Abstract: Adaptive generalized decision feedback equalization (GDFE) allows variations in one or more channels and noise of a multi-line/multi-channel communication system to be tracked. Such tracking can be used in vector upstream (one-sided) situations in communication systems such as ADSL and VDSL, among others. The GDFE may be separated into adaptive and static portions and/or components. Either a feedforward section or a feedback section (or both) can be separated to create a static component and an adaptive component. The adaptive components adjust to the instantaneous channel and noise changes (for example, using the instantaneous errors and simple LMS algorithms). When the channel and noise do not exhibit any time-variation, the adaptive filters can zero themselves.

Abstract: Estimates of a communication system configuration, such as a DSL system, are based on operational data collected from a network element management system, protocol, users and/or the like. The operational data collected from the system can include performance-characterizing operational data that typically is available in an ADSL system via element-management-system protocols. Scanning, wherein a number of line profiles are used in connection with DSL loops having known configurations, can be used to generate a database or library of loop configuration information. One or more of the line profiles can be used with an unknown DSL loop to generate operational data from the unknown DSL loop that is compared to the loop configuration information in the database, allowing identification of loop configuration information pertaining to the unknown DSL loop.

Abstract: Adaptive FEC coding is used to adjust the codeword composition of FEC codewords in a communication system. A codeword composition ratio may be adjusted in response to variance of a measured transmission error value from a target transmission error value in the system. The codeword composition ratio may be any quantity or value that represents the relation between the payload and parity bytes in the applicable FEC coding scheme. Adjustment of the codeword composition ratio may be adjusting parameters such as the N, K and/or R values in ADSL1 systems or the INP and/or maximum interleaving delay values in ADSL2 systems. A controller may be used to monitor, analyze and adjust the various values used in adaptively managing FEC coding. The present invention may be implemented in a transmission system in which a transmitter transmits data to a receiver via a transmission channel, such as a DSL system.

Abstract: Superimposing phantom-mode signals reinforces existing differentially driven DSL downstream signals in a vectored binder of DSLs or reinforces upstream vectored signals in a binder of differentially excited twisted pairs, thus expanding the extra transmission modes of the previous GDSL multi-wire two-sided-excitation invention to the case where coordination can only occur on one-side of the binder. Each pair is treated as a common-mode antenna with respect to earth ground, with some pairs selectively excited at the transformer center tap at the transmit end with respect to a common (earth or chassis) ground reference. Corresponding receivers on other non-excited pairs sense the signals between their center taps and a ground at the opposite ends of the lines to the exciting transmitters. A dual use with hybrid circuits allows the receiving circuit to also have an upstream transmitter and an upstream-sensing receiver on the center tap of the opposite side of an adjacent wire.

Abstract: A set of complex rotations are used to implement a unitary “Q” matrix in which each complex rotation is a set of real rotations, where the minimum number of real rotations to perform the complex rotation is three, and where the minimum number of angles to characterize the real rotations is two. The index-angle sets for each successive rotation can be provided by a complex rotor calculation unit, which may be collocated with the complex rotor computational unit, located in a controller such as a DSL optimizer, or located in any other suitable device or apparatus that has performed the QR factorization upon supplied matrix MIMO transfer functions for the vectored channel.

Abstract: Estimates of a communication system configuration, such as a DSL system, are based on operational data collected from a network element management system, protocol, users and/or the like. The operational data collected from the system can include performance-characterizing operational data that typically is available in an ADSL system via element-management-system protocols. Generated estimates and/or approximations can be used in evaluating system performance and directly or indirectly dictating/requiring changes or recommending improvements in operation by transmitters and/or other parts of the communication system. Data and/or other information may be collected using “internal” means or may be obtained from system elements and components via email and/or other “external” means.

Abstract: Methods, apparatus, systems and computer program products address one-sided vectoring systems that include a bonded-line set having two or more bonded DSL lines within a vectored group wherein other techniques such as precoding, tonal predictive GDFEs, tonal rotors and ordering techniques can be implemented. The performance of lines within a bonded set for a single customer can be improved for both upstream and downstream by nesting a vector coding system within, for example, GDFE and/or precoder architectures. The DSL lines within such a bonded group can have rotors applied at both transmit and receive side to achieve higher performance for these lines. The triangular matrix used by the GDFE and the precoder systems of the above-referenced applications can be modified in this context.

Abstract: A high speed multiple user multiple-loop DSL system is described. In one embodiment, it includes a first DSL loop to carry DSL traffic to a first user and a second DSL loop to carry DSL traffic to a second user. A first junction connects the traffic of the first DSL loop to a third DSL loop, and a second junction connects the traffic of the second DSL loop to the third DSL loop.

Abstract: Methods, apparatus, computer program products and other embodiments model a system's channel and noise characteristics using one or more Hidden Markov Models (HMMs) by modeling the state dynamics for one or more lines and associated profiles and by learning from the line history. Besides channel and noise characteristics, user data activity also can be modeled using an HMM, where all channel, noise and user data activity can be modeled jointly using HMMs as long as the joint states are properly defined. In multi-line systems, multiple lines (for example, a set of lines in a DSL system binder) may be modeled jointly. After learning channel, noise, user data activity and/or other dynamics using HMM techniques and methods, system operation and/or configuration parameters can be controlled based on the estimated HMM, providing flexible solutions for virtually any channel, noise, user data activity and/or other dynamics.

Abstract: Minimum-memory-implementation is available with any depth and period in DSL interleaving/deinterleaving, always allowing the minimum amount of memory to be used in both transmitter and receiver without loss of performance or of basic triangular structure, even if the interleaver/deinterleaver parameters change dynamically. A novel cell-scheduling process ensures availability of the minimum amount of memory (or any other desired memory usage) to implement an image of the perfect triangle and works for any co-prime depth and interleaver period. Minimal memory use may be further characterized by a simple off-line method that determines an addressing order for each of the memory cells in a minimum-memory (or other) implementation of an interleaver/deinterleaver according to the invention. Time variation of interleaver depth in operation can be accommodated easily with absolute minimum memory requirement at all time instants.

Abstract: A DSL system includes a multiple loop segment where K loops are bonded to provide a multiple loop segment having up to (2K?1) communication channels on which transmissions are vectored. The segment may be a drop to a customer premises, an inter-pedestal link, or any other suitable part of a larger DSL system. Generally the bonded loops are relatively short, being 300 meters or less. Signal vectoring is used to increase the speed and data carrying capability of the channels. In some embodiments, an expanded frequency spectrum also can be used to increase the data carrying capability of one or more of the channels. An impedance matching circuit may be coupled to each end of the segment to provided efficient transmission of data across the segment. A controller may provide control signals used to operate the segment as a vectored system and, if desired, frequency bandwidth control signals. The controller may monitor and/or collect data and information from the DSL system to assist in generating control signals.

Abstract: Improved DSL and/or other communication system services can be provided by motivating users, service providers and operators to implement and comply with one or more operational conditions, such as parameter value limits and/or ranges, that enhance operation of the communication system. Enhanced operation can include providing a reward such as an operational benefit to one or more users and/or mitigating problems experienced by other users in the communication system, which can be one or more communication lines. A DSL line implementing and complying with one or more operational conditions is provided with a reward (such as an operational benefit like a higher maximum data rate), which is otherwise withheld if the line fails to comply with the condition(s). Each operational condition may be set and monitored by a controller, such as a DSL optimizer that collects and analyzes operational data to determine compliance.

Abstract: Operational data is utilized to determine the FEXT interference induced by one line into the other DSL line. FEXT interference can be calculated using the NEXT interference measured between the two lines at the upstream ends of the loops and the downstream channel transfer function of one of the loops. Because the NEXT and transfer function constitute a linear time-invariant system, as does the FEXT interference between the lines, the NEXT interference and line transfer function can be multiplied (if in linear format) or added (if in logarithmic format) to approximate the FEXT interference between the lines. The collection of data, calculations and other functions performed in these techniques may be performed by a system controller, such as a DSL optimizer.

Abstract: An apparatus comprises at least one vectoring engine and a cross-connect coupled to the vectoring engine. The cross-connect is to couple with each of a plurality of customer premises equipment (CPE) devices via a respective DSL loop. An interface is to receive instructions for the cross-connect to couple the vectoring engine to a nonoverlapping subset of the CPE devices via the respective DSL loops. The interface is further to receive instructions for the vectoring engine to apply vectoring to the DSL loop via which to couple one of the CPE devices to the cross-connect.

Abstract: A DSL or other communication system includes a modem or other communication device having at least one antenna that is configured to collect interference data relating to interference noise affecting communication signals being received by the communication device. The interference may include RF interference, such as AM radio interference, crosstalk and other types of interference from various sources. The interference data collected by the antenna is used by an interference canceller to remove and/or cancel some or all of the interference affecting received signals. In some embodiments of the present invention, more than one antenna may be used, wherein each antenna can collect interference data pertaining to a single source of interference noise. Where a modem or other communication device is coupled to multiple telephone lines, only one of which is being used as the active DSL line, wires in the remaining telephone lines or loops can be used as antennas.

Abstract: Controlling margins in a DSL modem pair is based on collected operational data. The operational data is analyzed and at least one of the modems in the modem pair is instructed to use a margin-related parameter value to assist the modem pair in meeting a margin target, such as a margin limit imposed by a DSL standard or the like. A controller, such as a DSM Center, a “smart” modem unit and/or a computer system can collect and analyze the operational data and generate one or more margin-related parameter values. The margin-related parameter value may be a PSD-related value, such as the MAXNOMPSD, MAXNOMATP or PSDMASK parameter used by various ADSL systems, and may be a shaped spectral mask and/or caps or limits on bit loading for use in transmissions between the modems. In some cases, preference bands can be imposed to direct modems to favor and/or avoid certain frequencies in the modem's usable band(s).

Abstract: Information is sent by a DSL system component using a non-disruptive operational data parameter. One or more bits of the non-disruptive operational data parameter are used to send other information. In some instances the selected parameter will be an unused parameter, such as an unused fast operational mode or interleaved operational mode parameter used to report operational data in a DSL system. In one embodiment of the invention, a remote modem provides a unique equipment identifier that can be paired with the telephone number on which the modem is operating. Verification of and/or searching for the correct pairing of telephone number and unique equipment identifier can be performed as well.

Abstract: Disclosed are systems and methods for evaluating whether to transition operation of a DSL line from a current line profile to one or more target line profiles. For example, in one embodiment, a method provides providing a profile transition matrix, a plurality of threshold tables, a plurality of sub-rules, and an overall rule. The method operates in the current profile and collects operational data on the DSL line. The method further performs one or more tests to evaluate the feasibility of the current line profile and each of the target line profiles, and then transitions the state to operate the DSL line in the highest feasible profile available. Evaluation of the feasibility of staying in the current state or moving to one of the target states may be based on distributions of reported and estimated data distilled from the operational data collected on the DSL line.

Abstract: Adaptive FEC coding is used to adjust the codeword composition of FEC codewords in a communication system. A codeword composition ratio may be adjusted in response to variance of a measured transmission error value from a target transmission error value in the system. The codeword composition ratio may be any quantity or value that represents the relation between the payload and parity bytes in the applicable FEC coding scheme. Adjustment of the codeword composition ratio may be adjusting parameters such as the N, K and/or R values in ADSL1 systems or the INP and/or maximum interleaving delay values in ADSL2 systems. A controller may be used to monitor, analyze and adjust the various values used in adaptively managing FEC coding. The present invention may be implemented in a transmission system in which a transmitter transmits data to a receiver via a transmission channel, such as a DSL system.

Abstract: Operational data collected from a communication system, such as a DSL system, may include exclusionary data and/or indicative data that can be analyzed to determine the type of communication device, such as a DSL modem, that generated the operational data. Exclusionary data, if any, can be used to exclude one or more communication device types from consideration. Indicative data, if any, may be used to influence the selection of a communication device type, such as by assigning scores to communication device type features and/or to communication device types. Information pertaining to various communication devices may be maintained in a database or the like. In a DSL system, modem types may be evaluated and selected by a modem identification unit or identifier that collects and analyzes the operational data using collecting means and identifying means. The identifier may be part of a controller, such as a DSM Center or the like implemented in and/or with a computer and coupled to the DSL system.