Broadcom Corporation

Scientific-Atlanta, Inc.

Kevin Lee Miller

Todd Lee Brooks

David S P Ho

Thomas J Kolze

Theodore F Rabenko

Ramin Borazjani

Bruce Joseph Currivan

Ramon Alejandro Gomez

Jonathan S Min

David Hartman

Anders Hebsgaard

Robert J Lee

Shane Patrick Lansing

James Chi Thi

Robert M Lukas

Kenneth J Unger

Eric Fogleman

Richard Stephen Prodan

Keith LaRell Klingler

Pieter Vorenkamp

Brian Francis Schoner

Fang Lu

Joel I Danzig

Arnoldus Venes

Josephus A Van Engelen

Steven L Caine

Charles Garrison Wier

John H Gleiter

Tak Kwan Lee

Chun-Ying Chen

Loke Kun Tan

Leo Montreuil

Xicheng Jiang

Donald George McMullin

Avraham Kliger

Massimo Brandolini

Thuji Simon Lin

Jeffrey Scott Putnam

Jiangfeng Wu

Ravi Bhaskaran

Mark Edward Laubach

Gopal Triplicane Venkatesan

Tianwei Li

James P Cavallo

Peter Cangiane

Joseph Leonard Laskowski

Hans Eberhart

Chung-Ying Chen

Ray Whitehead

H Ray Whitehead

Beth Wilcher

Hsin-An Liu

Donald Mcmullin

A communication device (e.g., a cable modem (CM)) includes a digital to analog converter (DAC) and a power amplifier (PA) that generate a signal to be transmitting via a communication interface to another communication device (e.g., cable modem termination system (CMTS)). The CM includes diagnostic analyzer that samples the signal based on a fullband sample capture corresponding to a full bandwidth and/or a subset (e.g., narrowband) sample capture to generate a fullband and/or subset signal capture (e.g., of an upstream (US) communication channel between the CM and the CMTS). The diagnostic analyzer can be configured to generate sample captures of the signal based on any desired parameter(s), condition(s), and/or trigger(s). The CM then transmits the signal to the CMTS and the fullband and/or subset signal capture to the CMTS and/or a proactive network maintenance (PNM) communication device to determine at least one characteristic associated with performance of the US communication channel.

Noise localization within cable based communication systems

A system is configured to facilitate bidirectional voice communication between a number of data and/or telephony devices.

Modem with voice processing capability

A communication device includes a communication interface, a number of variable power amplifiers (VPAs), and a processor. Some of the VPAs are configured to process analog signals to generate processed analog signals (e.g., each VPA configured to process one of the analog signals to generate one of the processed analog signals based on a respective VPA control signal). A composite VPA processes a summation of the processed analog signals, which are generated by certain of the VPA, to generate a processed composite signal based on a composite VPA control signal. The processor generates the a first, a second, and a composite VPA control signals based, at least in part, on configuration information from another communication device via the communication interface. The processor may be configured to consider other information as well, such as locally generated information (within the communication device), operational history, current operating conditions, etc.

Upstream power amplifier

A network gateway is configured to facilitate on line and off line bi-directional communication between a number of near end data and telephony devices with far end data termination devices via a hybrid fiber coaxial network and a cable modem termination system. The described network gateway combines a QAM receiver, a transmitter, a DOCSIS MAC, a CPU, a voice and audio processor, a voice synchronizer, an Ethernet MAC, and a USB controller to provide high performance and robust operation.

Highly power efficient transmitter output stage designs are provided. In an embodiment, the probability density function (PDF) of an input signal is divided into a plurality of regions, and samples of the input signal are processed depending on the region of the PDF within which they fall. The PDF can be divided between an inner region corresponding to samples of the input signal that are within a predetermined amplitude range, and outer regions corresponding to samples of the input signal that are outside of the predetermined amplitude range. Samples of the input signal that fall in the inner region are processed by a class A biased amplifier and samples of the input signal that fall in the outer regions are processed by a class B biased amplifier. Output stage designs according to embodiments can be implemented as power amplifiers or power digital-to-analog converters (DACs).

High efficiency output stage amplification for radio frequency (RF) transmitters

Provided are a method and system for a module for a cable modem termination system. The module includes a digital modulator configured to block up-convert a plurality of digital channels and a digital to analog converter coupled, at least indirectly, to an output of the digital modulator to convert the digital channels to an analog format.

Method and system for direct digital up-conversion in a cable modem

Distortion and aliasing reduction for digital to analog conversion. Synthesis of one or more distortion terms made based on a digital signal (e.g., one or more digital codewords) is performed in accordance with digital to analog conversion. The one or more distortion terms may correspond to aliased higher-order harmonics, distortion, nonlinearities, clipping, etc. Such distortion terms may be known a priori, such as based upon particular characteristics of a given device, operational history, etc. Alternatively, such distortion terms may be determined based upon operation of a device and/or based upon an analog signal generated from the analog to conversion process. For example, frequency selective measurements made based on an analog signal generated from the digital to analog conversion may be used for determination of and/or adaptation of the one or more distortion terms. One or more DACs may be employed within various architectures operative to perform digital to analog conversion.

Distortion and aliasing reduction for digital to analog conversion

Provided is a transmitter in a communications system including a plurality of digital to analog converters. Also included is a plurality of clocks, each being communicably coupled to a corresponding one of the digital to analog converters.

Method and system for time interleaved digital to analog conversion for a cable modem

In a high-fidelity digital modulator, a mapper is provided to minimize quantization noise, jitter, and cross-talk between multiple digital-to-analog or analog-to-digital converters. The mapper receives a quantized level from a quantizer and maps the quantized level to an output sequence. The mapper includes a table defining multiple sequences corresponding to each quantized level. Each sequence includes two or more symbols, having one of multiple values. The mapper also includes a generator that selects one of the multiple sequences as the output sequence. The last symbol of a first output sequence is equal to the first symbol of the next output sequence and so on. The generator selects the output sequence by alternating between a first and a second sequence for each quantized level received. The generator selects the output sequence by alternating between sequences having a positive and a negative common mode energy for each odd valued quantized level received.

Nonlinear mapping in digital-to-analog and analog-to-digital converters

A system and method are used to provide uncorrelated code hopping in a communications system. A shift register receives data. The shift register is clocked to shift the data. A scaler performs a scaling operation on the data with a numerical value of active codes. A truncator truncates the scaled data to its seven most significant bits to produce a pseudo random hop number. A code matrix shifter circularly shifts the active codes in a code matrix based on the pseudo random hop number to produce a circularly shifted code. A transmitter transmits the circularly shifted code.

System and method of uncorrelated code hopping in a communications system

Cable modem with voice processing capability

A timing recovery system and method for accelerated clock synchronization of remotely distributed electronic devices is provided. The system includes a phase locked loop, a linear estimator and control logic. The method includes sampling a clock signal received from an electronic device, applying a linear estimation technique to estimate the frequency and phase of the received signal and providing those estimates to a phase locked loop to accelerate the phase locked loop acquisition rate and secure signal lock quickly.

System and method for accelerated clock synchronization of remotely distributed electronic devices

A system and method are used to provide uncorrelated code hopping in a communications system. A multi-bit linear shift register receives data and clocks the data fifteen times. A word assembler receives the shifted data and outputs a fifteen bit word. A mixer mixes the fifteen bit word with an numerical value of active codes to generate a mixed signal. A divider divides the mixed signal to produce a divided signal. A truncator truncates the divided signal to its seven most significant bits to produce a pseudo random hop number. A code matrix shifter circularly shifts the active codes in a code matrix based on the pseudo random hop number to produce a circularly shifted code. A transmitter transmits the circularly shifted code matrix.

A communications management system introduces a low bandwidth phase locked loop (LoBW-PLL) working in tandem with a high bandwidth phase locked loop (HiBW-PLL). The LoBW-PLL only needs to follow the average frequency of the transported clock and not all of the excursions made by the master clock. During periods of downstream outage, the LoBW-PLL opens its loop and free wheels such that disturbances caused by a reacquisition do not impact the concept of time for the LoBW-PLL. After reacquisition, the LoBW-PLL and HiBW-PLL are compared to determine if a timing error has occurred. If a timing error is detected, the magnitude of the timing error is measured upon completion of the reacquisition cycle, and this measurement is used to correct the timing error.

Dual-PLL signaling for maintaining synchronization in a communications system

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Lawrenceville, GA, United States of America

Kevin Lee Miller