Broadcom Corporation

Altocom, Inc.

Qualcomm Incorporated

Haixiang Liang

Mark Gonikberg

Zarko Draganic

Gregory H Efland

Arthur J Carlson

Yuanjie Chen

Ilya Stomakhin

James Simon Cho

Alan G Corry

Yongbing Wan

Kevin H Peterson

Purushotham Kamath

Larry C Yamano

Prem Kumar

Matthew Daniel Smith

Yury Gonikberg

Gong-San Yu

Jeff Z Guan

Lin Yin

Nino Pietro Ferrario

George A Papanicolaou

Meera Prahlad

A system and method for analyzing the real-time performance of a communication device. An aspect of the present invention records information input to the communication device during real-time operation of the communication device. A playback device or module may execute a model of the communication device in a non-real-time environment according to the recorded real-time input information. System execution in the non-real-time playback environment may, therefore, be equivalent to the original operation of the communication device that occurred in real-time. Accordingly, situations that occur in real-time may be efficiently recreated in non-real-time playback. An operator may analyze the past real-time performance of the communication device using the playback device or module, the recorded real-time input information, and a debugger utility if desired, without conducting additional trials to reproduce the desired operational situation.

Operational analysis system for a communication device

Starting up and synchronizing multiple access points in a wireline communications circuit using transceivers compatible with a wireless communications protocol with an adaptive Time Division Multiple Access scheme for a multi-channel medium with colocated transceivers. Synchronization readiness is asserted and the access points wait for a synchronization start signal's assertion. Methods of operating an access point, its implementation as a chip are further disclosed. An access point assembly including the access points and a synchronization circuit are also disclosed.

Method and apparatus for synchronizing and/or starting access points for adaptive time division multiplexing on a multi-channel wireline medium with colocated transceivers

Provided is a system and method for a modem including one or more processing paths. Also included is a number of interconnected modules sequentially arrayed along the one or more paths. Each module is configured to (i) process signals passed along the paths in accordance with the sequence and (ii) implement predetermined functions to perform the processing. Further, each of the modules has a particular degree of functional programmability and the degrees of functional programmability monotonically vary in accordance with the sequence.

Asymmetric digital subscriber line modem apparatus and methods therefor

In a data communication system, a transmitter of a modem, for example, uses a single scrambler to operate in a data communication mode and in a non-data mode. During the data communication mode the scrambler is used to scramble data for communication by the transmitter. During the non-data mode, the scrambler is used to generate a non-data mode signal for communication by the scrambler. The modem may be an ADSL modem, for example, in which case the data communication mode is SHOWTIME while the non-data mode may be Q-mode.

Data scrambler generation of pseudo-random bit sequence for semi-stationary Q-mode signal

A Finite Impulse Response (FIR) filter is implemented in software on a general purpose processor in a manner which reduces the number of memory accesses as compared to conventional methods. In particular, an efficient implementation for a general purpose processor having a substantial number of registers includes inner and outer loop code which together make memory accesses and KN multiply-accumulates, where Lis the number of output vector elements computed during each pass through the outer loop and where Lis the number of taps per output vector element computed during each pass through the inner loop. The efficient implementation exploits L+2Lgeneral purpose registers. For an embodiment in which L=L=8, inner and outer loop code make memory accesses, which for filter implementations with large numbers of taps, approaches a 4&#xd7; reduction in the number of memory accesses as compared to conventional methods.

Efficient implementation of a filter

An impairment compensation sequence for use in a communication system susceptible to one or more potential impairments each periodic in an integer number of symbols includes N phases, wherein N is selected such that each potential impairment, if present, is periodic therein, and a sequence of symbols, the sequence organized to place at least one instance of each symbol from a predetermined set of symbols in each phase to allow detection of the potential impairments in each of the N phases. The potential impairments may include robbed-bit signaling and padding. Using estimates prepared based on such an impairment compensation sequence, individual phase intervals may be grouped according to similarity of apparent aggregate effect of the impairments thereon without identification of individual impairments active in the particular phases. Constellation points may then be assigned based on group characteristics corresponding to phase intervals. In an exemplary realization, constellation points are assigned for each of 6 constellation indices based on amplitude estimates characteristic of the groups with which each of 4 corresponding phase intervals are associated.

Impairment compensation sequence for communication

An impairment compensation sequence for use in a communications system susceptible to one or more potential impairments each periodic in an integer number of symbols includes N phases, wherein N is selected such that each potential impairment, if present, is periodic therein, and a sequence of symbols, the sequence organized to place at least one instance of each symbol from a predetermined set of symbols in each phase to allow detection of the potential impairments in each of the N phases. The potential impairments may include robbed-bit signaling and padding. Using estimates prepared based on such an impairment compensation sequence, individual phase intervals may be grouped according to similarity of apparent aggregate effect of the impairments thereon without identification of individual impairments active in the particular phases. Constellation points may then be assigned based on group characteristics corresponding to phase intervals. In an exemplary realization, constellation points are assigned for each of 6 constellation indices based on amplitude estimates characteristic of the groups with which each of 4 corresponding phase intervals are associated.

Impairment sensitive selection of constellation points for communication across a channel

A method for forming a non-iterative time-domain equalizer (TEQ) and apparatus corresponding thereto. A channel response H(z) is followed by a TEQ response A(z) and a residual output B(z) is chosen so that its degree is less than a cyclic prefix. An error signal is formed so that E(z)=H(z)A(z)&#x2212;B(z). With a unit input, the error signal is set to zero and B(z)=H(z)A(z). Each signal is expressed as a polynomial, having varying degrees, and a having corresponding coefficients. Once expanded, the coefficients of similar degree can be equated on both sides of the equation. The error signal can then be determined in terms of coefficients corresponding to the TEQ and the residual signal. The coefficients of the channel response can be derived from the channel training estimates. The error signal is minimized and the result is solved for in terms of the desired TEQ coefficients.

Non-iterative time-domain equalizer

Categorization of impairments affecting a communication channel

Method and system for implementing SLICE instructions

Reliable detection of a call-waiting tone is provided by employing a correlation based technique. A modem or other device employing such a technique need not rely on carrier drop detection and is generally insensitive to other energy or noise on the line.

Apparatus, method and software for call-waiting tone detection

A technique is described for reliably determining whether a direct digital connection exists between a transmitting server modem and a receiving client modem. Such a determination is an essential part of the training procedure for modems that conform to ITU-T Recommendation V.90 but is also applicable to other data communications configurations and equipment. In some configurations in accordance with the present invention, segments of a modem training signal, LL, are used to make the determination.

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Palo Alto, CA, United States of America

Haixiang Liang