Abstract: Interference on DSL (Digital Subscriber Lines) systems can be identified by collecting modem data and determining, for a plurality of time intervals, whether the line is carrying traffic and/or whether there are errors on the line. The presence of interference can be inferred from the correlation of the traffic data and the error data.

Abstract: A method includes identifying, at a processor of a crosstalk analyzer, a first communication line of a plurality of communication lines and a second communication line of the plurality of communication lines. The first communication line and the second communication line identified based on a correlation of a crosstalk parameter with respect to the first communication line and the second communication line. The method also includes, responsive to identifying the first communication line and the second communication line, assigning, by the processor, the first communication line to a first port of an access node and the second communication line to a second port of the access node.

Abstract: A video signal and an audio signal are TMDS transmitted from a source device to a sink device. Through a reserved line and a HPD line provided separately from a TMDS transmission line, an Ethernet™ signal is bidirectionally transmitted, and also, a SPDIF signal is transmitted from the sink device to the source device. The Ethernet™ signal bidirectionally transmitted between Ethernet™ transmitter/receiver circuits is differentially transmitted by an amplifier and is received by the amplifier. The SPDIF signal from a SPDIF transmitter circuit is common-mode transmitted from an adder and is received by the adder to be supplied to the SPDIF receiver circuit.

Abstract: Methods and systems for processing signals are provided and may include removing a DC component from a signal envelope comprising a combined signal within a range of allocated FM channels to generate a modified signal envelope. Fluctuation in power in the signal envelope may be detected based on a ratio of a magnitude of the signal envelope and a magnitude of the modified signal envelope. The removing may further include low-pass filtering the signal envelope to generate a low-pass filtered signal envelope. A square values of the low-pass filtered signal envelope may be determined to generate a squared signal envelope. The squared signal envelope may be high-pass filtered to generate a high-pass filtered signal envelope. The fluctuation in power in the signal envelope may be detected based on a ratio of a magnitude of the high-pass filtered signal envelope and a magnitude of the low-pass filtered signal envelope.

Abstract: A method for suppressing interference in a wireless communication comprises receiving a burst of symbols, filtering the burst of symbols using an interference suppression filter with a first plurality of weights, decoding the filtered burst of symbols to generate data corresponding to the burst of symbols, encoding the data to generate a re-encoded burst of symbols, calculating a second plurality of weights for the interference suppression filter based upon the re-encoded burst of symbols, filtering the re-encoded burst of symbols using the interference suppression filter with the second plurality of weights, and decoding the filtered re-encoded burst of symbols.

Abstract: A method and a device process data transmitted via a channel. The channel is at least partially represented by a symmetrical transfer matrix, wherein at least one off-diagonal matrix element of the transfer matrix is determined by its symmetric and/or transposed off-diagonal matrix element and its corresponding diagonal matrix elements of the transfer matrix. In addition, a communication system is provided containing such a device.

Abstract: Systems, methods, apparatus, devices and computer program products enhance uplink inter-cell interference cancellation with HARQ retransmissions. The decoding of a data packet depends on whether the interfering packet was decoded. Since the interfering packet is itself transmitted using a HARQ process, the transmission by the victim UT can be accomplished to take this situation into account. The latency of the victim UT can be varied based on the need for energy efficient transmission. In accordance with one specific aspect, if the receiver can decode multiple packets simultaneously, high data rates can be achieved using packet pipelining.

Abstract: A method and apparatus provide interference mitigation in a heterogeneous network using beamforming. In the method, a macro Mobile Station (MS) receives a broadcast message including a Precoding Matrix Index (PMI) set restricted in a macro cell, measures a Signal-to-Interference plus Noise Ratio (SINR) and a channel power from an adjacent femto Base Station (BS) and calculates a PMI, determines whether to request a dedicated frequency resource for a macro MS on the basis of the measured SINR, the channel power from the adjacent femto BS, and the calculated PMI, and requests the dedicated frequency resource for the macro MS from a macro BS.

Abstract: Aspects of a method and system for interference cancellation substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims. In this regard, a receiver may be operable to receive a differential signal via a differential channel, and to sense a common mode signal on the differential channel. A frequency range in which interference is present in the common mode signal may be determined. The differential signal and the common mode signal may be filtered to attenuate frequencies outside the determined frequency range. A phase and/or amplitude of the filtered common mode signal may be adjusted based on the filtered differential signal and the adjusted and filtered common mode signal may be subtracted from the received differential signal. The common mode signal may be sensed via a pair of resistors coupled to the differential channel.

Abstract: An adaptive interference cancellation system is described. In one example the system operates by receiving a data signal using a DSL (Digital Subscriber Line) and receiving a reference signal, the reference signal corresponding, in part, to noise on the data signal. The reference signal is classified and a noise cancellation signal is applied to the data signal based on the classification.

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: 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: The active microfilter is essentially composed of an active part, which comprises a sign inverter circuit composed of an operational amplifier (13), two resistances and the impedance to be adapted (12), and a passive part which comprises capacitors, coils and resistances. The active microfilter is arranged in an auto-installable device which comprises a circuit for supplying the active part; wherein the aim is to eliminate the reflections caused by line sections, without adaptation, which interfere with the correct operation of the network when accessing broadband with the VDSL2 standard.

Abstract: In a communication system, a precoder is coupled between first and second portions of each of a plurality of transmitters. The precoder is configured to receive an adaptive index representation of a scaled signal associated with the first portion of a first one of the transmitters, and to process the adaptive index representation using an adjusted precoder coefficient to generate a precompensation signal. The precompensation signal is supplied from the precoder to the second portion of a second one of the transmitters for use in precompensation of at least one signal to be transmitted by the second transmitter.

Abstract: In a communication system, a postcoder is coupled between first and second portions of each of a plurality of receivers. The postcoder is configured to receive an adaptive index representation of a scaled signal associated with the first portion of a first one of the receivers, and to process the adaptive index representation using an adjusted postcoder coefficient to generate a postcompensation signal. The postcompensation signal is supplied by the postcoder to the second portion of a second one of the receivers for use in postcompensation of at least one signal received by the second receiver.

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 Orthogonal Frequency Division Multiplex (OFDM) communication system comprises OFDM transmitters, an OFDM receiver, and a subcarrier status data controller for transmitting subcarrier status data to the OFDM receiver. The subcarrier status data indicates the active subcarriers of the OFDM transmitters. The OFDM receiver comprises a receiver, a subcarrier status processor, a channel estimator, and an interference mitigation processor.

Abstract: A method and a device for processing a channel are disclosed. The channel is represented by a MIMO (multiple-input-multiple-output) system having first coefficients associated with transmission lines and second coefficients in particular associated with crosstalk. The method includes (i) clustering of the coefficients of the second coefficients; and (ii) processing of the clustered coefficients.

Abstract: A telecommunication filter arrangement comprising two similar filter cells (T1, S1a, S1b, R1a, R1b; T2, S2a, S2b, R2a, R2b) coupled in cascade to provide a POTS/ADSL splitter. The filter arrangement further comprises at third filter cell (C3, R3, S3) coupled in-between the two other filter cells and comprising a cell capacitor (C3) series coupled with the parallel connection of a cell coil (S3) and a cell resistor (R3). A 3rd order filter is so provided and the filter arrangement behaves as known 5th order filter but with a fixed “switchable insertion loss circuit”. This filter arrangement is thereby cheap, simple and has a small size with respect to the known filter arrangements, while providing good performances.

Abstract: The present invention relates to a vectoring chip unit in a DSL system connectable to a plurality of DSL ports of a DSL chip comprising means for receiving data from each of the plurality of DSL ports, means for performing pre-coding/cancellation in order to reduce crosstalk and means for transmitting a result of the precoding/cancellation to the respective DSL port. Preferably, a system is provided comprising a plurality of said vectoring chips, whereby each vectoring chip is adapted to handle pre-coding/cancellation of a predetermined frequency range and the frequency ranges of each vectoring chip are non-overlapping.

Abstract: Systems and methods for monitoring impulse noise are described. At least one embodiment is a method, which comprises detecting whether impulse noise is present and in response to detecting the presence of impulse noise, performing time domain analysis to determine whether one or more impulse noise sources are present based on minimum interarrival time and maximum impulse length. The method further includes performing frequency domain analysis to estimate frequencies associated with the one or more impulse noise sources and based on the time domain analysis and frequency domain analysis, providing a total number of impulse noise sources and frequencies associated with the impulse noise sources. In this regard, the embodiments described herein provide dual-speed monitoring of impulse noise in the form of short-term and long-term monitoring.

Abstract: Embodiments disclosed herein describe a network device including a class AB common mode suppression (CMS) circuit coupled in parallel between a line voltage source and a physical layer (PHY) device that provides active EMI suppression and Phy device termination. A network connector is coupled to provide the line voltage source to the class AB CMS circuit. The class AB CMS circuit provides current to the PHY device, terminates open-drain transmit drivers of the PHY device and suppresses common mode noise thereby minimizing electromagnetic interference. In other embodiments, the class AB CMS circuit is coupled in parallel between the network connector and a physical layer (PHY) device. The class AB CMS circuit suppresses common mode noise, and terminates open-drain transmit drivers of the PHY device, thereby minimizing electromagnetic interference.

Abstract: The present disclosure discloses a method for common transmission over multiple line pairs, and a transmitting device and a receiving device therefor. The method for common transmission over multiple line pairs includes: modulating information to be sent; and sending a modulated signal to a receiving device over the multiple line pairs; wherein, a transmission spectrum of each transmitter in the multiple line pairs comprises two parts: a first part is a frequency segment that meets a bearer condition of a modulation method, and a second part is a frequency segment that does not meet the bearer condition of the modulation method.

Abstract: A device has a plurality of output terminals to provide a plurality of signals to a plurality of transmission links; at least one input terminal to receive information representing a projection of a complex valued error signal onto one direction; and a determination circuit, coupled to the at least one input terminal.

Abstract: A method is provided for reducing crosstalk problems in digital subscriber loop systems. The problems are associated with a second receiver on a second loop responding to a signal from a first transmitter on a first loop. The signal is actually destined for a first receiver and is coupled between the first transmitter and the second receiver as a crosstalk signal. The method includes the step of transmitting a masking signal from a second transmitter to the second receiver for masking said crosstalk signal.

Abstract: A method for line management includes: acquiring running parameters of a subscriber line; computing a transmitting power spectral density, PSD, and reference virtual noise of the subscriber line according to the running parameters; activating the subscriber line according to the transmitting PSD and the reference virtual noise. A device and system for line management are provided correspondingly. Reference virtual noise needed by virtual noise technology is set rationally according to the information provided by dynamic spectrum management, DSM, Level 2 algorithm. The utilization of the virtual noise technology improves the line stability under the DSM Lever 2 algorithm, and has an effect of optimizing the subscriber line.

Abstract: A communication system adaptively cancels noise and/or interference from signals communicated through a communication channel, such as signals communicated by a telecommunication network. The system, based on a common mode signal of a received signal, generates an estimate of noise or interference within a differential mode signal of the received signal. The system then subtracts the estimate from the differential mode signal in an effort to remove noise from the differential mode signal thereby providing a differential mode signal that is substantially free of the estimated noise or interference.

Abstract: A method for determining at least one operational transmit power Snk over a communication channel (Ln) coupled to a disturbance causing transceiver (n) for at least one tone (k), comprises the steps of provision of at least one reference victim communication channel (Lref) for representing at least one reference victim for all victim communication channels which are degraded by cross-talk interferences by said communication channel (Ln), and maximizing the data rate (Rref) over said at least one reference victim communication channel (Lref) under the constraint that the data rate over said communication channel (Ln) achieves a target rate (Rntarget) without exceeding a power constraint (Pnmax).

Abstract: The present invention describes a system and method for general parameter estimation using adaptive processing that provides a performance that significantly exceeds existing reduced-rank schemes using reduced computational resources with greater flexibility. The adaptive processing is accomplished by calculating a reduced-rank approximation of an observation data vector using an adaptive decimation and interpolation scheme. The new scheme employs a time-varying interpolator finite impulse response (FIR) filter at the front-end followed by a decimation structure that processes the data according to the decimation pattern that minimizes the squared norm of the error signal and by a reduced-rank FIR filter. According to the present invention, the number of elements for estimation is substantially reduced, resulting in considerable computational savings and very fast convergence performance for tracking dynamic signals.

Abstract: In order in particular to allow a synchronization on data packets, the method comprises: a first check that a data set which would be protected by an error detection code, does not comprise any error, the frame comprising the data set; a synchronization on one of the packets comprising the set if the check indicates that the data set does not comprise any error. The invention also relates to a corresponding synchronization module and an apparatus implementing this module.

Abstract: A signal processing system includes an AGC and pre-echo cancellation system for receiving an analog signal, amplifying signal magnitude (over all frequencies) to a pre-determined level by AGC, and removing the immediate transmit pulse from this received signal by pre-echo canceller to provide a second analog signal. The signal processing system also includes a summer for receiving the analog signal; a feed forward equalization (FFE) unit for receiving a signal from the summer; and a slicer for receiving a signal from the FFE unit and providing an output signal. The signal processing system also includes an Echo and NEXT or FEXT cancellation system for receiving the output signal and for providing a signal to the summer for canceling the echo and crosstalk in the signal processing system. The Echo and crosstalk components associated with a signal processing system can be subtracted prior to the FFE.

Abstract: A signal transmission circuit has first to fourth inductors, and first and second varistors. The first and second inductors are magnetically coupled to each other. The first varistor is connected to ground and located posterior to the first inductor and is electrically connected to the first inductor. The third inductor is located between the first inductor and the first varistor and is electrically connected to the first inductor. The second varistor is connected to ground and located posterior to the second inductor and is electrically connected to the second inductor. The fourth inductor is located between the second inductor and the second varistor and is electrically connected to the second inductor.

Abstract: A multi-carrier information transceiver that exhibits robustness against radio frequency interference (RFI) signals present in the communications channel. The transceiver includes a RFI mitigation technique that operates not only during the steady state operation of the transceiver but also during the training stage of the transceiver. That requires dynamically modifying the training signals when the presence of RFI is detected. The modification of the training signals facilitates the estimation of RFI, improving the performance of the multi-carrier transceiver.

Abstract: An interference cancellation method for use in a communications system in which a plurality of communication paths are arranged to transmit and receive respective analogue signals comprises effecting an initialization phase to calculate, for each path, the interference effects of the signals transmitted on that path on the signals received on each of the other paths, and storing for each a plurality of weighting factors representing the interference on each of the other paths respectively. During transmission, said weighting factors are used to generate from the transmitted signal on one of the said paths and to apply said cancellation signals to signals received on said other paths, thereby to cancel the interference effect of said transmitted signals.

Abstract: The specification describes a new technique for reducing interference in EDSL signals caused by local BPL transmission lines. It involves sampling the power line signal to derive a noise signal representing the BPL noise causing the EDSL interference, and mixing the BPL noise signal with the EDSL signal to cancel the BPL noise in the EDSL signal. The technique may be implemented by plugging into a conventional home electrical receptacle, and inserting a small noise canceling module in the EDSL line. Since the method involves an attachment only to the EDSL service, it avoids any involvement with BPL service users and providers.

Abstract: The present invention relates to a device and method for injecting a noise signal into a wire pair of a communication link. In operation a first current source and a second current source are disposed in series with a node therebetween coupled resistively to a wire of the wire pair. A current flow path is provided for balancing the current from the two current sources. A similar circuit is also coupled to the other wire of the wire pair.

Abstract: Device and method for measuring a talking quality of a communication link in a communications network (10). The device comprises measurement means (22; 31, 36) connected to the communication link, which are arranged to subject a degraded speech signal s?(t) with respect to a reference speech signal s(t) to an objective measurement technique for measuring a perceptual quality of means are arranged for producing a quality signal (q) which represents an estimated value concerning the talking quality degradation. The degraded speech signal comprises a returned signal r(t). The measurement means (22; 31, 36) are arranged to execute the objective effects in consequence of noise present in the returned signal. The objective measurement technique comprises the determination of a threshold noise level by determining a local minimum value of the degraded speech signal s?(t).

Abstract: A noise cancellation system configured to isolate and process a common mode noise signal to generate a cancellation signal. The cancellation signal is combined with a differential signal to cancel unwanted differential mode noise that coupled onto the differential signal. In one embodiment a multi-channel communication system utilizes two or more channels that are in close proximity to other alien channels. A common mode signal isolation unit is configured to isolate common mode noise. The common mode noise signal is processed with a filter or other means to generate a cancellation signal. The cancellation signal is combined with the differential signal to thereby cancel noise that coupled onto the differential signal. The processed common mode noise signal may be made to approximate the differential mode noise signal. The common mode signal may be obtained from a center tap of a transformer, or a sensing winding of a three winding transformer.

Abstract: A technique for generating a demodulation ordering used in receive signal processing operations in a BLAST MIMO receiver that is based on a relative comparison of near-to-far resistance measures among vectors forming the estimated channel transfer function matrix is disclosed. This near-to-far resistance comparison provides a resulting demodulation ordering believed equivalent to that provided by conventional V-BLAST techniques without requiring computation of the pseudoinverse of the estimated channel matrix. Also disclosed is a successive interference cancellation technique which employs Multi-Staged Nested Weiner Filtering (MSNWF) to recover soft estimates of the transmitted component-symbols from the vector observed at the BLAST MIMO receiver.

Abstract: In order to reduce noise in telecommunications made over unshielded twisted pair (UTP) of metallic conductors an active electronic circuit for a two-to-four wire hybrid circuit reduces common mode signals without recourse to inductive components. The hybrid has a balance network that dynamically alters its impedance to closely balance with the two wire line impedance. Residual common mode signals are cancelled. Resistors are connected to the wires and the circuit generates a high impedance to differential mode signals and a virtual ground to common mode signals.

Abstract: A method and apparatus for eliminating near-end crosstalk in a communication network are disclosed. Crosstalk generated by communication occurring on a second line is detected on a first line and the phase of the crosstalk detected on the first line is determined. A first signal is communicated on the first line in response to the phase.

Abstract: A subscriber line interface circuit (1?) for supplying line current (IL?) to a two-wire transmission line connected to a load (RL?), comprises a single current amplifier (3?). That single current amplifier (3?) is to be connected with its output terminal to one (B?) of the wires (A?, B?) of the transmission line, while the other wire (A?) of the transmission line is to be connected to a voltage source (V1?) that can be provided within the subscriber line interface circuit (1?) or external thereto.

Abstract: An automatic system for the provisioning, deployment and management of digital subscriber lines (DSL) in a telephone network uses data on loop composition, electromagnetic interference and crosstalk between lines to optimize the performance and correct problems with one or more symmetric and or asymmetric digital subscriber lines in a cable. The system optimizes DSL lines on an individual basis using measurements and data. The optimal transmit power spectral density (PSD) for each DSL can be found in an iterative manner. Starting each DSL with some predetermined starting parameter, the transmit PSD of each DSL is optimized in round-robin fashion. The crosstalk into a given DSL is calculated as the power sum of all transmissions passed through their measured crosstalk couplings. An asymmetric DSL has its transmit PSD optimized by using the “waterfilling” technique.

Abstract: A method and an apparatus for optical transmission line power feed interference compensation for compensating for an electrical interference signal in a power feed conductor (12; 52) and in an associated second conductor (14; 54). The interference signal may be produced by electromagnetic induction or by local variation in earth potential. The compensation is performed by producing a variable compensation signal from an electrical interference signal produced in the second conductor and inputting the variable compensation signal onto the power feed conductor, in order substantially to compensate for or cancel the electrical interference signal produced in the power feed conductor.

Abstract: An improved system and method for communicating information on a transmission medium is disclosed. The disclosed system and method provide improved communications on the transmission medium in the presence of interference, which may take the form of uncorrelated interference from different services on neighboring transmission mediums. In one embodiment, the communications system includes a subscriber modem, a central office modem; and a communications channel coupled between the subscriber modem and the central office modem. The communications channel transports uplink signals from the subscriber modem to the central office modem, and downlink signals from the central office modem to the subscriber modem.

Abstract: An ADSL front end is implemented with an adaptive AM interference canceller to cancel out either a carrier signal of an interfering AM radio signal, or a carrier signal and its sidebands of an interfering AM radio signal, from a received ADSL signal. By canceling an interfering AM radio signal rather than simply filtering out the relevant interfered with frequency band, the interfered with frequency band remains useable for ADSL transmission. In one embodiment, a reference AM radio receiver is either fixedly or adaptively tuned to the carrier frequency of an interfering AM radio station, and the received signal in the frequency band surrounding that carrier frequency is digitized and provided to an adaptive interference canceller. The adaptive interference canceller adaptively adjusts a time delay and phase of the generated AM interference signal to optimize cancellation at a hybrid of the same AM radio signal received as interference over a subscriber line.

Abstract: A method of optimally distributing signal power for multiple users over a xDSL or wireless channel considers uses computationally efficient tools to achieve improved crosstalk avoidance. The method chooses between EQPSD and FDS signaling in a fashion that maximizes overall data rate. Rather than choosing EQPSD signaling in regions where there is low self-NEXT, but where the echo is high (relative to signal power), the method selects FDS signaling since the communication system acts in a manner similar to self-NEXT in such regions.

Abstract: Crosstalk between subscriber loops used to transmit different broadband services through the same bundled telephone cable is a significant limitation to providing digital subscriber line services. A method for estimating the crosstalk, identifying the sources of the crosstalk and predicting additional sources of crosstalk are disclosed. The crosstalk sources are identified in the frequency domain by maximizing the correlation with a “basis set” of received crosstalk PSDs which consist of the cascade of a finite set of known transmit PSDs types times a representative set of crosstalk couplings. Multiple crosstalk types are identified with a technique of successive spectral subtraction. This information can be used to perform crosstalk cancellation and spectrum management for DSL systems.

Abstract: A receiver for high-speed data communications, which receives a differential signal through a pair of signal lines. The receiver includes a common-mode choke, which has first and second signal windings, which are respectively coupled in series to the pair of signal lines so as to attenuate common-mode interference in the differential signal. The choke also has a sampling winding, which is inductively coupled to the signal windings so as to generate a sampled signal responsive to current flowing in the signal windings. Signal processing circuitry is coupled to receive the sampled signal from the sampling winding and to receive the differential signal from the signal windings and to process the differential signal responsive to the sampled signal.