Ikanos Communications Patent Applications


Granted: July 31, 2014
Application Number: 20140211936
A reduced-memory vectored DSL system includes methods and apparatus for reducing the bandwidth and memory storage demands on a vectored DSL system in which FEXT data is transmitted and stored. When test signal data, such as training and/or tracking data, is sent to determine FEXT characteristics of the DSL system, error signals are available for all or substantially all of the upstream and/or downstream frequency band DSL tones used in the system. Dividing a frequency band into…


Granted: April 24, 2014
Application Number: 20140112380
A vectored DSL system reduces or eliminates correlated alien interference in active DSL lines in the vectored system by collecting pseudo signals from inactive lines that do not carry upstream DSL transmissions and/or from common-mode voltage signals from active lines. The collected pseudo signals contain in-domain interference, such as FEXT interference from the active DSL lines in the vectored system, and correlated alien interference. After removing the in-domain interference from the…


Granted: February 27, 2014
Application Number: 20140056396
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…


Granted: July 4, 2013
Application Number: 20130170628
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.

Method and Apparatus for DSL Back-Channel Communication

Granted: June 13, 2013
Application Number: 20130148796
DSL backchannel data and/or information is transported upstream in a vectored, bonded line DSL system. Backchannel data (e.g., error samples or the like from downstream-end DSL equipment) is encapsulated/packetized using Layer 2 encapsulation. Upstream user data is packetized into Ethernet packets or the like. The backchannel data and upstream user data are combined and the combined data transmitted to an upstream-end DSL apparatus, such as an access node. The combined data are separated…

Method and Apparatus for Optimizing Dynamic Range in DMT Modems

Granted: April 18, 2013
Application Number: 20130094555
A digital subscriber line XDSL communication system for optimizing dynamic range in digital multi-tone modulated (DMT) modems. The system comprises a digital subscriber line access multiplexer (DSLAM) and at least one modem. The DSLAM distributes a near end crosstalk (NEXT) model of anticipated disturbance from neighboring disturber subscriber lines. The at least one modem has a transmit path and a receive path. The at least one modem couples to the DSLAM and is responsive to the…

System and Method for Partitioning DSL Vector Cancellation

Granted: February 28, 2013
Application Number: 20130051488
A DSL system performs crosstalk cancellation using a plurality of vectoring cancellation chips that are partitioned into two or more groups based on DSL victim lines or DSL disturber lines or DSL tones. Embodiments of the invention include both single-criteria and double-criteria partitioning methods. In double-criteria embodiments, the vectoring cancellation VCE chips are first partitioned into two or more victim DSL line groups and then in each group the VCE chips are further…

Systems and Methods for G.Vector Initialization

Granted: November 1, 2012
Application Number: 20120275591
Methods, apparatuses (e.g., DSL system hardware, DSL systems, vectoring control entities), techniques, systems, etc. are used for initializing one or more DSL lines joining a vectored DSL line group operating in Showtime. A super-periodic orthogonal pilot sequence from a set of super-periodic orthogonal pilot sequences is assigned to each joining DSL line, wherein each such super-periodic orthogonal pilot sequence in the set has length L and is orthogonal to other sequences in the set…

Method and Apparatus for Caching in a Networked Environment

Granted: October 25, 2012
Application Number: 20120271904
In general, methods and apparatus according to the invention mitigate these and other issues by implementing caching techniques described herein. So when one device in a home network downloads and plays a particular content (e.g., a video, song) from a given site, the content is cached within the network such that the same content is available to be re-played on another device without re-downloading the same content from the Internet.

Method and Apparatus for Data Transmission in Home Networks

Granted: September 20, 2012
Application Number: 20120236874
A multi-tone modem with components forming a transmit path and a receive path configured to couple to a wired communication medium for at least intermittent communication of frequency division multiplexed multi-tone modulated communication channels thereon. A Fourier transform component transforms received communication channels between a time domain and a frequency domain and vice-versa. Selected components on the receive path determine alignments between the received multiplexed…

Method and Apparatus for Peak-to-Average Ratio Reduction

Granted: July 12, 2012
Application Number: 20120177148
Peak-to-average ratio reduction is achieved by detecting peaks in an original analog signal that exceed a given threshold. Segments of the original analog signal containing such peaks are treated (e.g., by attenuation) and a composite analog signal is assembled that includes treated and untreated segments of the original analog signal. The composite analog signal is processed to perform analog-to-digital conversion to generate a composite digital signal. Segments of the composite digital…


Granted: April 19, 2012
Application Number: 20120093241
Alien noise is removed from one or more receptor DSL lines after self-FEXT has been eliminated or reduced. Information about the alien noise in the form of slicer errors can be obtained from one or more donor DSL lines that may or may not be in the same domain (e.g., a vectored DSL system).


Granted: February 2, 2012
Application Number: 20120027060
Residual FEXT resulting from intended and/or inherent partial cancellation of crosstalk in vectored DSL systems impairs upstream power back-off (UPBO) as traditionally implemented. By considering and taking into account the effects of residual crosstalk on vectored DSL system performance and operation, improved data rates and/or other vectored DSL system performance are realized through the use of UPBO parameters generated for a given residual FEXT environment.


Granted: January 26, 2012
Application Number: 20120020418
The memory storage, transmission and processing demands of a vectored DSL system are reduced by sampling a subset of DSL tones in the DSL tone range used in the vectored system. This data is smoothed (denoised) to further reduce the data's size, sacrificing some fidelity or precision as a result. Finally, lossless entropy coding or the like is performed to encode the FEXT cancellation data for storage and use. The resulting data is less likely to cause transmission bottlenecks in the…

Systems and Methods for Transporting Time-of-Day Information in a Communication System

Granted: December 1, 2011
Application Number: 20110296226
Systems and methods for synchronizing a clock at a customer premises equipment (CPE) location with a master clock at a central office (CO) location are described. One embodiment is a method that comprises receiving, by a time-of-day transmission convergence (ToD-TC) module in the CPE, ToD information relating to the master clock. Based on the received information, time stamps are applied to reference data samples. The method further comprises transporting the ToD information by…


Granted: November 10, 2011
Application Number: 20110274147
Disclosed are various embodiments for performing retransmission with on-line reconfiguration. A data stream is encoded into first frames according to a framing configuration. A request is obtained for an on-line reconfiguration of the framing configuration from a receiver. The encoding of the data stream into the first frames is suspended in response to the request. One or more first frames are retransmitted to the receiver during a retransmission time period that commences relative to…

Gateway Device

Granted: November 10, 2011
Application Number: 20110277001
Disclosed are various embodiments for a gateway device that can execute applications which can communicate with various devices in one or more home networks as well as one or more wide area networks. The gateway device can possess capabilities to communicate over various types of proprietary and/or standardized networks. Additionally, the gateway device can be equipped with the ability to communicate with home devices that are directly coupled to the gateway device. The gateway device…

Systems and Methods for Performing Line Imbalance Measurement and Mitigation Based on a Common Mode Sensor

Granted: November 3, 2011
Application Number: 20110268258
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.

Cognitive and Universal Impulse Noise Protection

Granted: October 27, 2011
Application Number: 20110264978
Impulse noise from nearby or intense electrical sources can disrupt communications over digital subscriber lines. There are many methods to deal with errors produced by impulse noise sources. Forward error correction (FEC) codes such as Reed Solomon coding along with scrambling and interleaving are used to correct small errors. However, for larger errors, retransmission is favored. Retransmission can be applied at the Discrete Multi-tone symbol level thus eliminating the need to insert…


Granted: October 20, 2011
Application Number: 20110255586
Various systems and methods are described for performing fractionally spaced time domain equalization (TEQ). One embodiment is a method implemented in a communication system for training a fractionally spaced time domain equalizer (TEQ). The method comprises performing an initialization phase, averaging a received signal in the system to reduce effects of noise in a channel, determining a channel estimate, and aligning an ideal reference signal with the received signal. The method…