Abstract: A method and apparatus for providing a precoder filter having peak-to-average ratio (PAR) controller that also serves as a high-pass, low-pass, or band-pass filter. The described invention is includes a modulo device connected in series with the PAR controller and a precoder filter connected in a feedback arrangement. The input to the apparatus is a sequence of data symbols and the output is a spectrally shaped precoded signal having a controlled peak-to-average ratio.

Abstract: A system, method, and apparatus for increasing the data rate on an existing repeatered telecommunication channel structure. In illustrative embodiments, replacement transceivers and replacement repeaters provide for transferring data streams via the existing channel structure at a rate substantially greater than the data transfer rate of the existing channel structure. The replacement transceivers and replacement repeaters are spectrally compatible with existing services and provide data transfer performance equal to or better than the performance of the existing channel structure.

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.