Patent application number | Description | Published |
20090059780 | METHOD AND APPARATUS FOR SELF-TUNING PRECODER - Techniques are disclosed for compensating for crosstalk using adaptation of data signals transmitted over respective channels of a communication system. For example, a method includes the following steps. A first set of estimated measures of crosstalk is obtained for at least a selected portion of a plurality of communication channels over which data signals are to be transmitted from a transmitter to at least a selected portion of a plurality of receivers. A first set of data signals based on the first set of estimated measures of crosstalk is adapted to generate a first set of adjusted data signals. The first set of adjusted data signals is transmitted to corresponding ones of the plurality of receivers. A second set of estimated measures of crosstalk is obtained for the selected portion of the plurality of communication channels. A second set of data signals for transmission based on the second set of estimated measures of crosstalk is adapted to generate a second set of adjusted data signals. Iteration of the obtaining, adjusting and transmitting steps is performed so as to reduce an error between subsequent estimated measures of crosstalk and actual measures of crosstalk for the plurality of communication channels. | 03-05-2009 |
20090109856 | SYSTEM AND METHOD FOR REDUCING SWITCHING OVERHEAD IN A COMMUNICATION NETWORK - A system and method for reducing switching overhead in a communication network and a web-based server incorporating the system or the method. In one embodiment, the system includes: (1) an optimization engine configured to receive input data describing trunks, switches and traffic demands in at least a portion of the communication network and arrange connections between the trunks and switches such that the traffic demands are satisfied and such that a switch load or cost is reduced and (2) a report generator associated with the optimization engine and configured to produce a report containing a modified configuration having the reduced switch load or cost. | 04-30-2009 |
20090310502 | Device and associated method for crosstalk estimation - The present invention relates to a crosstalk estimation device for estimating crosstalk between communication lines in a precoding group. The crosstalk estimation device comprises transmission means for transmitting a pilot sequence and reception means for receiving error feedback on one or more communication lines in the precoding group. The crosstalk estimation device further comprises crosstalk estimation means for combining the pilot sequence with the error feedback in order to obtain a crosstalk estimation between the communication lines. The device further comprises selection means for selecting a subset of one or more communication lines from the precoding group. The transmission means are adapted to transmit the pilot sequence only on the subset. | 12-17-2009 |
20100046355 | Communication system for improved cross talk estimation and method thereof - The present invention relates to a communication system for improved crosstalk estimation and method thereof. The communication system may include a vectoring group and a central office. The vectoring group includes a plurality of first communication lines and at least one second communication line. The plurality of first communication lines is a different type of communication line from the at least one second communication line. The central office is configured to assign the pilot sequences to each communication line within the plurality of first communication lines according to a first constraint. The central office is also configured to delay sending a sync flag in response to a request until a flag sequence of the at least one second communication line satisfies a second constraint. The assigned pilot sequences and sent flag sequences are orthogonal to each other based on the first and second constraints. | 02-25-2010 |
20100046684 | Communication system for transmitting sync-flags and pilot symbols and method thereof - The present invention relates to a communication system and method for transmitting sync flags and pilot symbols during sync symbol periods. Example embodiments provide a method for sharing sync symbols to communicate flag sequences and pilot sequences during a sequence of sync symbol periods. The method includes modulating the pilot sequence by multiplying a pilot code by each value of the pilot sequence, and modulating the flag sequence by multiplying a flag code by each value of the flag sequence. The pilot and flag codes are mutually orthogonal to each other and each includes at least two non-zero values. The method further includes generating a resulting sync symbol sequence based on the modulated pilot sequence and modulated flag sequence, and sending the resulting sync symbol sequence during the sync symbol period. | 02-25-2010 |
20120082258 | CHANNEL ESTIMATION UTILIZING CONTROL SIGNALS TRANSMITTED BY AN ACTIVATING LINE DURING INITIALIZATION - An access node of a communication system is configured to control crosstalk between an activating channel associated with a first network terminal of a communication system and active channels associated with respective other network terminals of the system. The access node detects a control signal sent by the first network terminal over the activating channel in a designated phase of an initialization process of the first network terminal, determines an error signal from the detected control signal, correlates the error signal with one or more corresponding signals sent by respective ones of the other network terminals over the active channels, estimates crosstalk from the active channels into the activating channel based on the correlation, and configures a vectoring signal processing module to control the estimated crosstalk. The control signal sent by the first network terminal comprises a value that is selected by the first network terminal from a set of two or more values and prior to its detection the particular selected value is unknown to the access node. | 04-05-2012 |
20120195183 | MULTIPLICATIVE UPDATING OF PRECODER OR POSTCODER MATRICES FOR CROSSTALK CONTROL IN A COMMUNICATION SYSTEM - An access node of a communication system is configured to control crosstalk between channels of the system. Vectoring circuitry in the access node estimates crosstalk between channels of the system, generates a compensation matrix based on the crosstalk estimates, and generates compensated signals based on the compensation matrix. The compensation matrix, which may be a precoder matrix or a postcoder matrix, is generated using a multiplicative update process in which a previous version of the compensation matrix comprising one or more non-zero off-diagonal elements is updated by at least one of pre-multiplying by a first auxiliary matrix and post-multiplying by a second auxiliary matrix, with a given one of the auxiliary matrices also comprising one or more non-zero off-diagonal elements. The compensated signals may be pre-compensated signals or post-compensated signals. | 08-02-2012 |
20120236915 | CROSSTALK CONTROL METHODS AND APPARATUS UTILIZING COMPRESSED REPRESENTATION OF COMPENSATION COEFFICIENTS - An access node of a communication system is configured to control crosstalk between channels of the system. Vectoring circuitry in the access node is configured to determine estimates of crosstalk from one channel of the system into another channel of the system on multiple sub-channels, to determine compensation coefficients for respective ones of the multiple sub-channels based on the crosstalk estimates, and to generate compensated signals for respective ones of the multiple sub-channels based on the compensation coefficients. At least a given one of the compensation coefficients is determined for use in the generation of compensated signals by decompressing a compressed representation of the given compensation coefficient. The compressed representation is decompressed by evaluating a parameterized function of a plurality of control parameters at least one of which does not correspond to any of the compensation coefficients. The compensated signals may be pre-compensated signals or post-compensated signals. | 09-20-2012 |
20140205082 | METHODS AND SYSTEMS FOR REDUCING CROSSTALK - At least one example embodiment discloses a method of reducing crosstalk interference in a system having a plurality of communication paths. The method includes obtaining a plurality of signal values corresponding to a set of active communication paths, the active communication paths being a subset of the plurality of communication paths, obtaining an inverse channel matrix, the inverse channel matrix representing an inverse crosstalk channel matrix of the system when the plurality of communication paths in the system are active, determining a plurality of sub-matrices from the inverse channel matrix based on the set of active communication paths and compensating the signal values for crosstalk by individually applying at least one of the sub-matrices to the plurality of signal values. | 07-24-2014 |
Patent application number | Description | Published |
20090060013 | OPTIMIZING PRECODER SETTINGS USING AVERAGE SINR REPORTS FOR GROUPS OF TONES - Techniques are disclosed for compensating for crosstalk using adaptation of data signals transmitted over respective channels of a communication network. In one example, a method comprises the following steps. Data is transmitted to a communication network device via a communication line during a sequence of periods. For each period of the sequence of periods, a separate value of a measure of crosstalk that was measured at the communication network device is received, each value being an average of measurements at the device of measures of crosstalk for a plurality of communication network signal subcarriers. For each individual signal subcarrier of the plurality, a matrix is updated based on the received values, the matrix being configured to precode data transmissions to the communication network device over the individual signal subcarrier. The communication network may be a DSL system, the signal subcarriers may be DSL tones, and the measure of crosstalk may be a SINR value. | 03-05-2009 |
20090245081 | Fast Seamless Joining of Channels in a Multi-Channel Communication System - At least one channel is joined to a group of active channels in a communication system by transmitting control signals to configure respective customer premises equipment (CPE) of the active channels into a joining mode of operation, and transmitting a joining signature sequence to CPE of the joining channel over a downstream data signal path of the joining channel. A central office (CO) or other access node of the system receives correlation results from respective active channel CPE, estimates crosstalk from the joining channel into the active channels based on the correlation results, configures a precoder based on the estimated crosstalk, and adds the joining channel to the group of active channels. The channels may comprise respective subscriber lines of a DSL communication system. | 10-01-2009 |
20090304056 | Signal suspension and resumption in DSL systems - A method includes maintaining temporally parallel DSL data communication sessions with DSL modems of a group via a set of lines. The method includes, in response to substantially stopping to receive DSL communications from one of the DSL modems via one of the lines, transmitting a substantially reduced average power to the one of the lines and monitoring the one of the lines to determine whether DSL communications have restarted being received from the one of the DSL modems. The method also includes resuming the maintaining of the temporally parallel DSL communication sessions in response to the monitoring determining that DSL communications have restarted being received from the one of the DSL modems. | 12-10-2009 |
20100021165 | OPTICAL TELECOMMUNICATIONS NETWORK AND METHOD - An optical communications network architecture and associated method which employs time and wavelength-interleaving for homing between nodes/satellites and hubs and for grooming, while employing wavelength-division-multiplexed wavelength circuits between hubs without requiring cross-connects or routers therebetween. | 01-28-2010 |
20100202281 | Simultaneous Estimation of Multiple Channel Coefficients Using a Common Probing Sequence - An access node of a communication system comprises a plurality of transmitters adapted for communication with at least one receiver. The access node is operative to simultaneously estimate channel coefficients between multiple ones of the transmitters and the receiver, and to utilize the estimated channel coefficients to control at least one data signal sent by at least one of the multiple transmitters to the receiver. In the process of simultaneously estimating the channel coefficients, the access node transmits a plurality of distinct probing signals, each of which is generated based on a distinct combination of a common probing sequence and a selected one of a plurality of different frequency expansions. The access node may comprise at least a portion of at least one central office of a DSL communication system. | 08-12-2010 |
20100202554 | SIMULTANEOUS ESTIMATION OF MULTIPLE CHANNEL COEFFICIENTS USING A COMMON PROBING SEQUENCE - An access node of a communication system comprises a plurality of transmitters adapted for communication with at least one receiver. The access node is operative to simultaneously estimate channel coefficients between multiple ones of the transmitters and the receiver, and to utilize the estimated channel coefficients to control at least one data signal sent by at least one of the multiple transmitters to the receiver. In the process of simultaneously estimating the channel coefficients, the access node transmits a plurality of distinct probing signals generated based on respective ones of a plurality of different frequency expansions. For example, each of the distinct probing signals may be generated based on a distinct combination of a common probing sequence and a selected one of the plurality of different frequency expansions. | 08-12-2010 |
20100278222 | Validated signal resumption in DSL systems - An apparatus includes a DSL transceiver configured to transit to a DSL wait state in which a power transmitted from the DSL transceiver to a local-end line is substantially reduced in response to an interruption or substantial stop at the DSL transceiver of reception of DSL communications from the local-end line. The DSL transceiver is configured to transmit to the local-end line a DSL acknowledge signal in response to receiving from the local-end line a DSL wait signal. The DSL transceiver is configured to resume to transmit DSL communications to the local-end line at a power substantially higher than the power transmitted thereto in the DSL wait state in response either to receiving from the local-end line DSL transmissions at a substantially higher power than received there from in the DSL wait state or to receiving from the local-end line a second DSL acknowledge signal. | 11-04-2010 |
20110193447 | Stable Electro-Mechanical Actuators - An electro-mechanical actuator includes a comb drive and a deformable connector. The comb drive has a first capacitor plate and a second capacitor plate. The capacitor plates have teeth capable of inter-digitating. The deformable connector is configured to apply a mechanical restoring force to the first capacitor plate. The deformable connector is configured to restore the first capacitor plate to be at an equilibrium rest position in response to no control voltage being applied across the capacitor. The comb drive is more engaged at the equilibrium rest position than at a mechanical stability threshold of the comb drive. The capacitor plates are disengaged at the equilibrium rest position. | 08-11-2011 |
20110193502 | Stable Electro-Mechanical Actuators - An electro-mechanical actuator includes a comb drive and a deformable connector. The comb drive has a first capacitor plate and a second capacitor plate. The capacitor plates have teeth capable of inter-digitating. The deformable connector is configured to apply a mechanical restoring force to the first capacitor plate. The deformable connector is configured to restore the first capacitor plate to be at an equilibrium rest position in response to no control voltage being applied across the capacitor. The comb drive is more engaged at the equilibrium rest position than at a mechanical stability threshold of the comb drive. The capacitor plates are disengaged at the equilibrium rest position. | 08-11-2011 |