT from the second sensor based on the learned coefficients. Upon removal of self-FEXT from the second sensor, a linear combiner configured to combine information relating to the victim line and the second line is learned. The method further comprises applying the learned linear combiner and readjusting the self-FEXT mitigation coefficients to remove any residual self-FEXT on the victim line after application of the learned linear combiner.
摘要:
In accordance with one embodiment, a method is implemented in a vectored system for improving a signal-to-noise ratio (SNR) of a far end transmitted signal on a victim line in the system. The method comprises mitigating, by the vectored system, self-induced far-end crosstalk (self-FEXT) on the victim line based on self-FEXT mitigation coefficients and receiving, by a second sensor, information relating to at least one of: self-FEXT of the vectored system, external noise, and the far end transmitted signal. The method further comprises learning, at the second sensor, coefficients relating to self-FEXT coupling into the second sensor and removing self-FEXT from the second sensor based on the learned coefficients. Upon removal of self-FEXT from the second sensor, a linear combiner configured to combine information relating to the victim line and the second line is learned. The method further comprises applying the learned linear combiner and readjusting the self-FEXT mitigation coefficients to remove any residual self-FEXT on the victim line after application of the learned linear combiner.
摘要:
Systems and methods for partial self-FEXT (far-end crosstalk) are described. One method, among others, comprises determining one or more instantaneous characteristics of an input signal, wherein the one or more instantaneous characteristics comprise one or more of amplitude of the input signal and an energy level of the input signal. The method further comprises selecting one or more disturbers to cancel according to the one or more instantaneous characteristics, wherein selecting one or more disturbers is performed on a per-DMT (discrete multi-tone) symbol basis.
摘要:
Systems and methods for partial self-FEXT (far-end crosstalk) are described. One method, among others, comprises determining one or more instantaneous characteristics of an input signal, wherein the one or more instantaneous characteristics comprise one or more of amplitude of the input signal and an energy level of the input signal. The method further comprises selecting one or more disturbers to cancel according to the one or more instantaneous characteristics, wherein selecting one or more disturbers is performed on a per-DMT (discrete multi-tone) symbol basis.
摘要:
Included are embodiments for retransmission in a digital subscriber line environment. At least one embodiment of a method includes framing data into transport frames, each transport frame carrying payload data that is viewed differently according to the computing layer in which it is transported; transporting the transport frames over a first computing layer, the payload data of each transport frame corresponding to an integer number Q of elementary cells of the first computing layer, an integer number of header bytes containing information specific to the transport frame, and an integer number of padding bytes; and transporting the transport frames over a second computing layer, the payload data content of each transport frame corresponding to payload data of an integer number M of elementary cells of the second computing layer.
摘要:
A method implemented in a digital subscriber line (DSL) system is described for minimizing a misdetection probability at a far-end coded message receiver during transmission of a coded message. The method comprises jointly determining, at the far-end coded message receiver, a P matrix and a modulation scheme. The method further comprises encoding a message into a coded message with a systematic linear block code, the systematic linear block code having a generator matrix [I P], where I represents a linear block code component identity matrix and P represents the determined P matrix. The method also comprises modulating the encoded message to one or more tones forming a discrete multi-tone (DMT) symbol according to the determined modulation scheme.