Abstract: An OFDM receiver comprises a (FEC) decoder and a nonlinearity compensation circuit. The nonlinearity compensation circuit is operable to generate estimates of constellation points transmitted on each of a plurality of subcarriers of a received signal based on soft decisions from the FEC decoder and based on a model of nonlinear distortion introduced by a transmitter from which the received signal was received. The generation of the estimates may be based on a measure of distance between a function of the received signal and a synthesized version of the received signal. The generation of the estimates may comprise iterative processing of symbols of the received signal, and the iterative processing may comprise a plurality of outer iterations and a plurality of inner iterations.

Abstract: In a wireless transmission system including a transmit delay module, delaying each of at least one copy of a signal by a respective delay, the signal being transmitted over a plurality of carrier frequencies and over at least one beam, the at least one beam exhibiting a beam pattern, the number of copies of the signal corresponding to the number of beams, each the at least one copy being associated with a respective one of the at least one beam, the system further including a beam pattern former, coupled with the transmit delay module, producing a plurality of transmit signals corresponding to the beam pattern, a frequency dependent beam shifter, coupled with the beam pattern former, delaying each of the at least one transmit signal by a respective angular shift delay, thereby applying an angular shift to each of the at least one beam, the angular shift of each of the at least one beam corresponding to at least a respective one of the carrier frequencies, wherein each beam is transmitted with a delay correspo

Abstract: Methods and systems provide an efficient power save mode for multi carrier modems, such as DMT based ADSL and VDSL modems. Fast transitions from power save mode to full operational mode occur, without the overhead of transmitting large quantities of configuration information between the transmitter and receiver. Signal constellation size changes occurring while operating in power save mode to continue to apply once full operational mode is resumed. Multiple power save modes are enabled, each having a different level of power dissipation and crosstalk, both far end crosstalk and near end crosstalk. Power dissipation and crosstalk can thus be graduated on a line, according to a user-requested bit rate.

Abstract: Apparatus for interference budgeting at base stations of a wireless network wherein mobile units communicate with a current base station but may cause interference to neighboring base stations, comprises: an extraction unit for extracting, from signals received at said current base station in relation to respective mobile units, an interference indication; and an uplink management unit for controlling the uplink to mobile units, wherein said management unit is connected to said extraction unit to obtain respective interference indications, thereby to use said respective interference indications as constraints when allocating said uplink resources. The resource may be uplink power or an uplink frequency channel that is allocated to different mobile stations and/or it may be interference budget that is allocated between base stations.

Abstract: In a wireless transmission system including a transmit delay module, delaying each of at least one copy of a signal by a respective delay, the signal being transmitted over a plurality of carrier frequencies and over at least one beam, the at least one beam exhibiting a beam pattern, the number of copies of the signal corresponding to the number of beams, each the at least one copy being associated with a respective one of the at least one beam, the system further including a beam pattern former, coupled with the transmit delay module, producing a plurality of transmit signals corresponding to the beam pattern, a frequency dependent beam shifter, coupled with the beam pattern former, delaying each of the at least one transmit signal by a respective angular shift delay, thereby applying an angular shift to each of the at least one beam, the angular shift of each of the at least one beam corresponding to at least a respective one of the carrier frequencies, wherein each beam is transmitted with a delay correspo

Abstract: Disclosed is a method, circuit and system for transmission and reconstruction of a video block. A video stream may be composed of sequential video frames, and each video frame may be composed of one or more video blocks including a set of pixels. Prior to transmission of the data associated with a video block, the video block data may be transformed into a set of transform (e.g. frequency) coefficients using a spatial to frequency transform such as a two dimensional discrete cosine transform. Selection of the subset of transform coefficients to be transmitted may be based on a characteristic of the video block.

Abstract: A method for digital communication includes generating time-domain symbols having a predetermined symbol duration in accordance with a discrete multi-tone (DMT) modulation scheme. A cyclic extension is added to each of the time-domain symbols so as to form data blocks having a block length that is not an integer multiple of the symbol duration. A training pattern is generated on one or more tones of the DMT modulation scheme, wherein the training pattern is periodic over a sequence of the data blocks with a period equal to the symbol duration. The sequence of the data blocks is transmitted over a communication channel to a receiver, which processes the training pattern so as to determine a response of the channel to the one or more tones.

Abstract: A receiver for receiving an incoming signal over a communication medium includes an echo canceller, which is adapted to receive an outgoing signal transmitted over the communication medium, and to process the outgoing signal using a set of variable processing coefficients in order to generate an echo cancellation signal. A summer combines the incoming signal with the echo cancellation signal so as to generate an echo-cancelled signal. An equalizer applies an equalization operation to the echo-cancelled signal so as to generate an equalized signal. A residual echo cancellation circuit processes the equalized signal so as to adaptively update the variable processing coefficients of the echo canceller.

Abstract: Methods and systems provide an efficient power save mode for multi carrier modems, such as DMT based ADSL and VDSL modems. Fast transitions from power save mode to full operational mode occur, without the overhead of transmitting large quantities of configuration information between the transmitter and receiver. Signal constellation size changes occurring while operating in power save mode to continue to apply once full operational mode is resumed. Multiple power save modes are enabled, each having a different level of power dissipation and crosstalk, both far end crosstalk and near end crosstalk. Power dissipation and crosstalk can thus be graduated on a line, according to a user-requested bit rate.

Abstract: A method for digital communication includes generating time-domain symbols having a predetermined symbol duration in accordance with a discrete multi-tone (DMT) modulation scheme. A cyclic extension is added to each of the time-domain symbols so as to form data blocks having a block length that is not an integer multiple of the symbol duration. A training pattern is generated on one or more tones of the DMT modulation scheme, wherein the training pattern is periodic over a sequence of the data blocks with a period equal to the symbol duration. The sequence of the data blocks is transmitted over a communication channel to a receiver, which processes the training pattern so as to determine a response of the channel to the one or more tones.

Abstract: A system for detecting and correcting impulse noise present on an input data signal includes an impulse detector module receiving an input data signal and producing as output an correction enable signal indicating when an impulse correction is required. An impulse corrector module receives the input data signal and a correction enable signal and produces a corrected data signal, e.g., having the impulse canceled or blanked, as output. A reliability estimator and selector module receives the corrected data signal and the input data signal and selects as output the input signal which is more reliable. In one embodiment, the impulse detector includes first and second complementary impulse detectors, the outputs of which are analyzed by an enable and correction module to produce an impulse detection signal with improved accuracy. Preferably, the enable and correction module also indicates the most appropriate type of impulse correction in accordance with the detection signals from the complementary detectors.

Abstract: A receiver for receiving an incoming signal over a communication medium includes an echo canceller, which is adapted to receive an outgoing signal transmitted over the communication medium, and to process the outgoing signal using a set of variable processing coefficients in order to generate an echo cancellation signal. A summer combines the incoming signal with the echo cancellation signal so as to generate an echo-cancelled signal. An equalizer applies an equalization operation to the echo-cancelled signal so as to generate an equalized signal. A residual echo cancellation circuit processes the equalized signal so as to adaptively update the variable processing coefficients of the echo canceller.

Abstract: A system for detecting and correcting impulse noise present on an input data signal includes an impulse detector module receiving an input data signal and producing as output an correction enable signal indicating when an impulse correction is required. An impulse corrector module receives the input data signal and a correction enable signal and produces a corrected data signal, e.g., having the impulse canceled or blanked, as output. A reliability estimator and selector module receives the corrected data signal and the input data signal and selects as output the input signal which is more reliable. In one embodiment, the impulse detector includes first and second complementary impulse detectors, the outputs of which are analyzed by an enable and correction module to produce an impulse detection signal with improved accuracy. Preferably, the enable and correction module also indicates the most appropriate type of impulse correction in accordance with the detection signals from the complementary detectors.