Ikanos Communications, Inc.

Conexant, Inc.

Globespan Virata Corporation

Brooktree Broadband Holding, Inc.

Laurent Pierrugues

Patrick Duvaut

Laurent Alloin

Arnold Muralt

Oliver Moreno

Ehud Langberg

Julien D Pons

William Edward Keasler, Jr

Amitkumar Mahadevan

William H Scholtz

Ming Gu

Peter Kleewein

Lujing Cai

Massimo Sorbara

Daniel Amrany

Pravesh Biyani

Feng Ouyang

Wolfgang Kleewein, Legal Representative

William E Keasler

William Keasler

S M Zafaruddin

Chapala Vinay Kumar

Laurent Francis Alloin

The present invention relates to methods and apparatuses for sensing noise sources in a wireline communications environment such as a customer premises environment in a DSL system. In embodiments, the invention includes an additional sensor that is connected to power mains in a DSL customer premises environment either to characterize, at their source, noises coupling into the DSL lines, and/or to mitigate their impact into the DSL lines. One objective is associated with diagnostics that help to better characterize the noise signals themselves and derive correlation of signals sensed from the power mains and their possible projection onto the DSL line. Another objective makes use of these power line sensor signals to mitigate or to eliminate power line noises that make their way onto the DSL line. Example embodiments further include and exploit signals from additional secondary sensors such as secondary common mode, differential mode and phantom mode sensors.

Method and apparatus for sensing noise signals in a wireline communications environment

The present invention generally relates to a method and apparatus for effectively detecting and characterizing noise and other events affecting a communications system such as digital subscriber lines (DSL). According to certain aspects, the invention includes a noise analysis engine that is embedded in customer premises equipment that classifies noise sources according to their specific characteristics and tracks each noise source in a dynamic manner, in such a way as to provide visibility to the changing noise environment within the customer premises and/or report this environment to a remote entity.

Method and apparatus for detecting and analyzing noise and other events affecting a communication system

In accordance with one embodiment, a method is implemented in a vectored system for improving a signal-to-noise ratio (SNR) of a far end transmitted signal on a victim line in the system. The method comprises mitigating, by the vectored system, self-induced far-end crosstalk (self-FEXT) on the victim line based on self-FEXT mitigation coefficients and receiving, by a second sensor, information relating to at least one of: self-FEXT of the vectored system, external noise, and the far end transmitted signal. The method further comprises learning, at the second sensor, coefficients relating to self-FEXT coupling into the second sensor and removing self-FEXT from the second sensor based on the learned coefficients. Upon removal of self-FEXT from the second sensor, a linear combiner configured to combine information relating to the victim line and the second line is learned.

Systems and methods for implementing a multi-sensor receiver in a DSM3 environment

In general, the present invention provides methods and apparatuses for exploiting the extra degree of freedom provided by the sensing of the CM signal along with the DM signal at the receiver end of a wireline communication system. According to certain aspects, this extra degree of freedom can be used to cancel alien noises at the receiver in both upstream downstream directions. According to further aspects, a CM channel can be potentially used to exploit the diversity created in the CM channel along with the regular DM channel. This acts as the motivation for employing a diversity receiver scheme at the receiver, especially in downstream communications received at a Customer Premises.

DM-CM diversity receiver for a wireline communication system

Derivations of new PHY layer diagnostics primitives are based on the normalized error samples collected through G.993.5. The processing uses the ERB and L2 Ethernet packet encapsulation of these ERB data in order to abstract the processing from the PHY layer device dependency, as well as to allow a local and remote processing of the primitives for diagnostics purposes.

Diagnostics primitives on L2/ERB normalized error samples

A system, method, and a computer readable medium having instructions thereupon for synchronized multi-user multi-carrier communications are provided. For example, a synchronized multi-user multi-carrier communication system includes a transmitter, a receiver communicatively coupled to the transmitter via a plurality of communication channels associated with multiple users, and a computing device, coupled to at least one of the transmitter and the receiver, comprising a memory device in communication with one or more processors. The one or more processors are configured to obtain noise samples for the plurality of communication channels, determine a coupling between carriers on the plurality of communication channels, determine a noise model for a carrier based upon the noise samples and the determined coupling, and store the noise model in the memory device.

System and method for improving spectral efficiency and profiling of crosstalk noise in synchronized multi user multi-carrier communications

One embodiment is a method for performing 2-wire line imbalance measurements. The method comprises receiving a probe signal and based on the probe signal, determining one of more of: an estimated transverse conversion loss (TCL) coupling transfer function and an estimated transverse conversion transfer loss (TCTL) coupling transfer function.

Systems and methods for performing line imbalance measurement and mitigation based on a common mode sensor

In accordance with one embodiment, a method is implemented in a vectored system for improving a signal-to-noise ratio (SNR) of a far end transmitted signal on a victim line in the system. The method comprises mitigating, by the vectored system, self-induced far-end crosstalk (self-FEXT) on the victim line based on self-FEXT mitigation coefficients and receiving, by a second sensor, information relating to at least one of: self-FEXT of the vectored system, external noise, and the far end transmitted signal. The method further comprises learning, at the second sensor, coefficients relating to self-FEXT coupling into the second sensor and removing self-FEXT from the second sensor based on the learned coefficients. Upon removal of self-FEXT from the second sensor, a linear combiner configured to combine information relating to the victim line and the second line is learned. The method further comprises applying the learned linear combiner and readjusting the self-FEXT mitigation coefficients to remove any residual self-FEXT on the victim line after application of the learned linear combiner.

A system and method for encoding information is disclosed. In one embodiment, information is encoded using a high protection code for the least significant bit and a low protection code for the next three most significant bits. The remaining bits are uncoded. The high protection code may be a turbo code and the low protection code may be a trellis coded modulation code. In this embodiment, the collection of bits is then mapped according to a diagonally shifted QAM constellation technique.

Hierarchical trellis coded modulation

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

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 method and system for reducing the power to average ratio (PAR) at the transmitter and after the up sampling and interpolation filter. In the time domain, Fractional Local Peak Detection and Mitigation (FLPDM) locally (i.e. in the neighborhood where the high peak occur) detects the high peaks at a sampling rate of T/K and combines an optimal binary and a PAR-lowering sequence at the scale of one extended symbol for multi-carrier modulation and at the scale M of symbols for single-carrier modulation. Since the technique acts locally, FLPDM does not require peaks search and processing at the scale of many time samples, does not require iterative Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) processing and it assures tunable millions of instruction per second (MIPS) performance.

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Fort Lee, NJ, United States of America

Laurent Pierrugues