Abstract: Combined echo and crosstalk cancellation is provided. Frequency domain adaptive filters are used to remove or reduce the effects of echo and crosstalk for a multi-channel and full-duplex communications system. Data from each transmit channel is buffered and converted to the frequency domain. The frequency domain data is multiplied by crosstalk coefficients to obtain a frequency domain correction signal for each channel. Adaptation of the crosstalk coefficients is based on correlations between the error signals and the data from each of the transmit channels. A single frequency domain transform engine, such as a Fast Fourier Transform engine, is employed for all calculations to save power and area.

Abstract: A circuit can process a sample of a signal to emulate, simulate, or model an effect on the signal. Thus, an emulation circuit can produce a representation of a real-world signal transformation by processing the signal according to one or more signal processing parameters that are characteristic of the real-world signal transformation. The emulation circuit can apply analog signal processing and/or mixed signal processing to the signal. The signal processing can comprise feeding the signal through two signal paths, each having a different delay, and creating a weighted sum of the outputs of the two signal paths. The signal processing can also (or alternatively) comprise routing the signal through a network of delay elements, wherein a bank of switching or routing elements determines the route and thus the resulting delay.

Abstract: A method and system for xDSL crosstalk cancellation is provided. The method includes dividing xDSL signals into a plurality of signal sets; and connecting signals from a same signal set to a same processing unit to be processed. A digital subscriber line access multiplexer (DSLAM) includes a line switching control module and at least one processing unit.

Abstract: A system for performing a single ended line test (SELT) of a selected subscriber line within a bundle of in-service subscriber lines each supporting frequency division multiplexed multi-tone modulated XDSL communications. The system comprises: a crosstalk cancellation module and a SELT module. The crosstalk cancellation module is coupled to the subscriber lines and configured to cancel crosstalk between the selected subscriber line under test and the in-service subscriber lines. The SELT module couples to the crosstalk cancellation module and is configured to coordinate SELT testing with the crosstalk cancellation module to cancel crosstalk between the selected subscriber line and the in-service subscriber lines during testing.

Abstract: A system that incorporates teachings of the present disclosure may include, for example, an echo measurement device having a controller to transmit a test signal in a communication path which is looped back at an end point identified as having an echo problem. The test signal can be transmitted at a remote location from the end point. The test signal can be represented by a limited burst signal of one or more frequencies operating outside a range of an operating frequency of an echo canceller deactivation signal transmitted in the communication path. Additional embodiments are disclosed.

Abstract: Cross-talk is canceled in a cooperative wireless relay network that includes a base station (BS), a relay station (RS), and a mobile station (MS). A coupling channel between a transmit antenna and a receive antenna colocated at the RS is estimated. Cross-talk interference determination is based on a previous transmitted signal by the transmit antenna, and the coupling channel. The cross-talk interference is subtracted from a currently received signal by the receive antenna to obtain a residual signal. The residual signal is then transmitted as a next transmitted signal by the transmit antenna.

Abstract: A Home Phoneline system operating within a Multiple Dwelling Unit includes a Home Phoneline Access Multiplexer (HPAN) that services a plurality of Home Phoneline networks, each including at least one Home Phoneline station. The HPAN synchronizes upstream and downstream transmissions to eliminate Near-Far cross-talk. According to a second operation of the present invention, the HPAN manages the transmission power of the HomePNA stations of the HomePNA networks to reduce Near-Near and Far-Far cross-talk. To optimize throughput across the whole building, station power levels are adjusted based on their location in terms of amounts of attenuation. A third method of operation according to the present invention includes adjusting the receiver sensitivity of the Home Phoneline stations according to detected or characterized levels of cross-talk within the MDU.

Abstract: A multiplexer circuit for CB, AM/FM, and television splits the radio and television signals, adding impedance to the split lines, and providing an amplifier upstream of the split.

Abstract: A system and method of providing multimedia communication services is disclosed. In a particular embodiment, the method includes receiving contextual information including a subscriber identification associated with a wireline communication device at an intelligent service switch (ISS) of an integrated wireline-wireless (IWW) network from a network edge device, where the network edge device has detected a service request at the wireline communication device. The method also includes determining at least one multimedia communication service based on the contextual information and at least one service filter associated with the subscriber identification.

Abstract: A network component comprising at least one processor coupled to a memory and configured to receive a plurality of probing signals from the other end of a plurality of corresponding lines, correlate the received probing signals or their error signals with the orthogonal frequency signatures to determine the dominant crosstalk channels for each of the lines, and send a plurality of signals that correspond to the dominant crosstalk channels to a crosstalk canceller to reduce crosstalk noise in the lines, wherein each of the orthogonal frequency signatures is transmitted in a sync symbol on one of the lines, and wherein the sync symbol comprises a plurality of tones.

Abstract: Systems and methods for determining the configuration of a connection between two devices by measuring an electrical characteristic are provided. Using the measured electrical characteristic, a device is able to select an appropriate communication interface, such as serial, Universal Serial Bus (USB), FireWire, parallel, PS/2, etc., and configure itself appropriately. Systems and methods which determine the physical orientation of a connector with respect to another connector may also be provided alone or in combination with such systems and methods for selecting communication interfaces. The physical orientation of a connector can be determined by measuring an electrical characteristic and a device can then configure itself appropriately. In accordance with the principles of the present invention, device designs can decrease in size and cost as well as simplify operation for the end-user.

Abstract: A method and apparatus for performing stream weighting in a spatial-division multiple access communication system is provided herein. During operation the base station receiver receives channel information from mobiles (also known as users or nodes) and calculates transmit antenna weights that that maximize the power delivered to each mobile while allowing for a small amount of crosstalk to exist between users. Information or data is transmitted to the nodes utilizing the appropriate stream weights. By allowing tolerable amounts of cross talk, the coherent gain to the desired SDMA user can be increased, and thus the overall performance is improved.

Abstract: A method for a network device of a powerline communications network includes selecting between a default preamble signal and a network-specific preamble signal specific to the network but not to a neighboring network and transmitting at least user data in conjunction with the selected preamble signal. Another method for a network device of a powerline communications network includes tuning a sensor to detect network-specific preamble signals specific to the network but not to a neighboring network and receiving at least user data associated with the preamble signals.

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: Embodiments of a multicarrier receiver and method for generating soft bits in a multiple-input multiple-output system are generally described herein. In some embodiments, operational parameters for an equalizer and a soft-bit demapper in a multicarrier receiver are determined. Other embodiments may be described and claimed.

Abstract: Data acquisition from a touch-surface input unit may be disrupted during the generation of radio frequency (“RF”) pulses. To mitigate this problem, touch-surface data acquisition is temporarily halted during RF pulse generation. Data collected prior to temporarily halting is retained, with subsequently acquired data being added to prior collected data.

Abstract: The present invention addresses the problem of a second (or higher) order representation of a transmit signal which is transmitted by a transceiver being mixed into the region of the frequency spectrum of interest to the transceiver receiver, such that it can not then be spectrally filtered out. At its most straightforward, in one embodiment of the invention this is achieved by providing a cross-talk cancellation unit which takes the transmit signal, and obtains the second (or higher) order representation thereof. This representation is then subtracted from the received signal before the signal is passed to the radio control receiver signal processing elements. However, in a more preferred arrangement a filter is also provided, to filter the second or higher order version of the transmit signal, prior to its being subtracted from the received signal. The filter basically takes out the effects of any other filtering or processing which has happened to the transmit signal in the receiver signal chain.

Abstract: Method and device for data processing and communication system with such a device. The method and the device allow data processing via at least one channel. The method includes the following step of transmitting an idle pattern across the at least one channel when no information is conveyed. The idle pattern is created such that interference and/or crosstalk resulting from the idle pattern can be reduced at the receiving side.

Abstract: A method and system are described for canceling an echo signal in analog domain with adaptive filters working in digital domain. In one embodiment, a system includes an analog-to-digital converter (ADC) sampling at two different phases to generate a first error signal and a second error signal having different phases. The ADC operates at a frequency significantly lower than the frequency at which the individual filters run. The first adaptive filter unit and a second adaptive filter unit are independently trained with the first and second error signals, respectively. The first and second adaptive filter units generate echo estimate signals used to cancel the echo signal.

Abstract: A method, apparatus, and system for crosstalk test on multi-subscriber communication lines. The core of the invention is: loading a group of orthogonal spread spectrum codes to the transmitting side of each line, and testing the crosstalk of xSDL lines based on the received signal vector at the receiving side so that the source, amplitude, and phase of the crosstalk can be identified. With the invention, crosstalk test can be implemented in real time on xSDL lines without impacting the transmission performance of other lines. In addition, the test result shows how many lines have a significant impact on the line under test and reflects the severity of the impact, providing a powerful basis for dynamic spectrum management, and optimization of DSLAM system performance.

Abstract: A method and system are described for canceling an echo signal with an echo canceller in the analog domain. In one embodiment, a system includes an echo canceller that includes an interpolation filter unit, operating in a digital domain, that receives a first digital echo estimate signal from a LMS unit and generates a second digital echo estimate signal without oversampling. A digital-to-analog converter (DAC) receives the second digital echo estimate signal and generates an analog echo estimate signal without oversampling. The echo canceller prevents the DAC from adding a high frequency component to the analog echo estimate signal. A subtractor adds the analog echo estimate signal to an incoming signal having an echo signal. The subtractor generates an analog signal with reduced echo signal in the useful frequency band of the incoming signal.

Abstract: A method for enhancing Ethernet channel impairment comprises the steps of sending a sequence to a receiver in a slave transceiver by a master transceiver, and training cancellation filter coefficients of an echo canceller and a near-end cross talk canceller in the master transceiver before the receiver of the slave transceiver converges.

Abstract: A technique to shape the transmit spectrum for a digital subscriber line modem includes utilizing information indicative of crosstalk into the line of another modem. The transmit spectrum is divided by an adjustable transition frequency into a lower frequency region and a mask region. Crosstalk information about the line of the other modem is obtained and the transition frequency and the low frequency region power spectral density are adjusted to account for the data rates of both modems.

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: An adaptive power adjustment method and means based on reducing crosstalk among DSL lines includes: calculating the crosstalk power spectrum density and the crosstalk function from the neighboring line in current line; calculating the transmission power spectrum density of the current terminal device according to the obtained crosstalk power spectrum density and crosstalk function; and the current terminal device controlling the transmission power based on the transmission power spectrum density. According to the adaptive power adjustment method of the present invention, the transmission power can be increased or decreased. The disadvantageous effect due to the crosstalk among xDSL lines is reduced. Present invention can eliminate or reduce adequately the strong impact on remote terminal application scene, and make the lines achieve the optimum operation state.

Abstract: A novel and useful mechanism for the detection, estimation and correction of far-end cross talk (FEXT) caused by transmissions over adjacent wire pairs or cables. The detection, estimation and correction technique of the invention can be used to identify and compensate for FEXT impairments in Ethernet and DSL systems. The detection, estimation and correction is performed utilizing one of several techniques including linear forward filtering, backward decision feedback based filtering and a combination thereof. Results of simulations are presented illustrating the performance improvements provided by the present invention.

Abstract: A communication node for relaying a signal between a source node and a destination node is disclosed. The communication node includes: a relay signal generation unit configured to generate a transmit signal by reducing, from a receive signal, an interference signal from another communication node and performing a process such that the transmit signal is not received as an interference signal by another communication node.

Abstract: Embodiments of a central scheduler and method for adaptive clustering are generally described herein. In some embodiments, a cluster of transmitter-receiver pairs is selected based on minimum singular values calculated from direct channel information and the selected pairs are instructed to perform an interference alignment technique.

Abstract: An electronic circuit capable of reducing crosstalk to such a degree that the crosstalk can be substantially disregarded even where a plurality of communications channels are juxtaposed in close proximity to each other when achieving communications between substrates by inductive coupling. The transmitter coils 11 are placed on a lower chip and the receiver coils 12 are placed on an upper chip, and where it is assumed that the distance between the chips is X, and the distance between the communications channels is Y (that is, the horizontal distance between the coil centers), there exists a position, where the magnetic flux density in the receiver coils 12 resulting from the transmitter coils 11 becomes zero (0), at a predetermined Yo.

Abstract: A method for distributed spectrum management of digital communication systems having a plurality of communication lines on which signals are transmitted and received by respective users, the method comprising the steps of: collecting information about line, signal and interference characteristics of a plurality of the communication lines from a plurality of sources; determining the line, signal and interference characteristics of a plurality of the communication lines; varying power allocation of particular plurality of the communication lines between respective transmitter and receiver taking into consideration the determined line, signal and interference characteristics of a plurality of the communication lines and consideration of a noise weight of a plurality of the communication lines to enable a minimum power on a plurality of the communication lines and to allow required effective data-rates for each of said respective users to be satisfied.

Abstract: A method (200) of cancelling echo in a duplex communication device (100). The method can include detecting a level of noise present on an uplink signal path (104), generating a noise classifier (194) based on the detected level of noise, detecting whether uplink audio is present on the uplink signal path (104) and detecting whether downlink audio is present on a downlink signal path (102). The method further can include generating a double talk flag (136) based at least on the noise classifier, whether uplink audio is present on the uplink signal path, and whether downlink audio is present on the downlink signal path. In addition, the double talk flag, the noise classifier and an uplink signal can be processed to generate an output signal (120) having reduced echo.

Abstract: A circuit can process a sample of a signal to emulate, simulate, or model an effect on the signal. Thus, an emulation circuit can produce a representation of a real-world signal transformation by processing the signal according to one or more signal processing parameters that are characteristic of the real-world signal transformation. The emulation circuit can apply analog signal processing and/or mixed signal processing to the signal. The signal processing can comprise feeding the signal through two signal paths, each having a different delay, and creating a weighted sum of the outputs of the two signal paths. The signal processing can also (or alternatively) comprise routing the signal through a network of delay elements, wherein a bank of switching or routing elements determines the route and thus the resulting delay.

Abstract: Systems and methods for reducing crosstalk are provided. In one implementation, a method is provided. The method includes applying a pilot signal to a disturber twisted pair and measuring near end crosstalk of a victim twisted pair. The coupling characteristics between the disturber and the victim twisted pair are determined. A far end crosstalk function is derived for estimating the far end crosstalk in the victim twisted pair using the determined coupling characteristics. A crosstalk reduction signal is determined using the estimated far end cross talk. The crosstalk reduction signal is injected into the victim twisted pair to reduce crosstalk in the victim twisted pair.

Abstract: 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.

Abstract: A system and method for cross talk compensation in serial link busses, the method comprising: evaluating if a positive potential or a negative potential is being received by a receiver of a victim from an aggressor is dominant; measuring the distance between an incident signal and a decision threshold to obtain a positive or negative value; and using the positive or negative sign as a recovered bit value if positive potential or a negative potential is being received by a receiver of a victim from an aggressor is not dominant and using the sign of the positive potential or a negative potential that is being received by a receiver of a victim from an aggressor if this is dominant.

Abstract: Training, refreshing and/or updating Ethernet link partners for silent channels and/or silent directions of channels may be determined based on control parameters. This may be used to improve energy efficiency in Ethernet communication. Control parameters may comprise a default value and/or may be determined based on prior training, refreshing and/or updating. New values for the control parameters may be generated based on a magnitude of change between current and prior control parameter values or based on performance such as bit error rate. User input may be utilized to determine when to execute the training, refreshing and/or updating. The training, refreshing and/or updating may be done for one or more of a near-end crosstalk canceller, alien near-end crosstalk canceller, far-end crosstalk canceller, alien far-end crosstalk canceller and echo canceller. After the training, refreshing and/or updating, the silent channels may transition to active and/or may remain silent.

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: A communication apparatus with echo cancellation includes a transmitter, a receiver, a digital echo cancellation circuit, a parameter control circuit, and an analog echo cancellation circuit. The digital echo cancellation circuit determines an echo estimation component according to a digital output signal, and performs a digital echo cancellation on a digital input signal according to the echo estimation component. The parameter control circuit generates a control signal according to the echo estimation component. The analog echo cancellation circuit includes a first echo cancellation resistor and a second echo cancellation resistor, wherein the resistances of the first echo cancellation resistor and the second echo cancellation resistor are adjusted according to the control signal.

Abstract: A novel and useful mechanism for the detection and estimation of far-end cross talk (FEXT) caused by transmissions over adjacent wire pairs or cables. The detection and estimation technique of the invention can be used to identify FET impairments in Ethernet and DSL systems. The detection and estimation scheme is performed utilizing an adaptive FEXT canceller filter for detection purposes during normal operation of the system. FEXT filter tap coefficients are determined one at a time using a mechanism shared amongst all taps. Once adapted, the filter coefficients can be used to estimate FEXT strength and to determine spectral measurements of the FEXT impairment noise.

Abstract: Embodiments of the present invention provide a method and a device for crosstalk test in multi-subscriber communication line. The core of embodiments includes: first, transmitting a test signal in a selected line; then, receiving the signal in the line to be tested, and calculating the received signal according to the transmitted test signal; thus, determining whether there is crosstalk between the line to be tested and the selected line according to the calculation result, as well as the value of the crosstalk if the crosstalk exists.

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, 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.

Abstract: Embodiments related to far-end cross-talk coefficient updating in vector transmission systems are depicted and described herein.

Abstract: A method and a device are provided for the echo compensation of a reception signal, a transmission signal being composed of a plurality of transmission subsignals which are generated in a corresponding plurality of signal paths, and a transmission combination signal, which corresponds to a combination of the plurality of transmission subsignals, being delivered to an echo compensation filter in order to generate the echo compensation signal from it. The distribution of the transmission signal may be carried out by distributing of a frequency bandwidth of the transmission signal between a plurality of frequency bands. The method and the device are designed inter alia for the processing of xDSL signals, in particular VDSL2 signals.

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: Embodiments related to noise compensation in data transmission are described and depicted.

Abstract: A victim system detector for detecting whether a second wireless communication system uses frequency bands that are used by a first wireless communication system (detecting whether the second wireless communication system is a victim system) includes a correlator and a decision unit. The correlator calculates a correlation value between a frequency domain baseband signal associated with the first wireless communication system and a correlation sequence of the second wireless communication system. The decision unit determines, based on the correlation value, whether the second wireless communication system is a victim system. Therefore, the victim system is detected accurately and efficiently.

Abstract: A method and apparatus for reducing crosstalk in a multi-channel communication system is disclosed. In one embodiment, outgoing signals in a multi-channel environment are manipulated into a transform domain, such as the frequency domain. Thereafter, the signals may be combined and modified based on a weighting variable to create a cancellation signal. Combined processing greatly reduces system complexity and increases processing speed. After processing in the transform domain, the cancellation signal undergoes further processing to return the cancellation signal into the time domain. The cancellation signal may then be combined with received signals to cancel crosstalk or echo. A method and apparatus for crosstalk cancellation in the analog domain and digital domain is also disclosed.

Abstract: Systems and methods for reducing crosstalk are provided. In one implementation, a method is provided. The method includes applying a pilot signal to a disturber twisted pair and measuring near end crosstalk of a victim twisted pair. The coupling characteristics between the disturber and the victim twisted pair are determined. A far end crosstalk function is derived for estimating the far end crosstalk in the victim twisted pair using the determined coupling characteristics. A crosstalk reduction signal is determined using the estimated far end cross talk. The crosstalk reduction signal is injected into the victim twisted pair to reduce crosstalk in the victim twisted pair.

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. Once a type is identified the crosstalk disturber is compared against all other members of the complete set for that type. Additionally, Multiple Regression (MR) techniques and a Matching Pursuit (MP) algorithm are used to increase the ability of the system and method to identify various crosstalk disturbers.

Abstract: A method of communicating data across a channel that experiences near-end cross talk (NEXT) interference and far-end cross talk (FEXT) interference in alternate intervals. In one embodiment, a first data rate is determined for a first carrier-number mode that is to utilize a first bit table, a second data rate is determined for a second carrier-number mode that is to utilize dual bit tables, a third data rate is determined for a third carrier-number mode that is to utilize a second bit table during a FEXT interval, and a modem is configured to transmit using the mode having a highest data rate.