Abstract: A method, system and apparatus for decreasing the time frame synchronization and resynchronization in a data communication uses an long frame sync word formed by combining a frame sync word with stuff bits, wherein the stuff bits are necessary for timing adjustments.

Abstract: In a data communication system having a channel with time-varying impairments and further having a transmitter with a precoder, a method and apparatus for updating the precoder coefficients. The method and apparatus is based on the arrangement of a duplicate precoder and correction filter in the receiver, where the correction filter generates incremental coefficients. The incremental coefficients are sent via a back channel to the transmitter and added to the current values of the precoder coefficients. The method and apparatus provide DFE-like performance and do not have the delay problems associated with DFEs.

Abstract: The present invention relates to an improved method and apparatus for echo cancellation in a communication system utilizing a bidirectional transmission medium. The invention significantly reduces computational overhead associated with echo cancellation by using sub-Nyquist sampling in the echo path. In particular, the invention relates to a method and apparatus for echo cancellation in a communication system utilizing different signaling or baud rates in the transmit and receive directions, whereby the computational overhead of the echo cancellation is significantly reduced as compared to traditional methods. In a preferred embodiment herein, the present invention reduces by one-half the computational overhead associated with echo cancellation in a data communications system utilizing symmetrical information rates at asymmetrical signal rates.

Abstract: The present invention is a communication system for communicatinginformation over greater distances than otherwise possible on bidirectional media subject tointerference, by reducing the interference while assuring spectral compatibility with other communication services. The system of the present invention provides symmetric data service to end users by using asymmetric signaling. In one embodiment, the present invention utilizes partially overlapped, non-symmetric baud rates and spectrally shaped transceiver filters to achieve both spectral compatibility and extended range.