Abstract: A method comprising modulating a plurality of synchronized signals by an orthogonal probe sequence (OPS) to generate a plurality of modulated synchronized signals, wherein the OPS comprises a zero element (0-element) column that indicates a start or an end of the OPS, and concurrently transmitting, using one or more transmitters, the plurality of modulated synchronized signals over a duration of a number of discrete multi-tone (DMT) symbols, wherein each of the plurality of modulated synchronized signals is intended for one of a plurality of receivers that are remotely coupled to the one or more transmitters via a vectored group of subscriber lines, and wherein the 0-element column causes all of the plurality of modulated synchronized signals to have a zero-amplitude during a first or a last of the DMT symbols.

Abstract: A method in a time-division duplex (TDD) transceiver coupled to a subscriber line, the method comprising receiving a discrete multitone (DMT) signal from a second transceiver after a period of inactivity on the subscriber line, wherein the DMT signal comprises a plurality of pilot tones, and determining a timing offset between the transceiver and the second transceiver based on the plurality of pilot tones.

Abstract: A method of discontinuous transmission data communication in a digital subscriber line (DSL) transceiver unit, the method comprising determining that a number of a plurality of bits available to transmit is enough to fill a data transfer unit (DTU), forming a DTU, by a DTU framer, comprising the plurality of bits, transferring the DTU to a retransmission queue, and determining the DTUs from the retransmission queue to be transmitted over a next time period used for transmitting over the DSL subscriber line by the DSL transceiver unit.

Abstract: A method of coordinating a plurality of transceiver units (TUs), the method comprising receiving an initialization intent notification from a first TU in the plurality of TUs, sending a low-power link state (LPLS) transition notification to a second TU in the plurality of TUs, receiving a LPLS transition complete notification from the second TU in response to the second TU transitioning from a first mode to a second mode, wherein in the first mode the second TU is in an LPLS with a long inactivity period (LPLS-L), sending an able to initialize notification to the first TU, and performing a vector training procedure using the first TU and the second TU.

Abstract: A transmitter for performing multicarrier modulation comprising a processing unit configured to generate a multicarrier data signal comprising a plurality of subcarriers, wherein each of the plurality of subcarriers represents at least one data bit of a plurality of data bits, select a subset of the subcarriers based on signal quality information about one or more of the subcarriers, construct a kernel signal comprising the subset of subcarriers, and create a digital signal comprising combining the multicarrier data signal and a peak-to-average ratio (PAR) reduction signal based on the kernel signal, wherein a PAR of the digital signal is less than a PAR of the multicarrier data signal.

Abstract: 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.

Abstract: Disclosed is an apparatus that includes a plurality of parallel digital signal transmitters that each receive one of a plurality of digital sub-signals wherein each of the plurality of digital signal transmitters is configured to transmit one of the plurality of digital sub-signals that each have about the same bandwidth. The apparatus also includes a combiner coupled to the transmitters and configured to shift some of the plurality of digital sub-signals and to combine the plurality of shifted digital sub-signals into a combined digital signal that has a total bandwidth of that is approximately equal to the sum of the bandwidths of the plurality of digital sub-signals. The total bandwidth comprises a plurality of shifted bandwidths of the plurality of digital sub-signals at about the same offset with respect to each other. The combined digital signal is transmitted over a digital subscriber loop.

Abstract: A transmitter for performing multicarrier modulation comprising a processing unit configured to generate a multicarrier data signal comprising a plurality of subcarriers, wherein each of the plurality of subcarriers represents at least one data bit of a plurality of data bits, select a subset of the subcarriers based on signal quality information about one or more of the subcarriers, construct a kernel signal comprising the subset of subcarriers, and create a digital signal comprising combining the multicarrier data signal and a peak-to-average ratio (PAR) reduction signal based on the kernel signal, wherein a PAR of the digital signal is less than a PAR of the multicarrier data signal.

Abstract: An apparatus comprising an input, a control signal generator coupled to the input and having a control signal generator output, and an amplifier coupled to the control signal generator output, wherein a voltage supplied to the amplifier is switched based on the control signal generator output, and wherein the control signal generator output is based on a data signal in the input. Also included is an apparatus comprising circuitry configured to implement a method comprising detecting an incoming signal, calculating a derivative of the incoming signal, estimating a future incoming signal based on the derivative of the incoming signal and a time step, and providing the estimated future incoming signal to switch between a first supply voltage and a second supply voltage prior to or concurrent with an arrival of the future incoming signal at the switch, wherein the incoming signal and the future incoming signal are analog signals.

Abstract: Disclosed is an apparatus that includes a plurality of parallel digital signal transmitters that each receive one of a plurality of digital sub-signals wherein each of the plurality of digital signal transmitters is configured to transmit one of the plurality of digital sub-signals that each have about the same bandwidth. The apparatus also includes a combiner coupled to the transmitters and configured to shift some of the plurality of digital sub-signals and to combine the plurality of shifted digital sub-signals into a combined digital signal that has a total bandwidth of that is approximately equal to the sum of the bandwidths of the plurality of digital sub-signals. The total bandwidth comprises a plurality of shifted bandwidths of the plurality of digital sub-signals at about the same offset with respect to each other. The combined digital signal is transmitted over a digital subscriber loop.

Abstract: An apparatus comprising an artificial noise (AN) controller coupled to a digital subscriber line (DSL) transmitter and configured to adjust an AN level for a signal transmitted by the DSL transmitter, wherein the AN level is adjusted based on an actual signal to noise ratio (SNR) of the signal from the receiver to achieve a desired SNR for the signal. Also disclosed is a method comprising maintaining a data rate in a line at about a desired level by adjusting an AN level in a transmitted signal based on a SNR of a received signal.

Abstract: An apparatus comprising an input, a control signal generator coupled to the input and having a control signal generator output, and an amplifier coupled to the control signal generator output, wherein a voltage supplied to the amplifier is switched based on the control signal generator output, and wherein the control signal generator output is based on a data signal in the input. Also included is an apparatus comprising circuitry configured to implement a method comprising detecting an incoming signal, calculating a derivative of the incoming signal, estimating a future incoming signal based on the derivative of the incoming signal and a time step, and providing the estimated future incoming signal to switch between a first supply voltage and a second supply voltage prior to or concurrent with an arrival of the future incoming signal at the switch, wherein the incoming signal and the future incoming signal are analog signals.

Abstract: An apparatus comprising an artificial noise (AN) controller coupled to a digital subscriber line (DSL) transmitter and configured to adjust an AN level for a signal transmitted by the DSL transmitter, wherein the AN level is adjusted based on an actual signal to noise ratio (SNR) of the signal from the receiver to achieve a desired SNR for the signal. Also disclosed is a method comprising maintaining a data rate in a line at about a desired level by adjusting an AN level in a transmitted signal based on a SNR of a received signal.

Abstract: To reduce the ISDN crosstalk in an incoming DSL signal, a crosstalk canceller observes at least a portion of the crosstalk signal and reproduces an estimate of the crosstalk signal for at least a portion of that signal within the DSL band. The crosstalk canceller applies a canceling signal based on the estimated crosstalk signal to reduce the crosstalk in the received DSL signal.

Abstract: An echo cancellation (EC) system for use in a full-duplex communication system having asymmetric signal sampling rates, in particular an ADSL system, is described. The system performs the cancellation of local echo signal in digital or analog domain depending on the loop condition using a switching logic. The EC system further includes an EC unit that generates a digital echo estimate signal at the lower sampling rate of the transmitted signal and then interpolates the digital signal to higher sampling rate to cancel echo signal thereby reducing computation complexity. The digital interpolated echo estimate signal is converted to analog form for use in analog echo cancellation. The subtracted signal resulting from the analog echo cancellation is converted into digital domain and used as feedback for the EC unit to adaptively improve the accuracy of the echo estimate.

Abstract: To reduce the ISDN crosstalk in an incoming DSL signal, a crosstalk canceller observes at least a portion of the crosstalk signal and reproduces an estimate of the crosstalk signal for at least a portion of that signal within the DSL band. The crosstalk canceller applies a canceling signal based on the estimated crosstalk signal to reduce the crosstalk in the received DSL signal.