Broadcom Corporation

Avago Technologies International Sales Pte. Limited

Robindra B Joshi

Thuji Simon Lin

Thomas J Kolze

Bruce Joseph Currivan

Ramon Alejandro Gomez

Steven T Jaffe

Leonard Dauphinee

Loke Kun Tan

Lin He

Young J Shin

Francesco Gatta

Hanli Zou

Massimo Brandolini

Binning Chen

Robert A Hawley

Huan-Chang Liu

Jeffrey Scott Putnam

Paul T Yang

David Jones

Martin Kuhlmann

Method and apparatuses are disclosed to substantially compensate for various unwanted interferences and/or distortions within a communications receiver. Each of these apparatuses and methods estimate the various unwanted interferences and/or distortions within the communications receiver. Each of these apparatuses and methods remove the estimates of the various unwanted interferences and/or distortions within the communications receiver from one or more communications signals within the communications receiver to substantially compensate for the various unwanted interferences and/or distortions.

Compensating for unwanted interference in a communications receiver

Selectable interference cancellation in a communications receiver

Compensating for unwanted distortion in a communications receiver

Configurable adaptive filter

A method of compensating for carrier frequency and phase errors of a received multi-carrier modulated signal. The received multi-carrier signal including modulated carriers for transmitting known data and unmodulated carriers for error correction, comprising, time domain down converting the received multi-carrier signal to base-band to provide a down-converted signal, the down-converted signal including a plurality of modulated carriers for transmitting known data and unmodulated carriers for error correction. Sampling an unmodulated carrier of the down-converted signal to provide received data samples. Providing a reference signal derived from the unmodulated carrier of the down-converted signal. And, estimating phase errors from a phase difference between the ummodulated carrier and the reference signal derived from the unmodulated carrier of the down-converted signal to provide a plurality of received sample phase error estimates for each modulated carrier.

System and method for multi-carrier modulation

A device of dynamic communication of information allows, on the average, non-integer bits per symbol transmission, using a compact code set or a partial response decoding receiver. A stream of selectable predetermined integer bits, e.g., k or k+1 data bits, is grouped into a selectable integer number of bit vectors which then are mapped onto corresponding signal constellations forming transmission symbols. Two or more symbols can be grouped and further encoded, so that a symbol is spread across the two or more symbols being communicated. Sequence estimation using, for example, maximum likelihood techniques, as informed by noise estimates relative to the received signal. Each branch metric in computing the path metric of a considered sequence at the receiver is weighted by the inverse of the noise power. It is desirable that the constellation selection, sequence estimation and noise estimation be performed continuously and dynamically.

Constellation-multiplexed transmitter and receiver

A feedforward filter has a plurality of feedforward filter taps, including a feedforward filter reference tap. The reference tap of the feedforward filter is positioned proximate a center position of the feedforward filter. A ramping circuit assembly has an input port configured to receive at least one decision feedback filter tap coefficient from a decision feedback filter. A coefficient ramping circuit is configured to provide a ramped output for at least one of the decision feedback filter tap coefficients. The ramped output is varied over time from a first value to a second value. The second value is dependent upon the value of a decision feedback filter tap coefficient. An output port of the ramping circuit assembly is configured to communicate information representative of the ramped output(s) to a precoder.

Decision feedback equalizer and precoder ramping circuit

A communication unit () arranged to send transmit data includes a receiver () arranged to recover input data transmitted at a downstream transfer rate in response to a symbol clock () signal. A transmitter () is arranged to transmit the transmit data at an upstream transfer rate in response to an upstream transmit clock signal (TX_CLKA) that is coordinated with the symbol clock signal. The frequency or repetition rate of the upstream transmit clock signal is defined at least in part by a predetermined relationship between the downstream transfer rate and the upstream transfer rate, such as a ratio of the downstream transfer rate and the upstream transfer rate.

Communication timing coordination techniques

Clock signals and digital data signals at a variable frequency are introduced to the input of a FIFO and are passed from the FIFO at a second (or intermediate) frequency controlled by a numerically controlled oscillator. To regulate the frequency of the signals from the numerically controlled oscillator, the phases of the clock signals at the variable frequency are compared in a phase detector with the phases of the signals from the numerically controlled oscillator to generate an error signal. The error signals and the signals at a fixed sampling frequency higher than the intermediate frequency regulate the frequency of the signals from the numerically controlled oscillator and thus the frequency of the digital data signals from the FIFO. The digital data signals from the FIFO are converted to a pair of signals at the second frequency. The pair of signals at the second frequency have individual ones of a plurality of analog levels dependent upon a code indicated by successive pairs of the digital data signals. The signals at the second (or intermediate) frequency modulate a pair of trigonometrically related signals at the fixed sampling frequency. The modulated signals at the fixed sampling frequency are combined and the combined signals are sampled at the fixed sampling frequency to corresponding analog values by a digital-to-analog converter.

Variable rate modulator

A device of dynamic communication of information allows, on the average, non-integer bits per symbol transmission, using a compact code set or a partial response decoding receiver. A stream of k or k&plus;1 data bits is grouped into bit vectors which then are mapped onto corresponding signal constellations forming transmission symbols. Two or more symbols can be grouped and further encoded, so that a symbol is spread across the two or more symbols being communicated. Sequence estimation using, for example, maximum likelihood techniques, as informed by noise estimates relative to the received signal. Each branch metric in computing the path metric of a considered sequence at the receiver is weighted by the inverse of the noise power. It is desirable that the constellation selection, sequence estimation and noise estimation be performed continuously and dynamically.

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Laguna Niguel, CA, United States of America

Robindra B Joshi