Abstract: A noise cancellation system has a first transformer with an input side and an output side, the input side having first and second taps coupled to a signal provider, and a center tap providing a first common-mode voltage signal. A first digital subscriber line (xDSL) modem has an input coupled to the output side of the first transformer and an output coupled to customer premises equipment (CPE) for providing an xDSL signal to the CPE. A second transformer has an input side and an output side, the input side having first and second taps coupled to a signal provider, and a center tap providing a second common-mode voltage signal. A second xDSL modem is coupled to the output side of the second transformer. The difference between the first and second common-mode voltage signals is provided to at least one of the first and second xDSL modems to filter out noise from the xDSL signal provided by that modem.

Abstract: A multimedia conferencing system includes a loud speaker system, one or more microphones for receiving a local audio signal and a remote audio signal, a state machine and an echo canceller that operates in conjunction with two reference signals to remove substantially all of a feedback signal component in the local audio signal that results from reinforcing and playing the local audio signal over the loud speaker system. The state machine operates to detect that only the local audio is active, and if so controls the operation of the echo canceller such that only the feedback component of the local audio signal is removed and the local audio signal is not suppressed.

Abstract: A cancellation system is disclosed for processing incoming and outgoing signals in a transform domain to create a cancellation signal for reducing or removing unwanted interference. Data is ordered based on Good-Thomas indexing into a two dimensional array in a buffer. The two dimensional array may have lr rows and lw columns. From the buffer, the columns of data undergo a Winograd small transform. The rows of data undergo a Cooley-Tukey operation to complete the transform operation into the frequency domain. Multipliers scale the transformed data to generate a cancellation signal in the frequency domain. Inverse (Cooley-Tukey) and Winograd transforms perform inverse processing on the cancellation signal to return the cancellation signal or data to the time domain. Re-ordering the data and combination of the cancellation signal or data with incoming or outgoing signals achieve interference cancellation.

Abstract: Methods and systems for interference avoidance in a multi-protocol communication system may comprise receiving signals in a first communications protocol (FCP) in a first frequency range (FFR), configuring channel usage in a second communications protocol (SCP) in a second frequency range (SFR) based on the received signals to control interference from the SFR to the FFR. Signals may be communicated over coaxial cables based on the configuration of channel usage in the SCP in the SFR based on the received signals, such that aliased signals do not excessively degrade performance of the FCP. The FFR may comprise a cable or satellite television frequency range. The FCP may comprise data over cable service interface standard (DOCSIS). The SCP may comprise multimedia over coaxial alliance (MoCA) standard. The configuring channel usage in the SCP may comprise varying bit loading, power levels, or degree of modulation of signals transmitted over the SCP.

Abstract: In an illustrative embodiment, a data interface circuit is provided. The data interface circuit comprises data sources, input blocks, a space switch, output blocks and a multi-core processor. The data interface circuit allows data provided in different voltage ranges and sampling frequencies to be transmitted to the appropriate core in the multi-core processor via the switch. Data conversion elements in the input blocks convert data from the data sources and having varying voltage ranges and sampling frequencies into data having a voltage range and sampling frequency suitable for the space switch. Analogously, data conversion elements in the output blocks convert data from the space switch into data having a voltage range and sampling frequency suitable for the corresponding core in the multi-core processor. In one embodiment, level shifters and FIFO buffers are used in the input blocks and output blocks.

Abstract: Aspects of a method and apparatus for band separation for multiband communication systems are provided. One or more circuits for use in a transceiver may comprise a triplexer and a leakage processing module. The triplexer may comprise a multiband port, a Multimedia Over Coaxial Alliance (MoCA) port, a television upstream port, and a television downstream port. The leakage processing module may comprise a television downstream input port, a cable television downstream output port, a MoCA port, and a cable television upstream port. The leakage processing module may be operable to (1) process a MoCA signal to generate a first compensation signal; (2) process a cable upstream signal to generate a second compensation signal; (3) process a filtered signal based at least in part on the first and second compensation signals; and (4) output the processed filtered signal via the cable television downstream output port of said leakage processing module.

Abstract: A first device receives a first signal transmitted over a transmission line from a second device. The first signal is processed and information is generated that is related to crosstalk from other transmission lines. The information is modulated onto at least one carrier of a plurality of carriers of a second signal to be transmitted from the first device to the second device.

Abstract: A network apparatus for eliminating interference between transport ports includes a plurality of transport ports, a plurality of seed comparators, and a control unit. The plurality of seed comparators are coupled to the plurality of transport ports, respectively, wherein a first seed comparator is utilized for comparing a first seed of a first transport port with a second seed of a second transport port and accordingly generating a comparing result. The controlling unit is coupled to the plurality of seed comparators and the plurality of transport ports, for generating a control signal to cancel interference between the plurality of transport ports according to the comparing result.

Abstract: A method for optimizing resource allocation for signal conditioning of DSL or other signal lines includes developing a signal quality metric using crosstalk interference and, optionally, signal to noise level. Use of existing pilot tone training selectively assigned to signal lines allows determination of the signal quality metric. A threshold level is selected and all signal lines having a signal quality metric above the threshold level are assigned crosstalk cancellation resources. Because the total number of signal lines requiring crosstalk cancellation is not known at the beginning, a particular threshold level may result in allocation of more than the available resources or allocation of significantly less than the available resources. When this happens the threshold level may be adjusted and the process repeated until crosstalk cancellation resources are assigned up to a usable limit.

Abstract: An apparatus for precoding multi-tone modulated transmissions of a plurality of communication channels over bundled subscriber lines. The apparatus includes a pseudo symbol controller and a precoder. The pseudo symbol controller detects a victim communication channel and an interferer communication channel having non-matching symbol rates, and transforms the interferor channel into a pseudo-symbol having both a substantially similar length as a corresponding symbol of the victim channel together with defined tonal characteristics expressed in terms of the interferor channel. The precoder assigns crosstalk coefficients to selected sub-channels or tones of the pseudo symbol and precodes the victim channel with the pseudo symbol using the crosstalk coefficients; thereby generating a precoded victim symbol which exhibits reduced crosstalk between the selected victim and interferor.

Abstract: A method and system are described for canceling far end cross-talk in communication systems. A first transmitter transmits the first effective data source signals across the first channel. A second transmitter transmits the second effective data source signals across the second channel. In one embodiment, a receiver unit receives first and second effective data source signals across a first channel and a second channel, respectively, and also one or more cross-talk signals. A far end cross talk (FEXT) canceller located in the receiver unit receives second estimated effective data source signals based on the second effective data source signals. The receiver unit cancels the one or more cross-talk signals using the second estimated effective data source signals.

Abstract: A wireless transmitter exhibits improved power de-rating reduction, which improves the power efficiency of non-constant envelop communication systems by mapping N first samples of a first discrete Fourier transform (DFT) of a group of coded symbols to M sub-carriers according to a first sub-carrier mapping rule (212), performing a first inverse DFT (IDFT) on the M sub-carriers to provide M second samples (214), clipping the M second samples according to a clipping rule to provide M third samples (216), performing a second DFT on the M third samples (218), and applying a frequency domain mask to generate M clipped samples (220) which may be mapped to O subcarriers according to a predetermined second subcarrier mapping rule. The transmitter may be advantageously implemented within a single carrier transmission scheme, such as a single carrier-frequency division multiple access (SC-FDMA) uplink transmission scheme.

Abstract: A voice packet dynamic echo cancellation system includes an input/output unit configured to communicate over a packet network and a storage unit configured to store network performance information associated with node segments on the packet network. The system also includes a processing unit configured to execute instructions to: set-up a call from an originating call device to a terminating call device; determine the network performance of the call between the originating call device and the terminating call device; locate an echo signal of the call to the originating call device based on the network performance; produce a echo cancellation signal based on the echo signal; cancel the echo signal with the echo cancellation signal; and recheck the network performance information during a duration of the call and adjust the specific delay point of the received signal window based on the network performance information.

Abstract: Methods and system for using a multifunctional filter to minimize insertion loss in a multimode communications system are described. Specifically described is a multifunctional filter that is configurable to operate in a bandpass mode when a first type of signal is propagated through the multifunctional filter, and to operate in a lowpass mode when a second type of signal is propagated through the multifunctional filter. The multifunctional filter presents a lower insertion loss to the second type of signal when operating in the lowpass mode than in the bandpass mode.

Abstract: Typical transceivers have multiple near-end and multiple far-end crosstalk cancellation filters. Crosstalk cancellation is one of the largest contributors to power dissipation in the DSP portion of high speed Ethernet transceivers. By detecting the cable type, a transceiver could automatically turn off its crosstalk cancellation filters when driving shielded twisted pair (STP) cables and substantially reduce the overall power dissipation in this configuration. Adaptive digital crosstalk cancellers automatically adjust the coefficients of a digital filter to match the coupling function between two channels. The impulse response of an optimal crosstalk cancellation filter can be used to determine a metric indicating the amount of coupling between the two channels. STP cables will have a much lower amount of coupling between wire-pairs than unshielded twisted pair cables.

Abstract: A method for managing a channel matrix is provided. The method includes: obtaining whether a user logs on or logs off; adding a history record of channel information of the user to a channel matrix when the user logs on; recording current channel information of the user in the channel matrix and deleting the channel information of the user from the channel matrix when the user logs off. The channel matrix may be timely updated based on when the user logs on or off. Accordingly, the channel crosstalk is eliminated timely and correctly according to the channel matrix, and the affection on the crosstalk eliminating capacity caused by the user logs on or logs off can be avoided.

Abstract: A method and apparatus for providing echo cancellation are disclosed. For example, the method receives via an echo canceller a first audio signal directed towards an endpoint device, and adds an inserted signal to the first audio signal directed towards the endpoint device. The method determines if a second audio signal being received from the endpoint device comprises the inserted signal, and cancels at least a portion of the second audio signal that is associated with the first audio signal, if the inserted signal is detected.

Abstract: A method for reducing cross cell interference in a wireless time division duplex communication system using code division multiple access, the system having at least one user equipment (UE) and a base station (BS) is disclosed. The method begins by measuring an interference level of each timeslot at the BS. A timeslot is eliminated for additional uplink communication if the measured interference level exceeds a first threshold. UEs in nearby cells that are large interferers are identified and their downlink timeslot usage is gathered. A timeslot is eliminated for uplink communication for a large interferer UE that uses the timeslot for downlink communication.

Abstract: A device for determining an information indicating a length of a part of a first cable, the first cable connecting a first transceiver unit and a first subscriber device, wherein the part of the first cable extends from the first transceiver unit to a point of the first cable from where a second cable, which connects a second transceiver unit to a second subscriber device, joins the first cable to extend from the second transceiver unit to the second subscriber device, the device comprising an input to couple the device to the second cable, a first apparatus coupled to the input to measure a quiet line noise related to crosstalk from the first cable to the second cable, and a second apparatus to determine information indicating the length of the part of the first cable based on the quiet line noise.

Abstract: A cancellation system is disclosed for processing incoming and outgoing signals in a transform domain to create a cancellation signal for reducing or removing unwanted interference. Data is ordered based on Good-Thomas indexing into a two dimensional array in a buffer. The two dimensional array may have lr rows and lw columns. From the buffer, the columns of data undergo a Winograd small transform. The rows of data undergo a Cooley-Tukey operation to complete the transform operation into the frequency domain. Multipliers scale the transformed data to generate a cancellation signal in the frequency domain. Inverse (Cooley-Tukey) and Winograd transforms perform inverse processing on the cancellation signal to return the cancellation signal or data to the time domain. Re-ordering the data and combination of the cancellation signal or data with incoming or outgoing signals achieve interference cancellation.

Abstract: A communication system has a trunk extending from a network facility, such as a central office, with a plurality of distribution points positioned along the trunk. Each leg of the trunk defines a shared channel that permits peak data rates much greater than what would be achievable without channel sharing. As an example, the connections of each respective trunk leg may be bonded. Further, the same modulation format and crosstalk vectoring are used for each leg of the trunk. The crosstalk vectoring cancels both far-end crosstalk (FEXT) that couples between connections of a given trunk leg and crossover crosstalk that couples between one trunk leg and another. In addition, logic determines an amount of excess capacity available for each leg of the trunk and controls error correction based on the determined excess capacity.

Abstract: Crosstalk interference induced by the adjacent pairs is one of the major performance limiting factors of DSL systems. As there is a rapid increase in the deployment of DSL services worldwide, the need to provide information about noise related parameters to the operators and the service providers is of utmost importance. Satisfying such a need enables operators to anticipate the line capacity and understand the noise level characteristics of the loop environment. Specifically, crosstalk and more particularly upstream near end crosstalk (NEXT) in the presence of narrowband interference can be classified to isolate the particular service type causing the upstream NEXT. The identification of the service type of the upstream NEXT would enable operators to address the disturber.

Abstract: A receiving system and a method of processing broadcast signal are disclosed herein. The receiving system includes N number of antennae, N number of demodulators, N number of known sequence detectors, and an equalizer. The N number of antennae each receives a broadcast signal including mobile service data and known data sequences. The N number of demodulators demodulates the broadcast signal received by the corresponding antenna. The N number of known sequence detectors detects known data sequences from the broadcast signal received by the corresponding antenna.

Abstract: A network apparatus for eliminating interference between transport ports includes a plurality of transport ports and at least one alien NEXT canceller. The alien NEXT canceller is coupled to a designated transport port of the plurality of transport ports for eliminating NEXT interference from other transport ports of the plurality of transport ports. The alien NEXT canceller operates in a time domain or a frequency domain. In one exemplary embodiment, the network apparatus is a switch.

Abstract: Methods and apparatus are disclosed, such as those involving an inter-chip interface configured to receive and process electronic data. One such interface includes a receiver circuit that includes a clock tree configured to receive a clock signal at a clock tree input. The clock tree distributes a plurality of clock signals delayed from the clock signal such that one or more of the clock signals have a delay different from the delays of the other clock signals. The receiver circuit further includes a plurality of data input latches configured to receive a plurality of data elements over two or more different points in time. This configuration at least partially reduces crosstalk and simultaneous switching output noise.

Abstract: A technique for avoiding reception performance deterioration caused by a tone interference that occurs at a position carrying a pilot signal in a wireless communication system is provided. A receiving end includes an operator for converting a time-axis signal into a frequency-axis signal, an extractor for generating channel values in positions carrying pilot signals among the frequency-axis signals, a compensator for compensating for a channel value of a position at which tone interference occurs by using at least one channel value of a position at which no tone interference occurs among the channel values.

Abstract: A system includes at least one adaptive filter coupled to a first communication channel and at least one other communications channel. The at least one adaptive filter includes at least one set of adaptive filter coefficients. A memory stores at least one predetermined set of filter coefficient thresholds. The filter coefficient thresholds may be indicative of channel faults, channel to channel faults or a length of the channel. A controller is configured to compare the set of filter coefficients to the predetermined set of filter coefficient thresholds. The controller is configured to determine the information about the channels based on compare results.

Abstract: An embodiment of a method and apparatus for determining a change in network-generated crosstalk levels caused by a multi-line phone includes determining a first crosstalk level between a first line pair and a second line pair of a multi-line phone caused by the multi-line phone, and determining a second crosstalk level between each of the first line pair and the second line pair of the multi-line phone. The second crosstalk level is determined when the first line pair and the second line pair are coupled to a first predetermined length of network line pair cable. The method further includes determining a change of network generated crosstalk levels caused by the multi-line phone by subtracting the first crosstalk level from the second crosstalk level.

Abstract: System and methods provide acoustic echo monitoring and cancellation for real time media processing in an internet protocol (IP) media server in an IP network. An echo monitor is configured to selectively compare audio streams into and out of the IP media server through a selected port. The comparison determines an occurrence of an echo. An echo canceller in communication with the echo monitor is configured to respond to the determination by the echo monitor so as to remove the echo from at least one of the audio streams. A talk burst detector may be used to detect speech in at least one of the audio streams through the selected port. The echo monitor selectively compares the audio streams in response to a signal from the talk burst detector that indicates detection of speech.

Abstract: Aspects of a method and system for an extended range copper transceiver are provided. Reducing the communication rate provided by multi-rate physical (PHY) layer operations in an Ethernet transceiver may extend the range of the Ethernet transceiver over twisted-pair copper cabling from a standard connection length. The Ethernet transceiver may support up to 1 Gbps or up to 10 Gbps transmission rate over copper cabling. The multi-rate PHY layer architecture in the Ethernet transceiver may support signal-processing operations, such as echo cancellation and/or equalization, which may be applied to the reduced communication rate to enable range extension. The reduced communication rate may be achieved by reducing the symbol rate provided by the multi-rate PHY layer operations. Reducing the communication rate may also enable utilizing greater insertion loss cabling for a standard connection length.

Abstract: Described are methods and circuits for reducing the error-inducing effects of crosstalk. Communication circuits in accordance with some embodiments adjust the phase of transmitted “aggressor” data to misalign transmitted signals from the perspective of “victim” channels. This misalignment moves the noise artifacts cross coupled to the victim channel away from sensitive sample times in the victim data, and consequently reduces the net effects of aggressor crosstalk on neighboring victim channels. Some embodiments reduce the effects of crosstalk by introducing static timing offsets to one or a plurality of aggressor transmitters, one or a plurality of victim transmitters, or some combination of aggressor and victim transmitters. Other embodiments dynamically alter the relative timing of aggressor and victim transmitters.

Abstract: A method and a device are provided for crosstalk evaluation of a channel, wherein the channel is represented and/or modeled by a multiple-input-multiple-output (MIMO) system connecting a first network component with at least one second network component. The MIMO system contains first coefficients associated with transmission lines that are in particular associated with crosstalk. The crosstalk contains a near-end crosstalk (NEXT) portion and a far-end crosstalk (FEXT) portion. The first network component sends a signal to one second network component; the far-end crosstalk portion and the near end crosstalk portion are evaluated.

Abstract: 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.

Abstract: A method, central unit, and modem for reducing crosstalk in a Digital Subscriber Line (DSL) system. A virtual line referred to as a ghost line is introduced in the system as a substitution for all of the lines except a first line to induce crosstalk to the first line. The Power Spectral Density (PSD) on the first line is allocated to optimize against the ghost line. A modem on the first line reports to a central Spectrum Management Center (SMC), a measure indicating crosstalk impact from the ghost line. This process is repeated for each line. The SMC calculates updated ghost line parameters for each line, which reflect current crosstalk characteristics between each modem and the remaining modems, and sends the updated parameters to the modems. The modems then reallocate PSDs with respect to the updated ghost line parameters to either maximize the rate or minimize the power on their respective lines.

Abstract: A method for remote crosstalk cancellation, includes: filtering, at a first transmitting end which is connected to a first receiving end over a first line, crosstalk source signals according to values of filtering parameters; synthesizing, at the first transmitting end, a first signal to be transmitted over the first line and the filtered crosstalk source signals; transmitting the synthesized signal from the first transmitting end to the first receiving end over the first line; receiving, at the first transmitting end, a noise statistic related value fed back from the first receiving end; and adjusting, at the transmitting end, the values of the filtering parameters according to the noise statistic related value. A corresponding device and a signal processing system for remote crosstalk cancellation are provided.

Abstract: Aspects of a method and system for a programmable interference suppression module may include receiving a communication signal comprising one or more desired signal, and one or more undesired signals. The communication signal may be utilized to generate estimated channel state information. The estimated channel state information may be formatted for use in interference suppression. A reduced interference signal may be generated from a delayed version of said communications signal and the estimated channel state information, wherein the one or more undesired signals may be attenuated. The reduced interference signal may be formatted for post-processing. The desired signals may comprise WCDMA and/or HSDPA signals, and the undesired signals may be inter-cell and/or intra-cell interference. Further processing may comprise HSDPA processing and/or RAKE finger processing. The communication signal may be a Universal Mobile Telecommunication System (UMTS) compliant signal.

Abstract: Typical transceivers have multiple near-end and multiple far-end crosstalk cancellation filters. Crosstalk cancellation is one of the largest contributors to power dissipation in the DSP portion of high speed Ethernet transceivers. By detecting the cable type, a transceiver could automatically turn off its crosstalk cancellation filters when driving shielded twisted pair (STP) cables and substantially reduce the overall power dissipation in this configuration. Adaptive digital crosstalk cancellers automatically adjust the coefficients of a digital filter to match the coupling function between two channels. The impulse response of an optimal crosstalk cancellation filter can be used to determine a metric indicating the amount of coupling between the two channels. STP cables will have a much lower amount of coupling between wire-pairs than unshielded twisted pair cables.

Abstract: A system for scaling vectored DSLAM deployments has a DSLAM interfaced with a cross-connect apparatus. The DSLAM receives POTS signals from at least one bridge connection assembly. When a DSLAM is added at the cross-connect facility, at least one connector of the bridge connection assembly is disconnected from an existing DSLAM and is interfaced with the newly-added DSLAM. By moving the connector to the newly-added DSLAM, a batch of downstream distribution pairs (which are preferably bound by a single distribution cable) are effectively moved from the existing DSLAM to the new DSLAM without having to reconfigure the jumpers of the cross-connect apparatus. Accordingly, it is possible to scale the cross-connect facility to any number of vectored DSLAMs while limiting vector group sizes, thereby reducing the complexity of vectoring operations, without having to perform complex reconfigurations of the cross-connect apparatus.

Abstract: A communication system comprises a plurality of line cards having transceivers coupled to a plurality of subscriber lines. Each line card has at least one active transceiver within the same vectoring group, and each line card also has vector logic capable of cancelling crosstalk induced by an active transceiver that is a member of the vectoring group. Further, the line cards are coupled to one another via a ring connection across which vectoring information is passed from one line card to the next. In the event of a failure of one of the line cards, the failed card is bypassed by the vectoring stream so that the operational line cards can continue crosstalk vectoring operations despite such failure.

Abstract: A communication system comprises a plurality of line cards having transceivers coupled to a plurality of subscriber lines. Each line card has at least one transceiver within the same vectoring group, and each line card also has vector logic capable of cancelling crosstalk induced by a tone communicated by any member of the vector group. Further, the line cards are coupled to one another via a data connection across which a vectoring stream carrying vectoring information from one line card to the next. The bandwidth of the vectoring stream is reduced by dynamically adjusting time slots of the vectoring stream based on bit loading for the communicated tones.

Abstract: Methods and apparatus describe techniques for reducing interference signals in a communication signal. An apparatus includes, in at least one aspect, a transceiver circuit to receive a communication signal that includes one or more interference signals and a compensation circuit to generate a compensation signal to compensate for the one or more interference signals in the communication signal based on one or more cancellation coefficients and one or more data symbols.

Abstract: Example embodiments are directed to a system for simulating far end crosstalk (FEXT). The system includes digital subscriber lines coupled to a FEET matrix which simulates the FEXT environment. The FEXT matrix simulates the FEXT environment using filters disposed in disturber lines. Signals output from the filters are added to a path in the victim line to create an output signal.

Abstract: A method and apparatus for eliminating receive band noise in a communication system is provided. The method comprises sensing a transmit signal at a receive frequency, wherein the signal sensed is a bleed over signal from a transmit signal. The sensed bleed over signal is then digitized using a secondary receiver. This secondary receiver utilizes a separate path from the primary receive path. The next step in the method is to estimate the linear distortion, delay, attenuation in the sensed bleed over signal. Next, compensation for the linear distortion, delay, and attenuation are performed on the sensed bleed over signal. The sensed, digitized, and compensated bleed over signal is then cancelled from the primary receive path.

Abstract: Systems and methods for power line transmission are disclosed in which transmitters and receivers are connected to one or more phases of the power line. At least one symbol stream to be transmitted on the power line network is generated. The at least one symbol stream is scaled using a weight vector to generate a plurality of scaled symbol streams. The weight vector comprises a plurality of weights, each corresponding to a phase of the power line network. Each of the scaled symbol streams are transmitted on a corresponding phase of the power line network. A zero crossing detector identifies phase information for a receiver. A concentrator adapts signals to be sent to the receiver based upon the phase associated with the receiver.

Abstract: A method for remote crosstalk cancellation, includes: filtering, at a first transmitting end which is connected to a first receiving end over a first line, crosstalk source signals according to values of filtering parameters; synthesizing, at the first transmitting end, a first signal to be transmitted over the first line and the filtered crosstalk source signals; transmitting the synthesized signal from the first transmitting end to the first receiving end over the first line; receiving, at the first transmitting end, a noise statistic related value fed back from the first receiving end; and adjusting, at the transmitting end, the values of the filtering parameters according to the noise statistic related value. A corresponding device and a signal processing system for remote crosstalk cancellation are provided.

Abstract: Embodiments of a method and apparatus of reducing transmit signal components of a receive signal of a transceiver are disclosed. One embodiment of an apparatus includes a transceiver that simultaneously transmits a transmit signal and receives a receive signal. The transceiver includes a transmit DAC that generates the transmit signal based on a transmit digital signal stream. The transmit DAC includes a plurality of transmit DAC circuit elements, and a plurality of transmit DAC switches that control which of the plurality of transmit DAC circuit elements contribute to generating the transmit signal. The transceiver additionally includes an echo cancellation DAC that generates an echo cancellation signal based on the transmit digital signal stream.

Abstract: 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.

Abstract: 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.

Abstract: A method, system and device for use in conjunction with Digital Subscriber Line (DSL) transmission systems, including Far-End Crosstalk (FEXT) cancellation circuitry. According to embodiments of the invention there is provided a system including a central office having a plurality of central modems, and at least one remote modem in communication with the plurality of central modems, the remote modem capable of automatic channel adjustment, and further capable of providing to the central office a channel adjustment parameter, wherein the central office includes a precoder to selectively precode symbols prior to transmission by each of the central modems with an estimation precoding matrix, and a controller to receive from the at least one remote modem respective channel adjustment parameters in response to transmitted symbols precoded with said estimation precoding matrix.

Abstract: A technology for rescuing an object when a failure occurs in a redundant system. In a synchronization memory, an instance of an object, which includes the virtual function discrimination information for discriminating a memory area where a virtual function corresponding to the object is stored, the class information for discriminating a class corresponding to the object, and the object data to be used for the processing of the object, is stored according to the order of the processing. In a function memory, plural kinds of virtual functions generated for each process to be carried out by the object are stored. When the object of a new active server reproduces the process, the class corresponding to this object is discriminated using the class information, and the virtual function discrimination information of this object is rewritten.