Abstract: A method for transmitting a stream of data over a channel made up of a plurality of subchannels having respective subchannel rates. The method includes partitioning the data among the subchannels, such that successive words of the data are mapped to the subchannels in alternation responsive to the respective subchannel rates. The words of the data are transmitted over the subchannels to which they are mapped, and are then received and processed to recover the stream of data.

Abstract: An interpolation filter for processing a sequence of input samples provided at an input rate controlled by an input clock, so as to generate interpolants at an output rate controlled by an output clock, which is substantially independent of the input clock. The filter includes a plurality of stages arranged in a succession in which each of the stages, except for a first stage in the succession, is coupled respectively to a preceding one of the stages.

Abstract: A method for conveying digital data from a transmitter to a receiver includes specifying a spectral filtering profile to be applied in conveying the data. A sequence of input symbols is generated at the transmitter, corresponding to the data to be conveyed. The input symbols are precoded at the transmitter using Tomlinson-Harashima preceding responsive to the specified profile, so as to generate a corresponding sequence of precoded symbols. The precoded symbols are filtered in accordance with the specified profile. The precoded and filtered symbols are decoded at the receiver so as to recover the data therefrom.

Abstract: A method for decoding a sequence of symbols encoded by an encoding system with a plurality of possible states and transmitted over a channel, wherein the encoding system output can be represented by a trellis diagram. The method includes receiving a signal corresponding to the sequence of symbols transmitted over the channel and responsive to the signal, finding respective old state metrics for one or more of the possible states of the encoding system that correspond to a given symbol in the sequence. Respective transition metrics are determined for state transitions that link the one or more possible states for which the old state metrics were found to at least some of the possible states of the encoding system that correspond to a succeeding one of the symbols in the sequence.

Abstract: A high-speed receiver, adapted to receive signals over an input line in the presence of narrowband radio frequency interference (RFI). The receiver includes a RFI canceller module, which is coupled to receive samples of the interference from the input line. The module includes an adaptive bandpass filter, which is adapted to track a dominant frequency of the interference, and to generate a filtered output in a narrow frequency range centered on the dominant frequency. A corrector is coupled to receive the filtered output from the adaptive bandpass filter and to generate, responsive thereto, an estimate of the interference in the signals received by the receiver. A subtractor is adapted to subtract the estimate of the interference from the signals received by the receiver so as to generate a corrected output signal.

Abstract: A method for transmitting a succession of input data samples over a channel having a given channel response includes generating a set of candidate signal point sequences responsive to the input data samples, such that the input data samples are recoverable from a final signal derived from the candidate sequences. The succession of input data samples is mapped into a succession of interim signal point sequences, selected from among the candidate signal point sequences according to a signal shaping criterion. The interim signal point sequences are precoded according to the given channel response and further according to a whitening transformation. The precoded sequences are filtered in accordance with the whitening transformation, thus generating the final signal to be transmitted over the channel to a receiver.

Abstract: A method for transmitting a stream of data over a channel made up of a plurality of subchannels having respective subchannel rates. The method includes partitioning the data among the subchannels, such that successive words of the data are mapped to the subchannels in alternation responsive to the respective subchannel rates. The words of the data are transmitted over the subchannels to which they are mapped, and are then received and processed to recover the stream of data.

Abstract: An interpolation filter for processing a sequence of input samples provided at an input rate controlled by an input clock, so as to generate interpolants at an output rate controlled by an output clock, which is substantially independent of the input clock. The filter includes a plurality of stages arranged in a succession in which each of the stages, except for a first stage in the succession, is coupled respectively to a preceding one of the stages.

Abstract: A receiver for high-speed data communications, which receives a differential signal through a pair of signal lines. The receiver includes a common-mode choke, which has first and second signal windings, which are respectively coupled in series to the pair of signal lines so as to attenuate common-mode interference in the differential signal. The choke also has a sampling winding, which is inductively coupled to the signal windings so as to generate a sampled signal responsive to current flowing in the signal windings. Signal processing circuitry is coupled to receive the sampled signal from the sampling winding and to receive the differential signal from the signal windings and to process the differential signal responsive to the sampled signal.

Abstract: A method is described for mapping digital input data, including a sequence of input samples, into an interim signal point sequence, for use in conjunction with a single carrier modulation transmitter. The method includes generating a set of candidate signal point sequences, for each input sample, selecting an interim signal point sequence, into which to map the sequence of input samples, from among the set of candidate signal point sequences, so as to obtain a low peak power value of a final signal generated from the interim signal point sequence, and using a single carrier modulation transmitter to transmit the final signal to a receiver.

Abstract: A high-speed transmitter, which generates an output signal stream having a specified spectral profile. The transmitter includes a Tomlinson-Harashima precoder, which is adapted to receive a sequence of input symbols having a given input constellation and to generate, responsive to the specified spectral profile, a corresponding sequence of precoded symbols. A transmit digital filter is adapted to apply a transmit filter response, in accordance with the specified spectral profile, to the precoded symbols so as to generate a corresponding sequence of output symbols, having a given output constellation, to be transmitted in the output stream.