Brooktree Broadband Holding, Inc.

Globespan Technologies, Inc.

Conexant Systems, Inc.

Ikanos Communications, Inc.

Globespan Virata Corporation

Conexant, Inc.

Globespan, Inc.

At+t Corp.

Globespan Semiconductor, Inc.

Ikanos Technology Ltd.

Ehud Langberg

William H Scholtz

Patrick Duvaut

Lujing Cai

Shareq Rahman

Massimo Sorbara

Jin-Der Wang

Laurent Pierrugues

Albert Rapaport

Weimin Liu

Xy Chen

James Zhang

Ben Chan

Amitkumar Mahadevan

Richard Gut

Oliver Moreno

Faina Shmulyian

Farooq Jabbar

Jean-Jacques Werner

Daniel Amrany

Julien D Pons

Hanan Herzberg

Gi-Hong Im

Yan Wu

Feng Ouyang

Peter Kleewein

Robin Levonas

Wenye Yang

Wolfgang Kleewein, Legal Representative

Xiao Liu

Chenshu Wang

William Sholtz

Xian-Ying Chen

Shlomo Gadot

Anupama Ramalingam

Ehud Barak

Xueming Lin

A method and system are provided for preventing data loss in a VoIP system. In particular, during a VoIP call, it is determined whether incoming ringing on a POTS line causes an unacceptable level of signal loss or errors. If so, for subsequent VoIP calls, the CO handling calls to the POTS line is instructed to either answer each call with a busy signal or automatically forward calls to the POTS line to the VoIP line or other selected telephone. Calling returns to normal upon ending of the VoIP call. In this manner, incoming ringing on the POTS line does not result in call dropping or lengthy retraining processes.

Residential gateway for voice over internet protocol communications

Method and system for preventing data loss in a real-time computer system

One embodiment is a method for precoding data for transmission in a discrete multi-tone (DMT) system to cancel self-induced far end crosstalk (self-FEXT). The method comprises learning, by the system, characteristics associated with a plurality of N users within a digital subscriber line (xDSL) system to determine an initial off-diagonal multiple input multiple output (MIMO) precoder (ODMP) for a given tone frequency and converging towards an ODMP from the initial ODMP to cancel self-FEXT for the plurality of N users, wherein the ODMP is represented as a zero diagonal matrix containing only off-diagonal terms.

Systems and methods for MIMO precoding in an xDSL system

The present invention overcomes various problems by defining two upstream masks (U, U) and two downstream masks (D, D) and using a mask selectable system for the long reach digital subscriber line (LDSL), in which a unique modem feature is activated during handshake to automatically check for physical layer status in terms of spectral compatibility and, thus, automatically optimize the boosted mode with the use of the mask selectable system choose the best combination of upstream/downstream masks in any physical layer noise scenario.

System and method for selectable mask for LDSL

Systems and methods for off-diagonal MIMO precoders are described. At least one embodiment includes a method for precoding data for transmission in a discrete multi-tone (DMT) xDSL system to cancel self-induced far end crosstalk (self-FEXT) comprising: learning characteristics associated with a plurality of N users within the xDSL system to determine an initial off-diagonal multiple input multiple output (MIMO) precoder (ODMP) for a given tone frequency; and converging towards an optimum ODMP from the initial ODMP in order to cancel downstream self-FEXT for the plurality of N users, wherein the ODMP is represented as a zero diagonal matrix with only off-diagonal terms, and wherein the converging towards the optimum ODMP comprises: maximizing the channel capacity for the plurality of N users for the given tone frequency; and minimizing an increase in transmit power of the xDSL system relative to an original transmit power where a precoder is not active.

Systems and methods for performing bit loading in a dual latency data transmission system. In a computer network, such as an XDSL-based network, carrier channels are allocated between two latency paths. Error sensitive information is transmitted over a latency path employing one or more forward error correction techniques. Latency sensitive information that is relatively more tolerant of errors is transmitted over the other latency path. Rather than employing the lowest coding gain for carrier channels having the two different latency paths, the highest coding gain for each path is used by applying different target S-N-R margins for carrier channels having different latency paths.

Systems and methods for improved bit loading for discrete multi-tone modulated multiple latency applications

A method and system of the present inventions reduces both near-end crosstalk (NEXT) and far-end crosstalk (FEXT) interferences due to handshake tones into upstream and downstream neighboring services, both at the customer premises equipment (CPE) and at the central office (CO), when handshake is experienced. An embodiment of the present inventions is directed to significantly reduce the NEXT and/or FEXT interferences due to handshake tones. For example, NEXT and/or FEXT interferences due to G.994.1 handshake tones, identified as, binsandfor the Upstream channel and binsandfor the Downstream channel may be reduced. An embodiment of the present inventions provides an algorithm that may be used for both NEXT and FEXT Handshake Interferences reduction at the CO and at the CPE. In addition, the algorithm may operate in the time domain and in the frequency domain. Frequency domain algorithm offers two options, both versions taking advantage of the high correlation time of the Handshake tone signals.

Method and system for reducing interferences due to handshake tones

A technique for improving multiple-channel multi-tone transmissions is disclosed. According to one particular embodiment, a method for transmitting data over at least two bonded channels is provided, wherein each of the at least two bonded channels comprises a plurality of tones. The method may comprise: transmitting a first symbol stream over a first tone in a first bonded channel and over a second tone in a second bonded channel, wherein the first tone is bonded to the second tone, and the transmissions over the first tone and the second tone are substantially in parallel; transmitting a second symbol stream over a third tone in the first bonded channel; and transmitting a third symbol stream over a fourth tone in the second bonded channel, wherein the third tone is bonded to the fourth tone, and the transmissions of the second symbol stream and the third symbol stream are substantially in parallel.

Technique for improving multiple-channel multi-tone transmissions

The present invention is directed to implementing theoretical foundations of frequency domain methods aiming to locally decrease the impact of aggregate side lobes of a few discrete frequency tones, in the vicinity of other 'victim' frequencies. The family of frequency methods referred to makes use of one or more 'canceller tones.' The &#x201c;canceller tones&#x201d; loads are optimized to minimize the aggregate power in the neighborhood of the victim frequencies. An exemplary method for decreasing an impact of aggregate side lobes of one or more discrete frequency tones in the vicinity of one or more victim tones comprises the steps of calculating an aggregate power of one or more side lobes of one or more disturber tones within a victim bandwidth; determining at least one optimal load to minimize the aggregate power wherein the at least one optimal load comprises a linear combination of the one or more disturber tones; and applying the at least one optimal load to one or more canceller tones for minimizing the impact of the one or more side lobes of the one or more disturber tones.

Method and system for mitigating Fourier transform side lobes

Disclosed herein are various techniques for multilevel channel coding. For a given binary word comprising a plurality of bits, the least-significant bit may be encoded by a boosted coding technique, such as turbo channel coding or low density parity check (LDPC) channel coding. A subset of the remaining bits of the binary word may be encoded using trellis coded modulation (TCM) coding. The results of the boosted channel coding and the TCM coding may be mapped to one or more symbols. The one or more symbols then may be transmitted to a receiver using transmission techniques well known to those skilled in the art. The present invention finds particular benefit in digital subscriber line (DSL)-based systems in accord with the ITU G.922.1 Recommendation and similar standards.

Multilevel channel coding in ADSL

Various embodiments for addressing the performance objectives of LDSL and examples of smart systems for LDSL are disclosed. An evaluation of the spectral compatibility of two LDSL modes based on two different downstream masks, identified herein as LDSL Wide and Narrow, is disclosed. Spectral compatibility is evaluated in accordance with existing rules. Other embodiments may further comprise determining features of upstream transmission.

Implementation of smart DSL for LDSL systems

A system and method for multiple inputs, multiple outputs (MIMO) PSD allocation in a DSL system is disclosed. In some embodiments, the method may comprise monitoring system performance by performing a multi-ended line test (MELT), processing the MELT and allocating PSD based on at least one of system coupling power and system traffic.

MIMO dynamic PSD allocation for DSL networks

An economic low-complexity system and method for echo cancellation are disclosed. The system and method are particularly suited for multi-carrier VDSL using the U0 band. The techniques taught herein may be implemented in VDSL and VDSL2 systems and used to receive signals in three bands (e.g., U0, U1 and U2) simultaneously.

System and method of echo cancellation

Growing community of inventors

Wayside, NJ, United States of America

Ehud Langberg