At&t Intellectual Property I, L.p.

Adaptive Spectrum and Signal Alignment, Incorporated

Thomas Starr

Thomas Arnold Anschutz

Peter Joshua Silverman

George Ginis

A method for reinforcing signals on coupled channels during idle periods transmits a first signal on a destination channel and a second signal on a source channel. The second signal is formulated to produce an optimal signal coupled into the destination channel to reinforce the first signal and is sent during idle periods in the source channel.

Systems and methods for reinforcing signals on coupled channels during idle periods

A method includes identifying, at a processor of a crosstalk analyzer, a first communication line of a plurality of communication lines and a second communication line of the plurality of communication lines. The first communication line and the second communication line identified based on a correlation of a crosstalk parameter with respect to the first communication line and the second communication line. The method also includes, responsive to identifying the first communication line and the second communication line, assigning, by the processor, the first communication line to a first port of an access node and the second communication line to a second port of the access node.

System and method to reduce crosstalk of digital subscriber lines

A system that incorporates teachings of the present disclosure may include, for example, a controller to: determine crosstalk coupling characteristics between a plurality of lines of a digital subscriber line system connected to a plurality of modems based on a transition between a full power mode and one or more other modes, and provide the determined crosstalk coupling characteristics to one or more of the plurality of modems for performance of at least one of pre-coding a transmitted signal and processing a received signal along a line of the plurality of lines, where the pre-coding and processing is performed based at least in part on the determined crosstalk coupling characteristics, and where the pre-coding of the transmitted signal and the processing of the received signal reduce effects of fluctuating crosstalk. Other embodiments are disclosed.

Method and apparatus for reducing noise in a communication system

A method includes identifying, at a processor, a set of communication lines from a plurality of communication lines, the set of communication lines including a first communication line and a second communication line. A first crosstalk characteristic of the first communication line is correlated with a second crosstalk characteristic of the second communication line. The method also includes modifying, at the processor, a first signal corresponding to the first communication line based on a second signal corresponding to the second communication line.

A computer implemented method includes determining crosstalk characteristics of a plurality of digital subscriber lines. The computer implemented method includes identifying pairs of digital subscriber lines, each of the pairs including a first digital subscriber line and a second digital subscriber line, where the first digital subscriber line has a crosstalk characteristic that is correlated to the second digital subscriber line. The computer implemented method also includes rearranging terminations at an access node to assign at least one of the identified pairs of digital subscriber lines to a common vectoring group.

A system that incorporates teachings of the present disclosure may include, for example, a controller to: determine crosstalk coupling characteristics between a plurality of lines of a Digital Subscriber Line (DSL) system connected to a plurality of modems based on a transition between a full power mode and one or more other modes, and provide the determined crosstalk coupling characteristics to one or more of the plurality of modems for performance of at least one of pre-coding a transmitted signal and processing a received signal along a line of the plurality of lines, where the pre-coding and processing is performed based at least in part on the determined crosstalk coupling characteristics, and where the pre-coding of the transmitted signal and the processing of the received signal reduce effects of fluctuating crosstalk. Other embodiments are disclosed.

A digital subscriber line (DSL) network provides enhanced dynamic spectrum management (DSM) based on estimated foreign interference obtained from monitoring unmanaged wire pairs in a cable. A DSL access multiplexer (DSLAM) or other line terminal provides vectored DSL signaling to a plurality of subscribers via a first set of wire pairs of the cable. The DSLAM monitors a second set of one or more wire pairs of the cable that are not connected to the vectored group associated with the first set of wire pairs to estimate foreign interference introduced to the first set of wire pairs. The DSLAM then modifies the vectored DSL transmitted signaling responsive to the estimated foreign interference so as to pre-cancel or otherwise compensate for the foreign interference introduced into the managed wire pairs.

Monitoring non-managed wire pairs to improve dynamic spectrum management performance

Systems and methods to mitigate impulse noise are provided. A particular method includes providing a signal from a transmission source to a mitigator. The mitigator checks the signal for complex impulse noise comprising at least a first periodic impulse noise component correlated to a first portion of a sinusoid representing frequency of an alternating current power source associated with the transmission source and a second periodic impulse noise component correlated to a second portion of the sinusoid. The method further includes receiving noise mitigation instructions from the mitigator at the transmission source to compensate for the complex impulse noise.

Impulse noise mitigation

Methods and apparatus to reduce errors during a re-transmission performed by a communication module are disclosed. An example method includes detecting an error in received data, predicting a time interval that is expected to be substantially error-free, and transmitting a re-transmission request message for the data based on the time interval.

Methods and apparatus to reduce errors during a re-transmission

In a signal transmission medium such as an ac power line, impulse noise in the line may be dealt with by detecting impulse noise in the transmission medium, determining whether the impulse noise is periodic or complex, and, at least approximately, correlating the time at which periodic impulse noise occurs in the transmission medium to the phase of the ac power line frequency. One or more noise mitigation techniques may be applied with respect to the impulse noise. Methods also include predicting at least the approximate time of the next periodic noise impulse, and at least its approximate occurrence in the phase of the ac power line frequency. Methods also address impulse noise in complex impulse conditions.

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Barrington, IL, United States of America

Thomas Starr