Adaptive Spectrum and Signal Alignment, Incorporated

Iker Almandoz

John Matthew Cioffi

Wonjong Rhee

Georgios Ginis

Bin Hong Lee

C Thomas Sylke

Chiang-yu Chen

Bin Lee

Methods, techniques and apparatus identify members and characteristics of binders and/or other groups of communication lines such as those in a DSL system. Information obtained includes the identification (for example, by scanning) of significant crosstalking 'offenders' and their 'victims' that are affected by the crosstalk. One or a small number of modems are instructed to transmit with preselected transmit spectra, after which evidence of crosstalk in the noise spectrum data is examined for potential victim lines. Direct evidence of noise spectrum contribution by a suspected offender line may be obtained by collecting reported noise spectrum data and/or estimated noise spectrum data from potential victim lines. Also, where such direct evidence is not available, or in addition to it, other operational data showing crosstalk interference relating to potential victim lines can be used. The transmitting modem can either be on the CO/RT side or on the CPE side. Modems other than suspected offenders might transmit zero or minimal power in one or more selected frequency bands during scanning to reduce the risk that a modem and/or line not being examined for &#x201c;offender&#x201d; status supplies unnecessarily complicating and/or dominant crosstalk during the procedure. For DMT modulated DSL transceivers, well designed transmit spectra can be easily enforced by manipulating line profiles where such well designed line profiles cause minimal or no interruption to existing DSL customers. The invention also can be used to identify (partially or fully) the absolute values of crosstalk channels making up a channel transfer function.

Binder identification

A self-learning and/or self-adjusting communication controller and/or optimizer uses operational data collected from a communication system to adjust operation of the communication system to changing operational, environmental, etc. conditions and, in some embodiments, to customize operation of the communication system's lines and components so that their performance can be controlled, improved and/or optimized. In various embodiments, operational parameters and/or rules are established and/or adjusted based on information obtained from the system concerning the system's operation; information regarding margins used by a DSL system and code violation counts reported by the DSL system are used to set margin levels for one or more line sets (each line set including an individual line, a group of lines, a binder, etc.) and/or other users and/or components of the DSL system; and, the controller and/or optimizer forces a small number of test lines into as yet un-experienced and/or unimplemented operational conditions so that new knowledge can be obtained.

Self-learning and self-adjusting DSL system

Loading and ordering techniques are provided for one-sided and two-sided vectored line groups, as well as loading methodologies that also can be used on a single line, in communication systems such as Digital Subscriber Line (DSL) binders. In particular, a method for loading bits into a plurality of lines in a vectored DSL system using Discrete MultiTone (DMT) modulation is disclosed. The method iteratively determines two or more of the following sequentially: line ordering for each tone; power spectral density for the transmitted signal of each line; and bit allocation for the signal of each line. In some embodiments, line ordering may include order-swapping which may assign a first line to a first initial position, assign a second line to a second initial position, move the first line to the second initial position, and move the second line to the first initial position.

DSL system loading and ordering

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.

Tonal rotors

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.

DSL system estimation and control

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.

Digital subscriber line (DSL) state and line profile control

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. Information such as a modem type selection then can be used by the controller to generate modem and/or system operation signals to assist in operation of the DSL system.

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Palo Alto, CA, United States of America

Iker Almandoz