Abstract: An input estimator is based on a combined MFDQ-DF and trellis for use in, for example, an ADSL environment. In particular, for an ADSL implementation, the system will have one feedback tap for the decision feedback. However, it should be appreciated that the idea and basic concept of using the structure of a trellis to aid in determining the feedback point can be extended to any system using a feedback equalizer to estimate input to a trellis decoder.

Abstract: An echo cancellation device relies on the known characteristics of the sync frame to monitor, update in an off-line fashion and determine the accuracy of an echo canceller in, for example, a modem, such as an ADSL modem. Specifically, time domain samples are read from the transmit (Tx) and receive (Rx) paths of the modem. These samples are stored in memory. When the sync frame has received a predetermined number of the same Tx samples and Rx samples, the samples are stored. Running averages, over the sync frames, of the TX and RX samples are maintained. These averages are subtracted from a sync frame of samples, to allow LMS updating of the echo canceller taps, free of extraneous signals. Updating, i.e., tracking of changes in the echo channel, is done for the echo canceller in an off-line fashion. The coefficients for the in-line version are updated, while the off-line version is updated over several sync frames. Periodically, the performance of the off-line version is compared with the in-line version.

Abstract: Through the use of feedback in determining frequency domain equalization, intersymbol interference can be reduced. Specifically, the determined constellation point closest to the determined received point can be fed back to aid in determining one or more other closest constellation points.

Abstract: An input estimator is based on a combined MFDQ-DF and trellis for use in, for example, an ADSL environment. In particular, for an ADSL implementation, the system will have one feedback tap for the decision feedback. However, it should be appreciated that the idea and basic concept of using the structure of a trellis to aid in determining the feedback point can be extended to any system using a feedback equalizer to estimate input to a trellis decoder.

Abstract: Through the use of feedback in determining frequency domain equalization, interference can be reduced. Specifically, the determined constellation point closest to the determined received point can be fed back to aid in determining one or more other closest constellation points.

Abstract: Through the use of feedback in determining frequency domain equalization, intersymbol interference can be reduced. Specifically, the determined constellation point closest to the determined received point can be fed back to aid in determining one or more other closest constellation points.

Abstract: Using a known or later developed time domain equalizer coefficient training algorithm, a least square solution for the time domain equalizer coefficients is taken at a starting point and iteratively improved on. In particular, the improvement is directed towards maximizing number of bits per frame loaded over the time domain equalizer coefficient choice. This can be accomplished by maximizing capacity directly rather than setting a goal to shorten the channel and hoping that the capacity will be maximized as a result.

Abstract: Through the use of feedback in determining frequency domain equalization, intersymbol interference can be reduced. Specifically, the determined constellation point closest to the determined received point can be fed back to aid in determining one or more other closest constellation points.

Abstract: An input estimator is based on a combined MFDQ-DF and trellis for use in, for example, an ADSL environment. In particular, for an ADSL implementation, the system will have one feedback tap for the decision feedback. However, it should be appreciated that the idea and basic concept of using the structure of a trellis to aid in determining the feedback point can be extended to any system using a feedback equalizer to estimate input to a trellis decoder.

Abstract: Using a known or later developed time domain equalizer coefficient training algorithm, a least square solution for the time domain equalizer coefficients is taken at a starting point and iteratively improved on. In particular, the improvement is directed towards maximizing number of bits per frame loaded over the time domain equalizer coefficient choice. This can be accomplished by maximizing capacity directly rather than setting a goal to shorten the channel and hoping that the capacity will be maximized as a result.

Abstract: An echo cancellation device relies on the known characteristics of the sync frame to monitor, update in an off-line fashion and determine the accuracy of an echo canceller in, for example, a modem, such as an ADSL modem. Specifically, time domain samples are read from the transmit (Tx) and receive (Rx) paths of the modem. These samples are stored in memory. When the sync frame has received a predetermined number of the same Tx samples and Rx samples, the samples are stored. Running averages, over the sync frames, of the TX and RX samples are maintained. These averages are subtracted from a sync frame of samples, to allow LMS updating of the echo canceller taps, free of extraneous signals. Updating, i.e., tracking of changes in the echo channel, is done for the echo canceller in an off-line fashion. The coefficients for the in-line version are updated, while the off-line version is updated over several sync frames. Periodically, the performance of the off-line version is compared with the in-line version.

Abstract: An echo cancellation device relies on the known characteristics of the sync frame to monitor, update in an off-line fashion and determine the accuracy of an echo canceller in, for example, a modem, such as an ADSL modem. Specifically, time domain samples are read from the transmit (Tx) and receive (Rx) paths of the modem. These samples are stored in memory. When the sync frame has received a predetermined number of the same Tx samples and Rx samples, the samples are stored. Running averages, over the sync frames, of the TX and RX samples are maintained. These averages are subtracted from a sync frame of samples, to allow LMS updating of the echo canceller taps, free of extraneous signals. Updating, i.e., tracking of changes in the echo channel, is done for the echo canceller in an off-line fashion. The coefficients for the in-line version are updated, while the off-line version is updated over several sync frames. Periodically, the performance of the off-line version is compared with the in-line version.

Abstract: A technique is provided that may be employed in multicarrier communications to improve the efficiency of error correction using symbol-oriented error correction methodologies, by reducing the number of error correction code symbols (102, 104 . . . ) that are received in error that result from a single channel error. More specifically, in this technique, bits from the symbols are allocated among the channels in such a way as to minimize the number of respective channels that are allocated bits belonging to more that one respective symbol during a respective transmission period.

Abstract: Through the use of feedback in determining frequency domain equalization, intersymbol interference can be reduced. Specifically, the determined constellation point closest to the determined received point can be fed back to aid in determining one or more other closest constellation points.

Abstract: Through the use of feedback in determining frequency domain equalization, intersymbol interference can be reduced. Specifically, the determined constellation point closest to the determined received point can be fed back to aid in determining one or more other closest constellation points.

Abstract: An input estimator is based on a combined MFDQ-DF and trellis for use in, for example, an ADSL environment. In particular, for an ADSL implementation, the system will have one feedback tap for the decision feedback. However, it should be appreciated that the idea and basic concept of using the structure of a trellis to aid in determining the feedback point can be extended to any system using a feedback equalizer to estimate input to a trellis decoder.

Abstract: Through the use of feedback in determining frequency domain equalization, intersymbol interference can be reduced. Specifically, the determined constellation point closest to the determined received point can be fed back to aid in determining one or more other closest constellation points.

Abstract: By comparing the measured data of a transmission line to a model of the transmission line comprising models of each individual portion of the line, an estimation of the loop can be determined. Specifically, the transmission line can be modeled by a model of the transmit filter, a model of the receive filter, a model of the analog hybrid circuitry and an ABCD matrix model of the loop.

Abstract: A communication system having a modulation system for transmitting a symbol set via a single side-band modulated carrier and a demodulation system for recovering the in-phase and quadrature signals from the modulated carrier. The modulation circuit receives M symbol values and generates M time domain samples for each of the in-phase and quadrature signals. The in-phase and quadrature signals can then be combined to generate the single side-band modulated carrier. The modulation circuit includes a transform circuit for generating M transformed symbol values by computing the transform of the M symbol values. A polyphase filter bank having 2M FIR filters is used to process the output of the transform circuit. Each filter has g taps, where g is an integer greater than 1. The outputs of the polyphase filters are combined with the outputs of the polyphase filters generated from a previously received set of M symbols to generate the M time-domain signal values of the in-phase signal.