Entries |
Document | Title | Date |
20080219431 | METHOD AND APPARATUS FOR ECHO CANCELLATION - A telephony system equipped with an echo cancellation module is disclosed. A hybrid interface circuit outputs an outbound signal to a wall jack while receiving an inbound signal from the wall jack. The inbound signal may contain a line echo of the outbound signal caused by the impedance mismatches in the hybrid interface circuit. A line echo canceller containing an adaptive filter is used to cancel the line echo in the inbound signal based on the learned line echo path characteristics captured in the training period. During a brief period after the telephony system is activated, the line echo canceller enters into a calibration mode wherein its adaptive filter is trained to learn the line echo path characteristics. During the calibration mode, the line echo canceller generates a calibration signal as the outbound signal and receives the line echo from the hybrid interface circuit to perform learning of the line echo path characteristics. | 09-11-2008 |
20080232577 | Echo cancellation - A method of determining if an echo canceller comprised in a communication channel that is used to transmit at least one tonal signal and characterized by a model echo path of the channel, is acceptably adapted to cancel echoes in the channel, the method comprising: determining a performance measure how well the canceller cancels echoes of at least one test signal characterized by at least one frequency different from a frequency of the at least one tonal signal; and determining if the canceller is acceptably adapted responsive to the measure. | 09-25-2008 |
20080253552 | Acoustic Echo Canceller - An acoustic echo cancellation device ( | 10-16-2008 |
20080292093 | METHOD AND APPARATUS FOR ECHO CANCELLATION - A technique of echo cancellation in a communication system. A method and/or apparatus of echo cancellation that may be suitable for performing echo cancellation under single talk and double talk conditions. A method and/or apparatus of echo cancellation that may significantly reduce a residual echo in a single talk environment (e.g. present in many telecommunications systems) without distorting a near end signal in a double talk environment. A method and/or apparatus of echo cancellation that may reduce a residual echo in single talk and double talk environments by applying a post-processing technique to an ECLMS algorithm. | 11-27-2008 |
20090003586 | SIGNAL PROCESSOR AND METHOD FOR CANCELING ECHO IN A COMMUNICATION DEVICE - The invention provides a signal processor installed in a communication device. In one embodiment, the signal processor comprises a voice activity detector, a nonlinear echo processor, and a speaker attenuation module. The voice activity detector generates a control signal indicating whether both a far-end talker at a far end and a near-end talker at a near end are speaking or only the far-end talker is speaking. The nonlinear echo processor, controlled by the control signal, cancels more nonlinear echo from the near-end signal in time domain while only the far-end talker is speaking and cancels less nonlinear echo from the near-end signal in time domain while both the far-end talker and the near-end talker are speaking. The speaker attenuation module, controlled by the control signal, attenuates the far-end signal while both the far-end talker and the near-end talker are speaking. | 01-01-2009 |
20090034712 | Echo cancellation in which sound source signals are spatially distributed to all speaker devices - A system includes microphone devices, echo cancellation mechanism, and speaker devices. Each echo cancellation mechanism corresponds to one of the microphone devices. Each speaker device corresponds to a sound source signal. Each sound source signal is spatially distributed to all the speaker devices, and each echo cancellation mechanism receives as a reference signal a combination of all the sound source signals. | 02-05-2009 |
20090046847 | ACOUSTIC ECHO CANCELLER USING MULTI-BAND NONLINEAR PROCESSING - An echo canceller ( | 02-19-2009 |
20090067615 | ECHO CANCELLATION USING GAIN CONTROL - A device for reducing echo by controlling microphone and/speaker gain in a telecommunications system is disclosed. An exemplary embodiment of the device may have an echo detector, echo level detector, and a gain controller. The echo detector detects an echo in a transmitted audio communication signal. The echo level detector determines the volume level of the detected echo. The gain control may adjust the gain of a microphone transmitting and/or speaker broadcasting the audio communication signal based on the echo level detected. The gain control and echo cancellation may cooperate with each other. | 03-12-2009 |
20090074177 | Echo canceler and echo canceling program - An echo canceler uses an adaptive filter to remove an echo of an incoming far-end signal from an outgoing near-end signal. Filter coefficients are calculated and updated while the far-end signal is active so as to minimize the residual echo. In addition, the far-end signal and near-end signal are sampled to generate simulated far-end and near-end signals, from which substitute filter coefficients are similarly calculated while the far-end signal is silent. When the far-end signal changes from silent to active, the substitute filter coefficients are swapped in as initial values for the filter coefficients, thereby speeding up subsequent convergence of the filter coefficients without significant added computational cost. | 03-19-2009 |
20090110185 | VEHICLE CALL DEVICE, CALL SYSTEM, CENTER, AND CALLING METHOD - A vehicle call device, a call system, a center, and a calling method capable of detecting a problem while controlling the cost increase are disclosed. The vehicle call device includes a speaker mounted in a vehicle, the speaker outputting a received voice of an opposite communication party; a microphone mounted in the vehicle; an echo canceller unit removing the received voice that has been output from the speaker and input into the microphone; a detecting unit detecting an emergency situation of the vehicle; and a remove preventing unit preventing the eco canceller unit from removing the received voice when the detecting unit detects the emergency situation. | 04-30-2009 |
20090122975 | METHOD, SYSTEM AND APPARATUS FOR CONTROLLING AN ECHO CANCELLER DURING FAXING - A method, an apparatus and a system for controlling an echo canceller in faxing are provided. The method includes: after detecting a triggering signal, the signal detecting apparatus enables the echo canceller to be in the initial state if the echo canceller is in the disabled state. In the apparatus and the system provided by embodiments of the present invention, a signal detecting apparatus is configured to detect the signals in the fax system. After a triggering signal is sent in the system, the disabled echo canceller is enabled to be in the initial state. In this way, the disabled echo canceller can be restarted during faxing. In the prior art, the disabled echo canceller is hard to be restarted during faxing. Hence, the technical solution provided by embodiments of the present invention may guarantee the fax reliability and the quality of the faxed images. | 05-14-2009 |
20090185674 | Communication system - In an embodiment, a method for removing an echo component is a first signal received at an audio input device includes outputting a second signal from an audio output device, receiving at the audio input device the first signal wherein the echo component in the first signal is the result of the second signal traversing an echo path; detecting if the first signal only comprises the echo component; determining an estimate indicative of the echo path by comparing the first signal and the second signal when it is detected that the first signal only comprises echo; applying the estimate indicative of the echo path to the first signal to determine an equalised first signal; comparing the equalised first signal with the second signal to determine an estimate indicative of the echo component; and removing the echo component from the first signal in dependence on the estimate indicative of the echo component; wherein the step of detecting if the first signal only comprises the echo component comprises comparing a characteristic of the equalised first signal to a characteristic of the second signal. | 07-23-2009 |
20090279686 | ECHO PATH CHANGE DETECTION IN TELECOMMUNICATIONS NETWORKS - In one embodiment, the present invention is a method for detecting an echo path change (EPC) in a telecommunications network. The method detects whether the effectiveness of echo cancellation of an echo canceller has decreased relatively significantly. Once a relatively significant decrease is detected, the method determines whether the decrease was an EPC or an inadvertent detection of double talk (DT). In particular, the method considers whether echo is effectively cancelled over a hangover period. Further, echo return loss (ERL) estimates are generated over the hangover period and compared to a lowest-possible ERL for the network. If both (1) echo cancellation is ineffective and (2) a sufficient number of ERL estimates are not below the worst-case ERL, then an EPC decision is made. If either (1) echo cancellation is effective or (2) a sufficient number of ERL estimates are below the worst-case ERL, then a DT decision is made. | 11-12-2009 |
20090316881 | TIMESTAMP QUALITY ASSESSMENT FOR ASSURING ACOUSTIC ECHO CANCELLER OPERABILITY - A voice communication end device provides echo reduction when operating in a full duplex mode using acoustic echo cancellation, which includes periodic audio queue adjustments to account for drift. The end device performs a quality assessment by calculating consistency statistics for the queue adjustments to determine whether acoustic echo cancellation would be ineffective, and if so falls back to a half duplex mode using voice switching. | 12-24-2009 |
20100034372 | METHOD AND SYSTEM FOR DISTRIBUTED SPEAKERPHONE ECHO CANCELLATION - A speakerphone system includes first and second speakerphones connected via a network and a first processor in the first speakerphone and a second processor in the second speakerphone, each of the speakerphones having a first, active, mode for participating in a call with a telephone and a second, idle, mode, wherein, when the first speakerphone is operating in the first mode and the second speakerphone is operating in the second mode, the first speakerphone is adapted to send voice data packets to the second speakerphone, the second speakerphone is adapted to receive voice data packets from the first speakerphone, perform echo cancellation processing on the voice data packets and send the processed voice data packets back to the first speakerphone, and the first speakerphone is adapted to receive the processed voice data packets from the second speakerphone and use the processed voice data packets in the call. | 02-11-2010 |
20100046738 | Method and apparatus for DMT crosstalk cancellation - 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. | 02-25-2010 |
20100195815 | ECHO REMOVING APPARATUS - An echo removing apparatus that can remove an echo appropriately if the produced sound volume becomes large although the configuration is simple is provided. A control section | 08-05-2010 |
20100226491 | NOISE CANCELLATION FOR PHONE CONVERSATION - The present disclosure relates to systems and methods for noise cancellation of phone conversation. Some of the systems can include a phone having a microphone and a noise cancellation device. In some examples, the noise cancellation device has a microphone for receiving an input sound wave and positioned proximate the phone microphone, a processor for generating a noise cancellation sound wave based on the input sound wave, and a speaker for outputting the noise cancellation sound wave. The phone microphone and the noise cancellation device microphone can be shared or different microphones, and can also be microphone is integral to the phone. The shared or separate microphones can be part of a phone headset. | 09-09-2010 |
20110069829 | METHODS, APPARATUS AND ARTICLES OF MANUFACTURE TO CANCEL ECHO FOR COMMUNICATION PATHS HAVING LONG BULK DELAYS - Example methods, apparatus and articles of manufacture to cancel echo for communication paths having long bulk delays are disclosed. A disclosed example method includes determining a first location of a first largest magnitude of a first plurality of coefficients of an echo canceller, the first plurality of coefficients separated by two or more sample intervals, and cancelling an echo contained in a received signal using a second plurality of coefficients of the echo canceller and a first offset selected based on the first location, the second plurality of coefficients separated by one sample interval. | 03-24-2011 |
20110075833 | Echo Canceller With Correlation Using Pre-Whitened Data Values Received By Downlink Codec - Duplex audio communications over a network use compressed audio data, with linear prediction coefficients (LPCs) and variances by which sample values differ from predictions. A adaptive echo canceller for a transceiver develops finite impulse response filter (FIR) coefficients characterizing an echo path between its local audio output and audio input. The received/decompressed audio data is applied to the FIR coefficients, and the predicted echo is subtracted from the uplink signal. Echo is detected as cross-correlation of the receive signal versus the uplink/send signal over time. In one embodiment, the cross-correlation is determined using a pre-whitened receive signal, obtained by adopting the variance values received over the network by the downlink Codec. Apart from the uplink Codec, no speech analysis filter or process is needed. The technique is apt for GSM, AMR and similar compressed audio communications. | 03-31-2011 |
20110170683 | Systems and Methods for Echo Cancellation and Echo Suppression - Traditionally, echo cancellation has employed linear adaptive filters to cancel echoes in a two way communication system. The rate of adaptation is often dynamic and varies over time. Disclosed are novel rates of adaptation that perform well in the presence of background noise, during double talk and with echo path changes. Additionally, the echo or residual echo can further be suppressed with non-linear processing performed using joint frequency-time domain processing. | 07-14-2011 |
20110194685 | METHOD AND SYSTEM FOR NONLINEAR ACOUSTIC ECHO CANCELLATION IN HANDS-FREE TELECOMMUNICATION DEVICES - A method and system for determining and compensating for a non-linearity in a hands-free acoustic telecommunication device is disclosed. The method determines a back electromotive force signal induced in a loudspeaker from at least one of a coil voltage, a current signal and estimates of coil resistance and inductance, estimating at least one of a cone position and a cone velocity from the BEMF integrated with respect to time and determining an estimate of an echo value from a series connection of an estimated inverse of a force factor function primitive and the estimated acoustic impulse response; and outputting the estimated echo value. | 08-11-2011 |
20110243318 | APPARATUS AND METHOD FOR CANCELING ECHO - According to one embodiment, in response to a first acoustic signal output, a second acoustic signal is input. A filter unit is configured to generate a third acoustic signal by convoluting the first acoustic signal with coefficients. A subtraction unit is configured to generate a fourth acoustic signal by subtracting the third acoustic signal from the second acoustic signal. An estimation unit is configured to decide whether a sound volume of the first acoustic signal is below a predetermined threshold, and to set a sound volume of the second acoustic signal as a non-echo sound level when the sound volume of the first acoustic signal is below the predetermined threshold. A determination unit is configured to determine a step size to correct the coefficients using the non-echo sound level. A correction unit is configured to correct the coefficients using the step size. | 10-06-2011 |
20120063590 | OPERATING POINTS FOR SPECTRUM MANAGEMENT IN DIGITAL SUBSCRIBER LINES - A method of determining a number of operating points for spectrum management of a plurality of digital subscriber lines in a communications network, the method comprising the steps of: determining optimization criteria (O | 03-15-2012 |
20120183133 | DEVICE AND METHOD FOR CONTROLLING DAMPING OF RESIDUAL ECHO - The present invention relates to a device, such as a communication device, comprising an adaptive foreground filter configured to calculate a first echo estimation signal based on a first input signal, and an adaptive background filter being more rapidly adapting than the foreground filter and configured to calculate a second echo estimation signal based on said first input signal. Embodiments of the device further comprise damping control means for controlling damping of an echo-cancelled output signal. The device in various embodiments includes that the damping control means is configured to calculate a maximum echo estimation signal using both the first and the second echo estimation signals, and control the damping of the echo-cancelled output signal based on said maximum echo estimation signal and/or a signal derived from said maximum echo estimation signal. | 07-19-2012 |
20120195423 | SPEECH QUALITY ENHANCEMENT IN TELECOMMUNICATION SYSTEM - Technologies are generally described for an echo cancelling device of a telecommunication system. In some examples, an echo canceling device may include a noise reduction unit configured to reduce a background noise around a near-end talker from a near-end signal provided by a microphone, a double talk detector configured to detect a double talk event based on the noise-reduced near-end signal and a far-end signal, and a filtering unit configured to receive the far-end signal and the near-end signal provided by the microphone. | 08-02-2012 |
20120219146 | ADAPTIVE DELAY COMPENSATION FOR ACOUSTIC ECHO CANCELLATION - An acoustic echo cancellation system buffers remote side signals to one or more storage areas. A delay controller filters and delays the remote side signals to correlate the remote side signals to local side signals. An acoustic echo cancellation core pulls the remote side signals from the buffer through a delay controller. A delay estimator generates an estimate of a delay between the buffered remote side signals and the local side signals. The delay estimator renders a confidence level that indicates a degree of likelihood for each potential match between delayed remote side signals and the local side signals. The acoustic echo cancellation core substantially cancels a portion of the echo or reverberation within the local side signals based on the estimate of the delay and the confidence level. | 08-30-2012 |
20120237017 | METHOD, DEVICE AND SYSTEM FOR EXTENDING CHANNELS - The present invention provides a method, a device and a system for extending channels, and belongs to the field of communications technologies. The method includes: generating a non-cascade extended channel by using a first channel and a second channel; and generating a first-level cascade extended channel by using the non-cascade extended channel and a third channel, where the first channel and the second channel are both twisted-pair channels, and the third channel is a twisted-pair channel or another non-cascade extended channel. The device includes a first transformer and a second transformer. The system includes a first device and a second device. | 09-20-2012 |
20120250852 | ACOUSTIC ECHO CANCELLATION FOR HIGH NOISE AND EXCESSIVE DOUBLE TALK - Methods and devices for improved echo cancellation in high noise environments, such as in-car speakerphones and the like, are provided that improve cancellation convergence in a high noise environment and in the presence of double talk. A new update method enables a robust echo canceller to update with reduced concern for the canceller being in a receive state or a double talk state. If a signal generated by a local talker is substantially the same as high noise, in terms of corruption of the echo canceller, the echo canceller converges in a robust manner even with continuous high noise at the input. | 10-04-2012 |
20130003960 | Full Duplex Speakerphone Design Using Acoustically Compensated Speaker Distortion - A telecommunication system including a fall duplex speakerphone, comprising a first microphone to generate a coupled signal including uplink information and non-linear distortion sensed by the first microphone in a speaker phone mode, a second microphone to generate a reference signal including downlink information and the non-linear distortion sensed by the second microphone in the speaker phone mode, and an acoustic echo canceller (AEC) to receive the coupled signal from the first microphone, to receive the reference signal from the second microphone, and to cancel out the non-linear distortion included in the coupled signal based on the non-linear distortion included in the reference signal. | 01-03-2013 |
20130003961 | FAR-END CROSSTALK CANCELING METHOD AND DEVICE - A method for remote crosstalk cancellation, includes: the combination transmitting signal is performed a pre-coding of crosstalk cancellation in the manner of self-adapting filtering, the self-adapting changes of the values of filtering parameters are guided correctly with the influence of the crosstalk component in the received signals which is reflected indirectly by relevant values of the noise statistic reported by the receiver. A corresponding device for remote crosstalk cancellation is provided. | 01-03-2013 |
20130028409 | APPARATUS AND METHOD FOR ECHO CONTROL IN PARAMETER DOMAIN - The present invention relates to call voice signal processing, and particularly, to apparatus and method for echo control in parameter domain. The apparatus includes: an echo detection module configured to extract parameter domain characteristic parameters of a far-end output signal and a near-end input signal, respectively, through parameter domain decoding, and detect whether a near-end input signal frame is an echo frame according to the parameter domain characteristic parameters; and a transition module configured to re-quantize the fixed codebook gain, the adaptive codebook gain and an LSF prediction error in the near-end input signal frame when the echo detection module detects the near-end input signal frame as a non-echo frame, and replace the original fixed codebook gain, the original adaptive codebook gain and the original LSF in the near-end input signal frame. | 01-31-2013 |
20130077776 | Method, System and Computer Program Product for Acoustic Echo Cancellation - In response to a first signal, a first sound wave is output. A second sound wave is received that includes an acoustic echo of the first sound wave. In response to the second sound wave, a second signal is output that cancels an estimate of the acoustic echo. The estimate of the acoustic echo is iteratively adapted to increase a statistical independence between the first and second signals, irrespective of whether a first voice is present in the first sound wave, and irrespective of whether a second voice is present in the second sound wave. | 03-28-2013 |
20130177150 | CROSSTALK REDUCING CONDUCTOR AND CONTACT CONFIGURATION IN A COMMUNICATION SYSTEM - There is disclosed a method for reducing cross talk between first and second cables in a data transmission system, each of the cables comprised of a pair of conductors. The method comprises the steps of providing a first contact interconnected with a first conductor of the pair of conductors of the first cable, wherein the first contact emits a first signal, providing a pair of contacts, each of the pair of contacts interconnected with a different conductor of the pair of conductors of the second cable, and positioning the first contact relative to the pair of contacts such that an amplitude of the signal received at one of the second pair of contacts is substantially the same as an amplitude of the signal received at another of the second pair of contacts. | 07-11-2013 |
20130243183 | MULTI-RECEIVING TERMINAL ECHO CANCELLATION METHOD AND SYSTEM - A multi-receiving terminal echo cancellation method and a multi-receiving terminal echo cancellation system are disclosed. The present invention performs echo filtering on receiving terminal signals in M channels by means of echo filters to obtain filtered receiving terminal signals in M channels, and subtracts the filtered receiving terminal signals in M channels from a sending terminal signal to obtain a system output signal in which receiving terminal echoes have been cancelled; and at the same time, the present invention buffers the receiving terminal signals in M channels by means of buffers, calculates a decorrelation matrix according to each of the receiving terminal signals in M channels that are buffered within preset length, decomposes the buffered receiving terminal signals in M channels into decorrelated receiving terminal signals in M channels by means of the decorrelation matrix, and calculates update amounts of the echo filters according to the decorrelation matrix, the decorrelated receiving terminal signals in M channels and the system output signal that is fed back. The technical solutions of the present invention can support the situation of two or more receiving terminals, and are suitable for situations in which the correlation between a plurality of receiving terminal signals is variable. | 09-19-2013 |
20130266134 | COMMUNICATION CIRCUIT EMPLOYING OPTOCOUPLER - An communication circuit of a communication device includes an interface unit, a direct current (DC) control circuit, a voice output circuit includes a voice input terminal, and a voice receiving circuit includes a voice output terminal. The interface unit outputs human speech and receives human speech from another communication device. The | 10-10-2013 |
20130287203 | Reduction of Loudspeaker Distortion for Improved Acoustic Echo Cancellation - Methods and apparatuses for improved echo cancellation are disclosed. In one example, an audio signal to be output at a loudspeaker is received and processed to generate an optimized audio signal. The optimized audio signal produces a reduced distortion when output at the loudspeaker. The method further includes utilizing the optimized audio signal to reduce echo in a transmit audio signal. | 10-31-2013 |
20130294597 | Aligning the Upstream DMT Symbols of Multiple Lines in a TDD DSL System - A method comprising transmitting a delay value to each of a plurality of digital subscriber line (DSL) transceivers, by a distribution point unit (DPU), and receiving a plurality of signals at substantially the same time, wherein each of the plurality of signals is from a different DSL transceiver in the plurality of DSL transceivers and transmitted at different times based on the delay value and a corresponding propagation delay. | 11-07-2013 |
20130294598 | TELEPHONE TERMINAL AND HANDLE OF TELEPHONE TERMINAL - Embodiments of the present invention disclose a telephone terminal. The telephone terminal includes: a first handle end, a second handle end, a voice processing unit, and an input-output unit. The voice processing unit receives a first voice signal sent by the first handle end and a second voice signal sent by the second handle end, processes the first voice signal and the second voice signal, and sends the processed voice signal to a communication peer through the input-output unit. According to the embodiments of the present invention, voice signals of the two handle ends are received, processed, and then sent to the communication peer, a problem of failing to send a speech signal of a user to the communication peer when the user holds the handle upside down may be solved, and user experience is improved. | 11-07-2013 |
20130301824 | CROSSTALK CANCELLATION DEVICE AND METHOD WITH IMPROVED VECTORING STABILISATION - A crosstalk cancellation device cancels crosstalk noise of at most M disturbing communication lines in a victim communication line forming part of a vectoring group. The crosstalk cancellation device gradually decreases the cancellation depth of a cancelled disturbing communication line in the victim communication line upon a crosstalk noise variation in the vectoring group requiring cancellation of crosstalk noise of a not yet cancelled disturbing communication line in the victim communication line. | 11-14-2013 |
20130308771 | METHOD AND APPARATUS FOR HIERARCHICAL ADAPTIVE FILTER - A method and apparatus for filtering a reference signal by a series of taps having coefficients, comprising dividing the taps into at least one layer of a plurality of groups, each group comprising a plurality of taps, as a first layer, forming a plurality of coefficients arranged in at least one group, as at least one subsequent layer and forwarding multiply-accumulate results of each group in each layer sequentially to the at least one group in the at least one subsequent layer to generate an output signal, and adjusting the coefficients based on an error signal formed as a difference between the output signal and a received input signal related to the reference signal and an interim error signal as a difference between the input signal and a summation of the multiply-accumulate results of at least one layer. | 11-21-2013 |
20140023188 | COMPUTATION SAVING ECHO CANCELLER FOR A WIDE BAND AUDIO SIGNAL - A canceller splits a signal, transmitted from a near end terminal (ET) to a far ET, into a sub-sampled signal corresponding to a higher frequency sub-band of the signal transmitted to the far ET, and a sub-sampled signal corresponding to a lower frequency sub-band of the signal transmitted to the far ET; and splits a signal received from a far ET into a sub-sampled signal corresponding to a higher frequency sub-band of the signal received from the far ET, and a sub-sampled signal corresponding to a lower frequency sub-band of the signal received from the far ET. The canceller includes a first adaptive filter for filtering the sub-sampled signal corresponding to the lower frequency sub-band, a second adaptive filter for filtering the sub-sampled signal corresponding to the higher frequency sub-band, and controls the adaptation of the first and second adaptive filters so that these two adaptations are never simultaneous. | 01-23-2014 |
20140023189 | Dynamic Target Margin Adaptation for DSL Transmission Lines - A method and arrangement is proposed for adaptively generating a target noise margin for use on a DSL transmission line. The method includes determining a first quantity representing a current noise power on the line using line parameter data relating to the transmission performance of the line, determining a second quantity representing a worst-case noise power on said line using previously obtained values of the line parameter data, calculating the difference between the first and second quantities to generate a difference value, setting a target noise margin as at least equal to said difference value, and providing the target noise margin for use on the line upon initialisation of the line. In a preferred embodiment, the line parameter data is the bit loading on the line and the first and second quantities are values of the average signal-to-noise ratio on the line derived from the bit loading data. | 01-23-2014 |
20140072118 | TRANSCEIVER - A transceiver includes: a TV signal receiving unit for generating a first audio signal from a received broadcast wave; a decoder for decoding a reception signal received from the transceiver, to generate a second audio signal; an adding unit for transmitting the second audio signal to a speaker or adding up and transmit, to the speaker, the first audio signal and the second audio signal, and for outputting a reference signal; and an echo canceller for estimating a pseudo echo component from the reference signal, and cancels the pseudo echo component in a picked-up signal picked up by microphone a sound outputted from the speaker. The adding unit, when the TV signal receiving unit receives the broadcast wave, adds and transmits, to the speaker, the first audio signal and the second audio signal, and outputs a signal resulting from the addition as the reference signal to the echo canceller. | 03-13-2014 |
20140093066 | METHOD FOR DETECTING DOUBLE-TALK CONDITION AND SYSTEM USING THE SAME - A method for detecting a double-talk condition and an echo cancellation system using the same are introduced herein. According to an exemplary embodiment, the method may be adapted to an double-talk detector of an echo cancellation system and includes the following steps: obtaining an input signal with a first power; computing a second power, wherein the second power is a power combination of at least one estimated signal; determining whether the double-talk condition occurs according to a relationship between the first power and the second power, when the first power is larger than the second power, the double-talk condition occurs. | 04-03-2014 |
20140093067 | METHOD, APPARATUS, AND SYSTEM FOR REDUCING LINE-TO-LINE CROSSTALK DURING TRANSMISSION OF DIGITAL SUBSCRIBER LINE SERVICE - A method, an apparatus, and a system for reducing line-to-line crosstalk during transmission of a digital subscriber line service are disclosed, where the method includes: before a service is provisioned, obtaining, by a service provider according to a service transmission rate and a topology scenario parameter that are provided by a service receiving side device, a power spectral density of a line in a process of receiving a service by the service receiving side device; and provisioning, by the service provider, a service for the service receiving side device according to the power spectral density. | 04-03-2014 |
20140098950 | Detection and Suppression of Returned Audio at Near-End - Audio from a near-end that has been acoustically coupled at the far-end and returned to the near-end unit is detected and suppressed at the near-end of a conference. First and second energy outputs for separate bands are determined for the near-end audio being sent from the near-end unit and for the far-end audio being received at the near-end unit. The near-end unit compares the first and second energy outputs to one another for each of the bands over a time delay range and detects the return of the sent near-end audio in the received far-end audio based on the comparison. The comparison can use a cross-correlation to find an estimated time delay used for further analysis of the near and far-end energies. The near-end unit suppresses any detected return by muting or reducing what far-end audio is output at its loudspeaker. | 04-10-2014 |
20140119536 | Spectrum Management - Various methods, techniques and devices are disclosed which optimize an output power spectral density taking properties and changes of crosstalk reduction like crosstalk precompensation into account. The techniques disclosed may for example be employed in distribution points of a communication system. | 05-01-2014 |
20140185792 | BIDIRECTIONAL COMMUNICATION SYSTEM AND METHOD FOR COMPENSATING FOR UNDESIRED FEEDBACK IN THE BIDIRECTIONAL COMMUNICATION SYSTEM - The invention relates to a bidirectional communication System ( | 07-03-2014 |
20140233722 | Reducing the Feedback Overhead During Crosstalk Precoder Initialization - An apparatus comprising a receiver coupled to a digital subscriber line (DSL) between an exchange site and a customer premise equipment (CPE) and configured to send a feedback error message to train a precoder coupled to the exchange site, wherein the feedback error message comprises a plurality of error components and an indication of a quantity of bits per error component, a quantization accuracy per error component, or both. Included is a method comprising sending an error feedback message to a DSL crosstalk precoder to train the crosstalk precoder, wherein the error feedback message comprises an error vector and a quantization scaling factor of the error vector. | 08-21-2014 |
20140233723 | Method And System For Sampling Rate Mismatch Correction Of Transmitting And Receiving Terminals - Disclosed in the invention is a method and system for sampling rate mismatch correction of transmitting and receiving terminals, which can obtain a high-precision sampling rate mismatch in real time, carry out sampling rate correction on transmitting and receiving terminal signals, and send the transmitting terminal signal and the receiving terminal signal that have the same sampling rate after corrected to an echo cancellation system to carry out echo cancellation. The present invention can improve the quality of echo cancellation, simplify the computation and reduce the cost. The method for sampling rate mismatch correction of transmitting and receiving terminals provided in the embodiments of the invention comprises: calculating a transfer function of a receiving terminal signal relative to a transmitting terminal signal at each sampling timing according to the transmitting and receiving terminal signals; obtaining a transmission time delay of the transmitting and receiving terminals at each sampling timing using the transfer function; obtaining a sampling rate mismatch of the transmitting and receiving terminals at each sampling timing by means of parameter fitting using the transmission time delay and the linear relationship between the transmission time delay and the sampling rate mismatch; and adjusting the sampling rate of the transmitting terminal signal or the receiving terminal signal at each sampling timing according to the sampling rate mismatch. | 08-21-2014 |
20140254791 | Control and Management of Power Saving Link States in Vectored TDD Transmission Systems - An apparatus comprising a first transceiver unit (TU) for coupling to a first subscriber line, at least one next TU for coupling to at least one next subscriber line, and a processor coupled to the first TU and the at least one next TU, wherein the processor is configured to determine a link state in which data transmission is disabled for the duration of one or more symbols in a superframe, instruct the first TU to operate in the determined link state, and coordinate data transmission by the first TU and the at least one next TU to avoid an increase of crosstalk from the first line to the at least one next subscriber line due to the first TU operating in the determined link state. | 09-11-2014 |
20150023494 | VECTORED DSL CROSSTALK CANCELLATION - A vector DSL system includes a plurality of modems, which may be multi-port devices. Unprocessed user data is extracted from the modems and passed through a private vectoring data routing apparatus to one or more vectoring modules, such as vectoring cards. Each vectoring module includes one or more vector processors that include processing units configured to process the unprocessed user data on the basis of all modems' data for a given DSL tone grouping. Processing of the unprocessed user data removes the effects of FEXT from upstream and downstream user data and returns the processed user data to the modems using the vectoring data routing apparatus, which can be a specialized data transmission network utilizing one or more vector routers. | 01-22-2015 |
20150063560 | METHODS AND SYSTEMS FOR ACTIVATING AND DEACTIVATING COMMUNICATION PATHS - At least one example embodiment discloses a method of initializing a plurality of communication paths in a system. The method includes obtaining a first matrix from a storage medium, the first matrix including at least one channel sub-matrix of the system associated with a subset of the plurality of communication paths, obtaining an indication of which communication paths are to become active and determining, after the obtaining the indication, new compensation coefficients based on the at least one channel sub-matrix and active compensation coefficients, the active compensation coefficients for compensating for crosstalk between the active communication paths prior to the number of active communication paths changing. | 03-05-2015 |
20150350415 | METHODS AND SYSTEMS FOR DETERMINING CROSSTALK FOR A JOINING LINE IN A VECTORED SYSTEM - At least one example embodiment discloses a method of determining crosstalk for a joining line in a communication system having a plurality of current active lines. The method includes obtaining a number of disturber lines among the plurality of current active lines, the number of disturber lines being less than a number of the plurality of current active lines, obtaining a pilot matrix, a first dimension of the pilot matrix being based on the number of disturber lines, the pilot matrix representing a sequence of pilots to be transmitted across the plurality of current active lines and the joining line, the first dimension being a number of time instances, the number of time instances being less than the number of the plurality of active lines and determining a crosstalk coupling vector for the joining line based on the pilot matrix. | 12-03-2015 |
20160094273 | Power Spectrum Density Optimization - A method comprising allocating one or more detection tones of a sync symbol for crosstalk-free feedback data estimation, wherein the one or more detection tones are a quiet signal; transmitting the one or more detection tones to a computing device, receiving the crosstalk-free feedback data from the computing device, wherein the crosstalk-free feedback data comprises data associated with a background noise detected during the detection tones; determining an optimized PSD based at least in part on the crosstalk-free feedback data; and adjusting a transmission PSD of a plurality of tones based at least in part on the optimized PSD. | 03-31-2016 |
20160105216 | LINE INITIALIZATION METHOD, DEVICE, AND SYSTEM - Embodiments of the present invention provide a line initialization method, a device, and a system. The method includes: when a new line is added, releasing at least one resource unit that is on a line at a Showtime stage, so that on the line at the Showtime stage data is transmitted on a remaining resource unit that is obtained after the at least one resource unit is released; performing basic initialization on the new line by using the at least one resource unit or a subset of the at least one resource unit, so that after the basic initialization, data can be transmitted on the new line by using the at least one resource unit or the subset of the at least one resource unit; and performing crosstalk cancellation initialization on the line at the Showtime stage and the new line by using all resource units. | 04-14-2016 |
20160173682 | SYSTEMS AND METHODS FOR DETERMINING NON-LINEAR PRECODING COEFFICIENTS | 06-16-2016 |
20160205264 | LOW POWER SYSTEM AND METHOD FOR DSL LINES | 07-14-2016 |