In some aspects, a calibration method includes performing a write/read test for each one of multiple combinations of write/read delay settings, wherein each one of the multiple combinations of write/read delay settings includes one of a plurality of write delay settings of a first delay device and one of a plurality of read delay settings of a second delay device. The method also includes obtaining test results for the write/read tests, determining a pass region based on the test results, determining a center of the pass region, and selecting one of the multiple combinations of write/read settings based on the center of the pass region.
G06F 13/16 - Gestion de demandes d'interconnexion ou de transfert pour l'accès au bus de mémoire
G11C 7/22 - Circuits de synchronisation ou d'horloge pour la lecture-écriture [R-W]Générateurs ou gestion de signaux de commande pour la lecture-écriture [R-W]
G11C 11/4096 - Circuits de commande ou de gestion d'entrée/sortie [E/S, I/O] de données, p. ex. circuits pour la lecture ou l'écriture, circuits d'attaque d'entrée/sortie ou commutateurs de lignes de bits
G11C 29/12 - Dispositions intégrées pour les tests, p. ex. auto-test intégré [BIST]
2.
Power line communication interference probing and measurement on digital subscriber lines
This disclosure provides systems, methods, and apparatus for wireline communication. A digital subscriber line (DSL) receiver may detect one or more power line communication (PLC) sound packets and measure PLC signal leakage on a set of DSL lines based on the detected sound packets. For example, PLC sound packets may be transmitted by PLC devices within a PLC network, and impulse noise received on the set of DSL lines corresponding to the transmitted PLC sound packet may be detected by a DSL receiver (such as a consumer premises equipment (CPE)). The DSL receiver may measure PLC signal leakage on the set of DSL lines based on the detected PLC sound packets. In some cases, the PLC sound packets may be detected based on a duration, a position, or an arrival time of a PLC sound packet.
H04B 7/04 - Systèmes de diversitéSystèmes à plusieurs antennes, c.-à-d. émission ou réception utilisant plusieurs antennes utilisant plusieurs antennes indépendantes espacées
H04M 3/18 - Centraux automatiques ou semi-automatiques avec des moyens pour diminuer les interférencesCentraux automatiques ou semi-automatiques avec des moyens pour diminuer les effets dus aux défauts de ligne
H04B 3/54 - Systèmes de transmission par lignes de réseau de distribution d'énergie
H04M 11/06 - Transmission simultanée téléphonique et de données, p. ex. transmission télégraphique sur les mêmes conducteurs
Techniques are described for reducing shared cache memory requests in a multi-threaded microprocessor-based system. One method includes receiving a request for data from a thread, identifying that the request correlates with a pending request associated with a different thread, combining the request with the pending request based on the identifying, and receiving the data after the combining, the receiving being based on the pending request. In some examples, the request may be associated with an address of a cache line in a cache memory.
Methods, systems, and devices are described for wired communication. A first distribution point uses sets of modems to communicate with a second distribution point over a crosstalk link to exchange information and coordinate the use of multiple sets of frequency bands. In some cases, the first distribution point may share a cable binder with the second distribution point and detect crosstalk on the subscriber lines in the cable binder. Based at least in part on the crosstalk detected by the first distribution point, the first and second distribution points may communicate over a crosstalk link between sets of lines in the binder. The distribution points may use one or more sets of predefined tones within the multiple sets of frequency bands to exchange messages, where the messages may include synchronization information, operating parameters, or control and data information.
Methods, systems, and devices are described for wired communication. In one aspect, a distribution point may use a redundant number of digital subscriber line (DSL) lines that share a same cable binder to cancel crosstalk. For example a first distribution point may use a redundant number of lines, which may be virtualized lines, to cancel interference between lines controlled by the first distribution point and lines controlled by a second distribution point. In some cases, a distribution point may share precoding and cancelling coefficients with another distribution point over a cloud network or other service to enable vectoring without sharing transmitted data between the two distribution points. That is, the first distribution point may receive information related to crosstalk between sets of CPEs without receiving data transmitted by a separate distribution point sharing the same cable binder, and use the crosstalk related information to cancel crosstalk.
Methods, systems, and devices are described for wired communication. In one aspect, a method relates to an approach to determine a coefficient based at least in part on a weighted average of multiple estimates of a coefficient from known (e.g., stored) coefficients. The weighted average approach may improve coefficient determination. For example, a weighted average interpolation/extrapolation approach is used to determine vectoring coefficients from known vectoring coefficients in a vectored DSL system. Such an approach may provide a significant improvement in the SNR performance of the system, for example, as compared to coefficients obtained by linear interpolation. The weighted average may be of a linear interpolation, a forward extrapolation and a backward extrapolation of the particular coefficient being determined. As such, linear interpolation, forward extrapolation and backward extrapolation may be leveraged to improve accuracy of the determined coefficient.
A method and a system for preventing phantom data communication links from occurring that substantially eliminates or reduces at least some of the disadvantages and problems associated with previous data communication network management techniques. In accordance with a particular embodiment of the present disclosure a method for managing data communications is provided that comprises the step of providing a central office data communication switch that comprises a plurality of data communication ports. A port controller causes the ports to estimate various physical characteristics of the incoming signals from network termination points. This processing of incoming signals leads to the precise detection of phantom links and their immediate termination. Thus, this method prevents the formation of phantom links that may occur if physical conductors which are susceptible to crosstalk interference with connected conductors erroneously convey a response signal back to an unattached port within the head-in switching system.
Methods, systems, and devices are described for wired communication. In one aspect, a method includes selecting a gain scalar based at least in part on a constellation point distance associated with a constellation mapper for a line and a tone. The method also includes applying the gain scalar to a tone data output signal of a vector processor.
Embodiments of the invention relate to methods and apparatuses for performing hybrid rejection that overcome various shortcomings of the prior art. In one embodiment, the transformer's receive winding is stacked on top of the transmit winding, the two being wired in series and in phase. Z2 is scaled by approximately half so as to maintain the same receive gain. In another embodiment, rather than stacking the receive and transmit windings for series summation, they are each used as independent sources into the summing junction of the receive amp. If Z2 and Z3 are equal, then an equal proportion of V1 and V2 are summed.
The present invention relates generally to data communications, and more particularly to techniques based on the G.fast protocol for managing operation around potentially degrading un-cancellable crosstalk among separate vector groups implemented in a single G.fast based box located at a network distribution point, referred to as a Distribution Point Unit (DPU). In embodiments, techniques according to the invention configure transmission of signals from the different vector groups so as to avoid or prevent transmission of signals, either in the frequency domain or time domain or a combination of the two, from causing severe degradation in performance due to un-cancelled crosstalk among the separate groups,
The present invention relates generally to characterizing loops in a communication system, and more particularly to methods and apparatuses for loop gauge identification. In accordance with certain aspects, embodiments of the invention extract some information from the SELT signal. From SELT, the loop impedance, or equivalently input impedance, is determined. This information is then used for gauge identification.
According to general aspects, embodiments of the invention provide an analog front end (AFE) capable of combining two independent 106 MHz G.fast baseband transmission channels into a single 212MHz wide G.fast transmission channel, In these and other embodiments, an AFE according to the invention is also capable of interfacing to a single 212MHz G.fast transmission channels as well as a single 106MHz G.fast transmission channel.
According to certain aspects, the present invention provides techniques to address G.fast and/or digital subscriber line (DSL) transmission at frequencies below and above 106 MHz in support of aggregate service rates well above 1 Gbps on short loops based on combining two independent first generation G.fast transceivers, each operating up to 106MHz, into a single transceiver, capable of operating up to 212MHz and achieving service rates of up to 2 Gbps. In these and other embodiments, a sub-band approach is used in which a total bandwidth is divided into two or more sub-bands, with communications for one or both of the first generation G.fast transceivers using one or both of the sub-bands, respectively.
In general, the present invention provides an efficient usage of Far End Crosstalk (FEXT) coefficient memory in a G.fast vectoring system. According to certain aspects, embodiments of the invention provide a simple scheme for efficient management of the Discontinuous (DO) and Regular Operation (RO) FEXT coefficient memories to handle the complexity of lines joining/leaving the system in both regular and DO groups. In embodiments, by disabling the power-efficient, Discontinuous Operation, a G.fast system according to the invention first frees up the DO coefficient memory. Next, the system uses this memory as the staging area to manage joining/leaving events. Finally the system re-enables to the power-efficient Discontinuous Operation and re-populates the DO coefficient memory.
In general, the present invention is related to methods and apparatuses for performing an efficient update of Far-End Cross Talk (FEXT) coefficients for use with Discontinuous Operation (DO) in G.fast systems. In embodiments, to maintain separate FEXT coefficient matrices for both the Regular Operation (RO) group and the smaller DO group, the updates to the DO coefficient matrix are performed independently from the updates to the RO coefficient matrix, In these and other embodiments, the updates are performed using LMS updates and known data symbols, and with the same frequency as the LMS updates to the RO coefficient matrix.
The present invention provides a method and apparatus to detect a missing micro-data filter. In embodiments, the detection is performed by measuring the distortion caused by an unfiltered telephone device using a SELT (Single Ended Line Test) technique. According to certain aspects, the signal used to perform the distortion measurement is designed such that it causes minimal impact on vectored lines within the same cable. So the proper choice of signal parameters to ensure minimal disturbance of vectored lines depends on the loop length. Accordingly, embodiments of the invention first determines the estimated loop length, then uses the loop length to select a set of signal parameters that will be used to perform the distortion measurement. The parameters to be selected include transmit frequency band and PSD level. According to further aspects, embodiments of the invention include automatically running a missing filter test immediately following a line drop to determine if the line drop was caused by a missing micro-data filter.
The present invention relates to a method by which an xDSL modem can be properly connected and/or optimally tuned to achieve a desired performance goal based on knowledge obtained by first performing a SELT test and then post-processing the results of that test. In embodiments, the processed SELT results are used to detect bad connections or other anomalies such as split pairs. In embodiments, the processed SELT results are used to configure programmable components and filters in the analog front end in a manner that achieves the performance goal, In these and other embodiments, the performance goal is to maximize the attainable data rate. As such, through various hardware design options and configurations according to the invention, the performance of the modem can be tuned such that even in the presence of undesirable loop characteristics, adequate, or even good performance, can be achieved.
The present invention is related to improvements to SELT testing, and more particularly to methods and apparatuses for reducing the effects of distortions of the reflected signal without sacrificing the integrity of the original signal. In embodiments, a method according to the invention consists of first modifying the transmit sequence to utilize and better "excite" the low frequency tones, In embodiments, the method includes compensating for transformer roll-off at low frequencies, In other embodiments, the method includes filling gaps in the received frequency domain S I 1 sequence with a predicted, or estimated, version of the SI 1 signal.
According to certain aspects, the present invention improves upon the conventional TCAM scheme by allowing a traditional TCM scheme to be used while in RCM mode. In a RCM mode according to embodiments of the invention, the system uses traditional TCM + SNR margin (i.e. SNRM) with a receiver controlled bit allocation table (BAT) and tone ordering table (TOT). In a TCAM mode according to embodiments of the invention, the system uses uncoded hierarchical modulation similar to the modulation originally proposed for TCAM. According to certain aspects, the transmitter in RCM mode in embodiments of the invention can determine when line conditions require a switch to TCAM mode, and signal the transition to the receiver. Likewise, when in a TCAM mode according to embodiments of the invention, the receiver can request to switch back to RCM via a SRA mechanism, for example.
The present invention is directed to methods and apparatuses for performing concurrent vectoring of systems having communications performed at different symbol rates. In embodiments, where a common binder includes different sub-groups of lines having corresponding different symbol rates, the invention includes methods and apparatuses for managing and concurrently vectoring all the lines of the different sub-groups.
The present invention is directed to methods and apparatuses for performing concurrent vectoring of systems having communications performed at different symbol rates. In embodiments, where a common binder includes different sub-groups of lines having corresponding different symbol rates, the invention includes methods and apparatuses for managing and concurrently vectoring all the lines of the different sub-groups.
H04B 3/32 - Réduction de la diaphonie, p. ex. par compensation
H04L 12/911 - Contrôle d’admission au réseau et allocation de ressources, p.ex. allocation de bande passante ou renégociation en cours de communication
H04L 12/927 - Allocation de ressources en fonction du type de trafic, qualité de service ou priorité
H04M 11/06 - Transmission simultanée téléphonique et de données, p. ex. transmission télégraphique sur les mêmes conducteurs
H04B 1/38 - Émetteurs-récepteurs, c.-à-d. dispositifs dans lesquels l'émetteur et le récepteur forment un ensemble structural et dans lesquels au moins une partie est utilisée pour des fonctions d'émission et de réception
22.
METHODS AND APPARATUSES FOR CHARACTERIZING COMMON MODE NOISE AND ESTIMATING LOOP IMBALANCE
The present invention relates generally to addressing performance issues in xDSL communication systems, and more particularly to methods and apparatuses to measure and characterize CM noise impacting a DSL line in a customer premises, measurements and characterization of the projection of these CM signals in Differential Mode (DM), and finally a derivation of an estimate of the loop balance.
According to certain aspects, the present invention provides methods and apparatuses for managing a low power mode in xDSL systems, and more particularly directed to a L2 mode exit procedure for VDSL systems that is robust and quick. In embodiments, parameters for exiting a low power mode are communicated between upstream and downstream modems before the low power mode is entered, According to certain aspects, these parameters include configurations for incrementally exiting low power mode in a plurality of stages. Embodiments of the invention include quickly estimating SNR at one or more stages of this plurality of stages. Additional or alternative embodiments include reliably signaling the beginning of low power mode exit. According to certain aspects, such signaling can include a synchro sequence of inverted and normal sync symbols.
The present invention relates to methods and apparatuses for managing the time slots in time division duplex (TDD) frames in an xDSL system. According to certain aspects, power savings in a TDD system operating with vectoring may be achieved with sending of quiet symbols in time slots that do not have data and through the efficient configuration of time slots with data and/or idle symbols so as to limit the amount of processing by the vectoring engine within the DO portion of each TDD frame, In embodiments, a central controller in a DPU monitors the data buffers at the transmitter input on each line and computes an optimal configuration of the time slots in the DO portion of the TDD frame to achieve an optimal balance between performance and power dissipation.
The present invention relates to methods and apparatuses for extending the benefits of vectoring technology to xDSL systems including disparate types of xDSL lines, In embodiments, the invention includes a scheme to match the symbol frequencies of ADSL2 and VDSL2 lines, to then enable vectoring of ADSL2 FEXT into VDSL2 lines.
H04L 12/28 - Réseaux de données à commutation caractérisés par la configuration des liaisons, p. ex. réseaux locaux [LAN Local Area Networks] ou réseaux étendus [WAN Wide Area Networks]
26.
METHOD AND APPARATUS FOR INITIATING AND DATA COLLECTION OF SINGLE ENDED LINE TEST ON CUSTOMER PREMISES EQUIPMENT
According to certain aspects, embodiments of the invention relate to methods and apparatuses for performing diagnostics on a loop in a communications system. According to certain aspects, embodiments of the invention include performing SELT from a customer premises side of the loop. According to certain other aspects, embodiments of the invention address the issue of initiating a CPE side SELT procedure and also collecting the diagnostics data while a CPE is offline.
H04L 12/26 - Dispositions de surveillance; Dispositions de test
H04L 12/20 - Dispositions pour la fourniture de services particuliers aux abonnés pour convertir la vitesse de transmission de la vitesse inhérente d'une sous-station à la vitesse inhérente d'autres sous-stations
27.
METHOD AND APPARATUS FOR DESIGNING AN IMPROVED TRANSMIT SIGNAL FOR USE IN A SINGLE ENDED LINE TEST (SELT)
The present invention relates to methods and apparatuses of using a novel transmit signal that can be used to improve performance of various loop diagnostic features of SELT. In embodiments, a novel transmit signal uses a wide contiguous band of tones that includes frequencies in both upstream and downstream bands. In these and other embodiments of the invention, the SELT transmit signal is designed such that any crosstalk noise in adjacent lines appears as a burst of noise that falls within the limits of the FEC settings of the system such that it can be fully corrected without harming the performance of modems connected on the adjacent lines.
H04L 12/26 - Dispositions de surveillance; Dispositions de test
H04L 12/20 - Dispositions pour la fourniture de services particuliers aux abonnés pour convertir la vitesse de transmission de la vitesse inhérente d'une sous-station à la vitesse inhérente d'autres sous-stations
28.
METHOD AND APPARATUS FOR DETECTING AND LOCATING LOOP IMPAIRMENTS
According to certain aspects, the present invention relates to methods and apparatuses to identify and locate a line-cuts in a loop that may or may not also contain bridgetaps. In embodiments, different bands of SELT signal data are analyzed separately using a TDR method, to effectively detect any potential bridgetaps, In these and other embodiments, by combining information from the separate bands, bridgetap locations and lengths are determined. Methodology is also established to distinguish legitimate line cut or bridgetap signal data from spurious data. According to certain aspects, embodiments of the invention also incorporate baselining, which includes tests to make sure that there are no inconsistencies or imperfections that can corrupt the SELT data.
According to certain aspects, embodiments of the invention relate to methods and apparatuses to detect loss of connectivity due to improper connection near the CPE modem (i.e, small loop condition) based on the analysis of SELT. In embodiments, this condition is detected based on separately analyzing the location and levels of time domain signals associated with different transmission bands in an xDSL bandplan.
The present invention relates generally to a customer premises based method for detecting the presence of a micro-filter on a VDSL connection. According to certain aspects, the method uses SELT test signals that are transmitted from the customer premises modem and whose associated echo signals are received and analyzed by the customer premises modem, According to further aspects, specific characteristics of several different SELT signals are utilized to robustly and effectively determine the presence or absence of the micro-filter/splitter.
H04B 3/20 - Réduction des effets d'échos ou de sifflementSystèmes à ligne de transmission Détails ouverture ou fermeture de la voie d'émissionCommande de la transmission dans une direction ou l'autre
In general, the present invention relates to systems and methods to facilitate timing recovery and loop timing operations in a TDD communication system with significantly varying intervals of inactivity between periods of transmission. According to certain aspects, to facilitate timing recovery, embodiments of the invention define a maximum period of inactivity for each mode of transmission and associated "timing keep alive" signals during and/or between transmissions to assist the timing recovery function in the receiver. In embodiments, the receiver selects the desired format of the "timing keep alive" signal. According to further aspects, the timing recovery mechanisms of the invention maintain power saving objectives of G.fast, where power dissipation varies near linearly with traffic demand.
The present invention generally relates to a method and apparatus for effectively detecting and characterizing noise and other events affecting a communications system such as DSL. According to certain aspects, the invention includes a noise analysis engine that is embedded in customer premises equipment that classifies noise sources according to their specific characteristics and tracks each noise source in a dynamic manner, in such a way as to provide visibility to the changing noise environment within the customer premises and/or report this environment to a remote entity.
The present invention relates to methods and apparatuses for of communicating loss of connectivity to the end-user without the end-user explicitly asking for that information, as well as communicating potential mechanisms to restore the loss of connectivity, In embodiments, after detecting loss of connectivity within the CPE, user requests are redirected to a local web server on the fly, which is running on the CPE, The local webserver returns informational status web pages describing the situation, potential causes, and possible steps to fix the connectivity issue.
H04L 12/28 - Réseaux de données à commutation caractérisés par la configuration des liaisons, p. ex. réseaux locaux [LAN Local Area Networks] ou réseaux étendus [WAN Wide Area Networks]
H04L 12/26 - Dispositions de surveillance; Dispositions de test
G06F 17/00 - Équipement ou méthodes de traitement de données ou de calcul numérique, spécialement adaptés à des fonctions spécifiques
34.
METHOD AND APPARATUS FOR SENSING NOISE SIGNALS IN A WIRELINE COMMUNICATIONS ENVIRONMENT
The present invention relates to methods and apparatuses for sensing noise sources in a wireline communications environment such as a customer premises environment in a DSL system. In embodiments, the invention includes an additional sensor that is connected to power mains in a DSL customer premises environment either to characterize, at their source, noises coupling into the DSL l ines, and/or to mitigate their impact into the DSL lines. One objective is associated with diagnostics that help to better characterize the noise signals themselves and derive correlation of signals sensed from the power mains and their possible projection- onto the DSL line. Another objective makes use of these power line sensor signals to mitigate or to eliminate power line noises that make their way onto the DSL line. Example embodiments further include and exploit signals from additional secondary sensors such as secondary common mode, differential mode and phantom mode sensors.
The present invention generally relates to an impulse noise canceller for DSL systems. According to certain aspects, embodiments of the invention provide a dual sensor receiver to deal with the impulse noise effectively. The second sensor can be incorporated by either a common mode or unused differential port. Alternatively a power line sensor can also act as a sensor. According to certain additional aspects, embodiments of the invention provide various alternative implementations of an impulse noise canceller within a DSL receiver, According to still further aspects, embodiments of the invention provide methods for selectively training an impulse noise canceller in the various implementations,
In general, the present invention provides methods and apparatuses for exploiting the extra degree of freedom provided by the sensing of the CM signal along with the DM signal at the receiver end of a wireline communication system. According to certain aspects, this extra degree of freedom can be used to cancel alien noises at the receiver in both upstream downstream directions. According to further aspects, a CM channel can be potentially used to exploit the diversity created in the CM channel along with the regular DM channel. This acts as the motivation for employing a diversity receiver scheme at the receiver, especially in downstream communications received at a Customer Premises.
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.
Embodiments of the invention provide a robust mechanism to isolate transceivers that attempt to train on a FEXT channel during the handshake phase and to abort a false activation. According to aspects of the invention, either or both transceiver acknowledges the unique identity of the other transceiver during the handshake phase. This ensures that the transceiver progresses to training and beyond with only one other remote transceiver.
In general, the present invention relates to methods and systems for optimizing the precoder coefficient compression parameters for reducing the storage and other demands on a vectored DSL system. Embodiments of the invention can be implemented in conjunction with various existing coefficient compression techniques such as quantization of coefficients and decimation in frequencies, According to certain aspects, the compression parameters (e.g. Golomb modulus and quantization level) are selected for each of a plurality of macrobands so as to optimize the overall data rate of the system for any given channel condition, According to further aspects, the compression parameters are computed to ensure that the compressed coefficients for all macrobands do not exceed the available memory allocated for storing the coefficient data.
H04L 12/20 - Dispositions pour la fourniture de services particuliers aux abonnés pour convertir la vitesse de transmission de la vitesse inhérente d'une sous-station à la vitesse inhérente d'autres sous-stations
40.
Method and apparatus for DMT network data transfer
A multi-tone modem has a plurality of shared and discrete components forming a transmit path and a receive path configured to couple to a wired communication medium for packet based communication thereon. The transmit path includes components for forming a communication packet including a hybrid preamble portion and a data portion. The hybrid preamble portion integrates both synch and timing info for packet alignment together with header information for determining at least packet destination, thereby shortening packet length by avoiding a requirement of a distinct header portion. The receive path includes components operative in a time domain to detect, in a stream of digitized samples, a symbol alignment of a received communication packet based on synch and timing info in the hybrid preamble portion thereof and operative in a frequency domain to extract header information from the hybrid preamble.
Derivations of new PHY layer diagnostics primitives are based on the normalized error samples collected through G.993.5. The processing uses the ERB and L2 Ethernet packet encapsulation of these ERB data in order to abstract the processing from the PHY layer device dependency, as well as to allow a local and remote processing of the primitives for diagnostics purposes.
DSL backchannel data and/or information is transported upstream in a vectored, bonded line DSL system. Backchannel data (e.g., error samples or the like from downstream-end DSL equipment) is encapsulated/packetized using Layer 2 encapsulation. Upstream user data is packetized into Ethernet packets or the like. The backchannel data and upstream user data are combined and the combined data transmitted to an upstream-end DSL apparatus, such as an access node. The combined data are separated in the upstream-end DSL apparatus so that the upstream user data can be processed further. The Layer 2 encapsulated backchannel data is decapsulated and then routed to a vectoring control entity or the like for use in operating the DSL system, for example in mitigating FEXT crosstalk in the DSL system's operation.
Derivations of new PHY layer diagnostics primitives are based on the normalized error samples collected through G.993.5. The processing uses the ERB and L2 Ethernet packet encapsulation of these ERB data in order to abstract the processing from the PHY layer device dependency, as well as to allow a local and remote processing of the primitives for diagnostics purposes.
DSL backchannel data and/or information is transported upstream in a vectored, bonded line DSL system. Backchannel data (e.g., error samples or the like from downstream-end DSL equipment) is encapsulated/packetized using Layer 2 encapsulation. Upstream user data is packetized into Ethernet packets or the like. The backchannel data and upstream user data are combined and the combined data transmitted to an upstream-end DSL apparatus, such as an access node. The combined data are separated in the upstream-end DSL apparatus so that the upstream user data can be processed further. The Layer 2 encapsulated backchannel data is decapsulated and then routed to a vectoring control entity or the like for use in operating the DSL system, for example in mitigating FEXT crosstalk in the DSL system's operation.
In general, methods and apparatus according to the invention mitigate these and other issues by implementing caching techniques described herein. So when one device in a home network downloads and plays a particular content (e.g., a video, song) from a given site, the content is cached within the network such that the same content is available to be re-played on another device without re-downloading the same content from the Internet.
Methods, apparatuses (e.g., DSL system hardware, DSL systems, vectoring control entities), techniques, systems, etc. are used for initializing one or more DSL lines joining a vectored DSL line group operating in Showtime. A super-periodic orthogonal pilot sequence from a set of super-periodic orthogonal pilot sequences is assigned to each joining DSL line, wherein each such super-periodic orthogonal pilot sequence in the set has length L and is orthogonal to other sequences in the set over length T. These super-periodic orthogonal pilot sequences are used on the joining DSL lines to generate at least T sync-symbols worth of initialization data, which is processed to generate initialization data and FEXT mitigation coefficients for use when the joining DSL lines become part of the vectored DSL line group.
A DSL system performs crosstalk cancellation using a plurality of vectoring cancellation chips that are partitioned into two or more groups based on DSL victim lines or DSL disturber lines or DSL tones. Embodiments of the invention include both single-criteria and double-criteria partitioning methods. In double-criteria embodiments, the vectoring cancellation VCE chips are first partitioned into two or more victim DSL line groups and then in each group the VCE chips are further partitioned by disturber DSL line processing. Alternately, the vectoring cancellation VCE chips are first partitioned into two or more disturber DSL line groups and then within each group further partitioned by victim DSL line processing. According to certain aspects, by partitioning the computation as described herein, the invention reduces the bandwidth and the number of links between the chips, without too much co-ordination complexity. This makes it feasible to partition across a larger number of chips, thereby allowing crosstalk cancellation across larger vectored groups.
A system, method, and a computer readable medium having instructions thereupon for synchronized multi-user multi-carrier communications are provided. For example, a synchronized multi-user multi-carrier communication system includes a transmitter, a receiver communicatively coupled to the transmitter via a plurality of communication channels associated with multiple users, and a computing device, coupled to at least one of the transmitter and the receiver, comprising a memory device in communication with one or more processors. The one or more processors are configured to obtain noise samples for the plurality of communication channels, determine a coupling between carriers on the plurality of communication channels, determine a noise model for a carrier based upon the noise samples and the determined coupling, and store the noise model in the memory device.
Alien noise is removed from one or more receptor DSL lines after self-FEXT has been eliminated or reduced. Information about the alien noise in the form of slicer errors can be obtained from one or more donor DSL lines that may or may not be in the same domain (e.g., a vectored DSL system).
Residual FEXT resulting from intended and/or inherent partial cancellation of crosstalk in vectored DSL systems impairs upstream power back-off (UPBO) as traditionally implemented. By considering and taking into account the effects of residual crosstalk on vectored DSL system performance and operation, improved data rates and/or other vectored DSL system performance are realized through the use of UPBO parameters generated for a given residual FEXT environment.
The memory storage, transmission and processing demands of a vectored DSL system are reduced by sampling a subset of DSL tones in the DSL tone range used in the vectored system. This data is smoothed (denoised) to further reduce the data's size, sacrificing some fidelity or precision as a result. Finally, lossless entropy coding or the like is performed to encode the FEXT cancellation data for storage and use. The resulting data is less likely to cause transmission bottlenecks in the vectored system, can be stored and used more efficiently for both on-chip and off-chip vectoring implementations, and can be readily updated in various ways.
The memory storage, transmission and processing demands of a vectored DSL system are reduced by sampling a subset of DSL tones in the DSL tone range used in the vectored system. This data is smoothed (denoised) to further reduce the data's size, sacrificing some fidelity or precision as a result. Finally, lossless entropy coding or the like is performed to encode the FEXT cancellation data for storage and use. The resulting data is less likely to cause transmission bottlenecks in the vectored system, can be stored and used more efficiently for both on-chip and off-chip vectoring implementations, and can be readily updated in various ways.
H04J 1/12 - Dispositions pour réduire la diaphonie entre canaux
H04B 3/20 - Réduction des effets d'échos ou de sifflementSystèmes à ligne de transmission Détails ouverture ou fermeture de la voie d'émissionCommande de la transmission dans une direction ou l'autre
53.
Systems and methods for transporting time-of-day information in a communication system
Systems and methods for synchronizing a clock at a customer premises equipment (CPE) location with a master clock at a central office (CO) location are described. One embodiment is a method that comprises receiving, by a time-of-day transmission convergence (ToD-TC) module in the CPE, ToD information relating to the master clock. Based on the received information, time stamps are applied to reference data samples. The method further comprises transporting the ToD information by transporting the reference data samples with applied time stamps and utilizing time stamps of the reference data samples to synchronize the CPE clock with the master clock.
G06F 1/12 - Synchronisation des différents signaux d'horloge
G06F 15/16 - Associations de plusieurs calculateurs numériques comportant chacun au moins une unité arithmétique, une unité programme et un registre, p. ex. pour le traitement simultané de plusieurs programmes
H04L 7/06 - Commande de vitesse ou de phase au moyen de signaux de synchronisation les signaux de synchronisation différant des signaux d'information en amplitude, polarité ou fréquence
54.
SYSTEMS AND METHODS FOR TRANSPORTING TIME-OF-DAY INFORMATION IN A COMMUNICATION SYSTEM
Systems and methods for synchronizing a clock at a customer premises equipment (CPE) location with a master clock at a central office (CO) location are described. One embodiment is a method that comprises receiving, by a time-of-day transmission convergence (ToD-TC) module in the CPE, ToD information relating to the master clock. Based on the received information, time stamps are applied to reference data samples. The method further comprises transporting the ToD information by transporting the reference data samples with applied time stamps and utilizing time stamps of the reference data samples to synchronize the CPE clock with the master clock.
Disclosed are various embodiments for performing retransmission with on-line reconfiguration. A data stream is encoded into first frames according to a framing configuration. A request is obtained for an on-line reconfiguration of the framing configuration from a receiver. The encoding of the data stream into the first frames is suspended in response to the request. One or more first frames are retransmitted to the receiver during a retransmission time period that commences relative to the suspending of the encoding of the data stream into the first frames. The encoding of the data stream into second frames is resumed according to a modified framing configuration consistent with the on-line reconfiguration. The second frames are transmitted to the receiver upon expiration of the retransmission time period.
Disclosed are various embodiments for a gateway device that can execute applications which can communicate with various devices in one or more home networks as well as one or more wide area networks. The gateway device can possess capabilities to communicate over various types of proprietary and/or standardized networks. Additionally, the gateway device can be equipped with the ability to communicate with home devices that are directly coupled to the gateway device. The gateway device can also include a mass storage component that allows storage of data on behalf of applications executed therein.
H04L 12/28 - Réseaux de données à commutation caractérisés par la configuration des liaisons, p. ex. réseaux locaux [LAN Local Area Networks] ou réseaux étendus [WAN Wide Area Networks]
57.
METHOD AND SYSTEM TO CONFIGURE AND MANAGE BROADBAND-ENABLED DIGITAL COMMAND AND CONTROL SYSTEMS
Methods and systems to create and configure broadband-enabled digital command and control systems are disclosed. A disclosed method example includes presenting a system user who enables a suite of applications to be downloaded to the user's mobile device (e.g., cellular phone), command and control gateway (referred herein to as a "resident digital manager" or "RDM"), and/or network server that thereafter self authenticates for security purposes three communication junctures within the system and thereafter allows the user to configure the mobile device, resident digital manager/RDM, and/or network server for use as a digital command and control system capable of controlling a myriad of functions in the home, whether related to entertainment functions or otherwise.
One embodiment is a method for performing 2-wire line imbalance measurements. The method comprises receiving a probe signal and based on the probe signal, determining one of more of: an estimated transverse conversion loss (TCL) coupling transfer function and an estimated transverse conversion transfer loss (TCTL) coupling transfer function.
Various systems and methods are described for performing fractionally spaced time domain equalization (TEQ). One embodiment is a method implemented in a communication system for training a fractionally spaced time domain equalizer (TEQ). The method comprises performing an initialization phase, averaging a received signal in the system to reduce effects of noise in a channel, determining a channel estimate, and aligning an ideal reference signal with the received signal. The method further comprises updating a target response filter according to a non-integer multiple of a base sampling rate, determining an adaptation error based on useful information both inside and outside a Nyquist band of the TEQ, and updating the TEQ according to the adaptation error.
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.
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.
H04B 1/38 - Émetteurs-récepteurs, c.-à-d. dispositifs dans lesquels l'émetteur et le récepteur forment un ensemble structural et dans lesquels au moins une partie est utilisée pour des fonctions d'émission et de réception
62.
Systems and methods for MIMO precoding in an xDSL system
One embodiment is a method for precoding data for transmission in a discrete multi-tone (DMT) system to cancel self-induced far end crosstalk (self-FEXT). The method comprises learning, by the system, characteristics associated with a plurality of N users within a digital subscriber line (xDSL) system to determine an initial off-diagonal multiple input multiple output (MIMO) precoder (ODMP) for a given tone frequency and converging towards an ODMP from the initial ODMP to cancel self-FEXT for the plurality of N users, wherein the ODMP is represented as a zero diagonal matrix containing only off-diagonal terms.
H04L 27/28 - Systèmes utilisant des codes à fréquences multiples à émission simultanée de fréquences différentes, chacune représentant un élément de code
Various embodiments are described for back channel communication. One embodiment is a method that comprises receiving data at customer premises equipment (CPE), determining at least one error in the received data, formatting the determined error for communication to a central office (CO), and sending the formatted error to the CO via a back channel, wherein the formatted error is sent between sync frames of a discrete multitone (DMT) superframe.
G06F 11/00 - Détection d'erreursCorrection d'erreursContrôle de fonctionnement
G01R 31/28 - Test de circuits électroniques, p. ex. à l'aide d'un traceur de signaux
H04B 1/38 - Émetteurs-récepteurs, c.-à-d. dispositifs dans lesquels l'émetteur et le récepteur forment un ensemble structural et dans lesquels au moins une partie est utilisée pour des fonctions d'émission et de réception
INDIAN INSTITUTE OF TECHNOLOGY DELHI DEPARTMENT OF ELECTRICAL ENGINEERING (Inde)
Inventeur(s)
Biyani, Pravesh
Alloin, Laurent Francis
Prakriya, Shankar
Prasad, Surendra
Abrégé
A method implemented in a multi-user communication system is described for performing far-end crosstalk (FEXT) cancellation for each victim user. The method comprises performing dynamic programming to allocate resources according to (N−1) normalized disturber coupling values and difference rate function values associated with N total users in the system involved in partial FEXT cancellation. In accordance with some embodiments, dynamic programming comprises selecting a tone and one or more disturbers to be cancelled for the tone.
A vectored DSL system reduces or eliminates correlated alien interference in active DSL lines in the vectored system by collecting pseudo signals from inactive lines that do not carry upstream DSL transmissions and/or from common-mode voltage signals from active lines. The collected pseudo signals contain in-domain interference, such as FEXT interference from the active DSL lines in the vectored system, and correlated alien interference. After removing the in-domain interference from the pseudo signals, the remaining alien interference data can be used to generate FEXT cancellation coefficients or the like that are used in DSL vectoring to remove the correlated alien interference from upstream DSL user signals from the active DSL lines. The generated FEXT cancellation coefficients are used in a manner analogous to in-domain FEXT data collected from the active lines during training, tracking, etc. The vectored DSL system can include modems coupled to a private vectoring data routing apparatus to one or more vectoring modules The vectoring modules can employ vector processors that include processing units configured to process collected user data on the basis of all modems' data for a given DSL tone grouping, thus removing FEXT effects from the user data and returning vectored user data to the modems using the routing apparatus, which can be a specialized data transmission network utilizing one or more vector routers.
H04B 1/38 - Émetteurs-récepteurs, c.-à-d. dispositifs dans lesquels l'émetteur et le récepteur forment un ensemble structural et dans lesquels au moins une partie est utilisée pour des fonctions d'émission et de réception
H04L 5/16 - Systèmes semi-duplexCommutation duplex-simplexTransmission de signaux de rupture
A reduced-memory vectored DSL system includes methods and apparatus for reducing the bandwidth and memory storage demands on a vectored DSL system in which FEXT data is transmitted and stored. An upstream-end device such as a DSLAM communicates with a plurality of downstream-end devices such as CPE modems. When test signal data, such as training and/or tracking data, is sent to determine FEXT characteristics of the DSL system, error signals are available for all or substantially all of the upstream and/or downstream frequency band DSL tones used in the system. Dividing a frequency band into sub-bands, only a subset of tones in each sub-band is used for deriving FEXT data, such as a FEXT channel response, FEXT channel coefficients and/or FEXT cancellation coefficients. For tones in the sub-band subsets, full-precision FEXT data values can be derived. For other tones, approximations of the FEXT data can be derived.
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.
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.
H03B 1/00 - PRODUCTION D'OSCILLATIONS, DIRECTEMENT OU PAR CHANGEMENT DE FRÉQUENCE, À L'AIDE DE CIRCUITS UTILISANT DES ÉLÉMENTS ACTIFS QUI FONCTIONNENT D'UNE MANIÈRE NON COMMUTATIVEPRODUCTION DE BRUIT PAR DE TELS CIRCUITS Détails
70.
Method and apparatus for data transmission in home networks
A multi-tone modem with components forming a transmit path and a receive path configured to couple to a wired communication medium for at least intermittent communication of frequency division multiplexed multi-tone modulated communication channels thereon. A Fourier transform component transforms received communication channels between a time domain and a frequency domain and vice-versa. Selected components on the receive path determine alignments between the received multiplexed communication channels in the time domain using alignment determinations made in both a time domain and frequency domain portions of the receive path. The Fourier transform component transforms a stream of digitized samples of the received multiplexed communication channels from the time to the frequency domain using the alignment determinations made by the selected components on the receive path. In another embodiment of the invention the multi-tone modem includes a scheduler which optimizes bandwidth allocation on the wired communication medium.
A multi-tone modem with components forming a transmit path and a receive path configured to couple to a wired communication medium for at least intermittent communication of frequency division multiplexed multi-tone modulated communication channels thereon. A Fourier transform component transforms received communication channels between a time domain and a frequency domain and vice-versa. Selected components on the receive path determine alignments between the received multiplexed communication channels in the time domain using alignment determinations made in both a time domain and frequency domain portions of the receive path. The Fourier transform component transforms a stream of digitized samples of the received multiplexed communication channels from the time to the frequency domain using the alignment determinations made by the selected components on the receive path. In another embodiment of the invention the multi-tone modem includes a scheduler which optimizes bandwidth allocation on the wired communication medium.
H04B 1/38 - Émetteurs-récepteurs, c.-à-d. dispositifs dans lesquels l'émetteur et le récepteur forment un ensemble structural et dans lesquels au moins une partie est utilisée pour des fonctions d'émission et de réception
72.
Method and apparatus including a driver for driving a floating bipolar switch
A switch for switchably coupling a signal source to a high impedance load. The switch includes a first bipolar transistor and a floating switch driver. The first bipolar transistor is configured to switchably couple the signal source to the high impedance load responsive to a driver signal applied to a base thereof. The floating switch driver has a control input and an output terminal coupled to the base of the first bi-polar transistor to supply the driver signal thereto. The driver signal comprises a limited forward current during the “On” state of the floating switch driver and a voltage “Voff” not less than the reverse breakdown voltage nor greater than the forward voltage drop across a base-emitter connection of the first bipolar transistor during the “Off” state of the floating switch driver.
A multi-tone modem with shared and discrete components forming a transmit path and a receive path configured to couple to a wired communication medium to communicate at least one multi-tone modulated communication channel thereon. The modem includes a multi-tone modulator component and a configurable frequency up converter component. The multi-tone modulator component is configured for multi- tone modulation and demodulation of a transmitted and received communication channel at a base band frequency range. The configurable frequency up converter component is coupled to the multi-tone modulator to selectably up convert the frequency range of the transmitted base band signal from the multi-tone modulator to that of a selected communication band and down convert received signals from the selected communication band to the base band for demodulation by the multi-tone modulator.
H04B 1/38 - Émetteurs-récepteurs, c.-à-d. dispositifs dans lesquels l'émetteur et le récepteur forment un ensemble structural et dans lesquels au moins une partie est utilisée pour des fonctions d'émission et de réception
74.
Systems and methods for signaling for vectoring of DSL systems
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.
A transceiver having shared and discrete components forming a transmit path and a receive path configured to couple to a subscriber line for establishing a communication channel with a remote transceiver. The transceiver comprises a pseudo link manager coupled between the transmit and receive path components to manage pseudo links on the subscriber line prior to entry into a session with the remote transceiver. The pseudo link manager includes: a line monitor and a disruptor. The line monitor monitors the subscriber line, prior to initiating a session, for a received communication signal indicative of a pre-existing session on the remote transceiver. The disruptor transmits a disruptor signal over the subscriber line to the remote transceiver responsive to the detection by the monitor of the received communication signal; thereby disrupting the remote transmitter's pre-existing session and allowing a new session to be established with the remote transceiver.
A transceiver with a plurality of components coupled to one another to form a transmit path and a receive path for multi-tone modulation of user data across a communication medium. The transceiver includes a framer and a deframer. The framer is configured to momentarily suspend framing of user data before processing bits associated with tones targeted for reference data transport and injects the pre- agreed reference pattern therein, after which framing of user data resumes. The deframer is configured to momentarily suspend deframing of received user data bits before processing bits associated with tones targeted for transport of pre-agreed reference data and extracts the received reference bits thereof for comparison with the corresponding pre-agreed reference bits to determine errors therein, after which deframing of user data resumes.
Included are embodiments for back channel communication. At least one embodiment of a method includes receiving data at customer premises equipment and determining at least one error in the received data. Some embodiments include formatting the determined error for communication to a central office and sending the formatted error to the central office via a back channel.
G06F 11/00 - Détection d'erreursCorrection d'erreursContrôle de fonctionnement
G01R 31/28 - Test de circuits électroniques, p. ex. à l'aide d'un traceur de signaux
H04B 1/38 - Émetteurs-récepteurs, c.-à-d. dispositifs dans lesquels l'émetteur et le récepteur forment un ensemble structural et dans lesquels au moins une partie est utilisée pour des fonctions d'émission et de réception
A line card including: a co-channel estimator and a code selector. The line card is configured to couple to digital subscriber lines to support multi-tone modulation of communications channels thereon. The co-channel estimator is configured to estimate co-channel crosstalk coupling coefficients among selected pairs of the subscriber lines at levels for which the total crosstalk into a selected victim line among the plurality of digital subscriber lines substantially corresponds to the sum of the products of the corresponding crosstalk coupling coefficient for each remaining disturber one of the plurality of subscriber lines and a corresponding substantially unique vector transmitted thereon. The code selector couples to the co- channel estimator. The code selector is configured to select a cross-talk estimation code type and to generate substantially unique code vectors derived there from for injection into selected ones of the of subscriber lines.
A XDSL line card including an allocator for allocating power to the multi-tone modulated communications on each of the subscriber lines, and for selecting control parameters sufficient to effect communications on each of the subscriber lines at a power level proximate to an allocated power level therefore. The line card also includes configurable components coupled to one another to form a transmit path and a receive path to couple to the digital subscriber lines. The configurable components are responsive to the control parameters selected by the allocator to initialize multi- tone communications over each of the plurality of subscriber lines at a power level proximate the allocated power level.
A multi-tone transceiver including: a channel controller and a plurality of components forming a transmit path and a receive path. The channel controller configured to determine bit-loading for each successive symbol or tone set based on a 1st noise margin target for a first subset of tones in each tone set dedicated to transport of a robust communications channel (RCC) and based on a 2nd noise margin target less than the 1st noise margin target for remaining tones in each tone set dedicated to a standard communications channel (SCC). The plurality of components forming the transmit and receive paths are responsive to the channel controller to select for data modulated on a given tone at least one of smaller constellations and higher gain scaling levels when the given tone corresponds to an RCC tone as compared to an SCC tone, whereby the first set of tones dedicated to the RCC exhibit greater immunity to noise variations than the remaining tones dedicated to the SCC.
st noise margin target for remaining tones in each tone set dedicated to a standard communications channel (SCC). The plurality of components forming the transmit and receive paths are responsive to the channel controller to select for data modulated on a given tone at least one of smaller constellations and higher gain scaling levels when the given tone corresponds to an RCC tone as compared to an SCC tone, whereby the first set of tones dedicated to the RCC exhibit greater immunity to noise variations than the remaining tones dedicated to the SCC.
H04B 1/38 - Émetteurs-récepteurs, c.-à-d. dispositifs dans lesquels l'émetteur et le récepteur forment un ensemble structural et dans lesquels au moins une partie est utilisée pour des fonctions d'émission et de réception
82.
Systems and methods for MIMO precoding in an xDSL system
Systems and methods for off-diagonal MIMO precoders are described. At least one embodiment includes a method for precoding data for transmission in a discrete multi-tone (DMT) xDSL system to cancel self-induced far end crosstalk (self-FEXT) comprising: learning characteristics associated with a plurality of N users within the xDSL system to determine an initial off-diagonal multiple input multiple output (MIMO) precoder (ODMP) for a given tone frequency; and converging towards an optimum ODMP from the initial ODMP in order to cancel downstream self-FEXT for the plurality of N users, wherein the ODMP is represented as a zero diagonal matrix with only off-diagonal terms, and wherein the converging towards the optimum ODMP comprises: maximizing the channel capacity for the plurality of N users for the given tone frequency; and minimizing an increase in transmit power of the xDSL system relative to an original transmit power where a precoder is not active.
H04L 27/28 - Systèmes utilisant des codes à fréquences multiples à émission simultanée de fréquences différentes, chacune représentant un élément de code
A two-chip/single-die switch architecture and a method for accessing a DDR SDRAM memory store in a switching environment are presented. The two-chip/single-die architecture includes an internal memory storage block on the single-die, an external memory storage interface to a Double Data Rate Synchronous Dynamic Random Access Memory (DDR SDRAM), an external memory manager, and a packet data transfer engine effecting packet data transfers between an internal memory store and the external DDR SDRAM memory. The packet data transfer engine operates as an adaptation layer addressing issues related to employing appropriate: addressing schemes, granule sizes, memory transfer burst sizes, access timing, etc. The packet data transfer engine includes a minimal number of dual mode operational blocks such as: a queue manager, and adaptation receive and transmit blocks. The method relates to a packet data transfer discipline addressing random memory access latencies incurred in employing DDR SDRAM, using predictive bank switching to hide random access latencies, packet length dependent variable memory write burst lengths to minimize bank switching, and performing memory read and write operations during corresponding read and write windows. Advantages are derived from the a space-efficient two-chip/single-die switching node architecture implemented with a reduced amount of dual mode logic, and also from DDR SDRAM bandwidth utilization efficiencies.
H04L 12/28 - Réseaux de données à commutation caractérisés par la configuration des liaisons, p. ex. réseaux locaux [LAN Local Area Networks] ou réseaux étendus [WAN Wide Area Networks]
A system and method for encoding information is disclosed. In one embodiment, information is encoded using a high protection code for the least significant bit and a low protection code for the next three most significant bits. The remaining bits are uncoded. The high protection code may be a turbo code and the low protection code may be a trellis coded modulation code. In this embodiment, the collection of bits is then mapped according to a diagonally shifted QAM constellation technique.
H03M 13/00 - Codage, décodage ou conversion de code pour détecter ou corriger des erreursHypothèses de base sur la théorie du codageLimites de codageMéthodes d'évaluation de la probabilité d'erreurModèles de canauxSimulation ou test des codes
85.
Method and system for mitigating Fourier transform side lobes
The present invention is directed to implementing theoretical foundations of frequency domain methods aiming to locally decrease the impact of aggregate side lobes of a few discrete frequency tones, in the vicinity of other “victim” frequencies. The family of frequency methods referred to makes use of one or more “canceller tones.” The “canceller tones” loads are optimized to minimize the aggregate power in the neighborhood of the victim frequencies. An exemplary method for decreasing an impact of aggregate side lobes of one or more discrete frequency tones in the vicinity of one or more victim tones comprises the steps of calculating an aggregate power of one or more side lobes of one or more disturber tones within a victim bandwidth; determining at least one optimal load to minimize the aggregate power wherein the at least one optimal load comprises a linear combination of the one or more disturber tones; and applying the at least one optimal load to one or more canceller tones for minimizing the impact of the one or more side lobes of the one or more disturber tones.
H04B 1/38 - Émetteurs-récepteurs, c.-à-d. dispositifs dans lesquels l'émetteur et le récepteur forment un ensemble structural et dans lesquels au moins une partie est utilisée pour des fonctions d'émission et de réception
H04B 3/20 - Réduction des effets d'échos ou de sifflementSystèmes à ligne de transmission Détails ouverture ou fermeture de la voie d'émissionCommande de la transmission dans une direction ou l'autre
H04M 9/08 - Systèmes téléphoniques à haut-parleur à double sens comportant des moyens pour conditionner le signal, p. ex. pour supprimer les échos dans l'une ou les deux directions du trafic
86.
Minimum processor instruction for implementing weighted fair queuing and other priority queuing
The present invention provides techniques for efficiently determining a minimum or maximum of a plurality of values and the index of the minimum using registers of a processor. The present invention also provides for various processor instructions for determining the minimum/maximum and index of two or more values. The present invention finds particular benefit in implementing heaps and in systems utilizing Weighted Fair Queuing (WFQ).
brevets
