Ikanos Communications Patent Grants

Systems and methods for G.vector initialization

Granted: February 23, 2016
Patent Number: 9270831
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 designing an improved transmit signal for use in a single ended line test (SELT)

Granted: November 10, 2015
Patent Number: 9185204
The present invention relates to methods and apparatuses of using a novel transmit signal that can be used to improve performance of various loop diagnostic features of SELT. In embodiments, a novel transmit signal uses a wide contiguous band of tones that includes frequencies in both upstream and downstream bands. In these and other embodiments of the invention, the SELT transmit signal is designed such that any crosstalk noise in adjacent lines appears as a burst of noise that falls…

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

Granted: November 10, 2015
Patent Number: 9184774
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…

Systems and methods for characterizing loops based on single-ended line testing (SELT)

Granted: November 3, 2015
Patent Number: 9178990
Systems and methods for characterizing loops based on frequency domain reflectometry single-ended line testing (FDR-SELT) are described. One embodiment includes a method for determining whether a straight-loop departure condition exists on a loop under test. First, an un-calibrated echo signal is received. A region associated with the loop under test, a platform type, and estimated the length of the loop under test are then used together with the received un-calibrated echo signal to…

Method and apparatus for detecting improper connections near a customer premises equipment

Granted: November 3, 2015
Patent Number: 9178668
Methods and apparatuses are disclosed for detecting improper connection near the end of an xDSL loop based on separately analyzing the location and levels of time domain signals associated with different transmission bands in an xDSL band plan. In one embodiment, a method is disclosed to separately convert the received test signal data to different sets of time domain data corresponding to different sets of the separate frequency bands, and then to separately analyze the different sets…

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

Granted: October 20, 2015
Patent Number: 9166651
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…

Customer premise SELT based method for detecting the presence of a micro-filter on a VDSL connection

Granted: August 4, 2015
Patent Number: 9100507
The present invention relates generally to a customer premises based method for detecting the presence of a micro-filter on a VDSL connection. According to certain aspects, the method uses SELT test signals that are transmitted from the customer premises modem and whose associated echo signals are received and analyzed by the customer premises modem. According to further aspects, specific characteristics of several different SELT signals are utilized to robustly and effectively determine…

System and method for selecting parameters for compressing coefficients for nodescale vectoring

Granted: July 21, 2015
Patent Number: 9088350
In general, the present invention relates to methods and systems for optimizing the precoder coefficient compression parameters for reducing the storage and other demands on a vectored DSL system. Embodiments of the invention can be implemented in conjunction with various existing coefficient compression techniques such as quantization of coefficients and decimation in frequencies. According to certain aspects, the compression parameters (e.g. Golomb modulus and quantization level) are…

System and method for partitioning DSL vector cancellation

Granted: June 23, 2015
Patent Number: 9065534
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…

Method and apparatus for data transmission in home networks

Granted: June 9, 2015
Patent Number: 9054931
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…

DM-CM diversity receiver for a wireline communication system

Granted: May 26, 2015
Patent Number: 9042498
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…

Systems and methods of resource allocation for cancellation of crosstalk

Granted: May 26, 2015
Patent Number: 9042211
A method implemented in a multi-user communication system is described for performing far-end crosstalk (FEXT) cancellation for each victim user. The method comprises performing dynamic programming to allocate resources according to (N?1) normalized disturber coupling values and difference rate function values associated with N total users in the system involved in partial FEXT cancellation. In accordance with some embodiments, dynamic programming comprises selecting a tone and one or…

Method and apparatus for peak-to-average ratio reduction

Granted: May 19, 2015
Patent Number: 9036730
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…

Systems and methods for retransmission with on-line reconfiguration

Granted: March 24, 2015
Patent Number: 8989239
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…

Method and apparatus for maintaining and migrating a distributed cache in a networked environment

Granted: March 3, 2015
Patent Number: 8972517
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.

System and method for canceling radio frequency interferers (RFI's) in xDSL signals

Granted: February 17, 2015
Patent Number: 8958468
A system and method for canceling noise in a received signal are provided. A signal is received at a receiver comprising a frequency domain equalizer (FEQ). A noise prediction error of the signal is determined. The FEQ is updated with the noise prediction error, wherein the act of updating mitigates the effect of noise in the signal.

Method and apparatus for a current control

Granted: February 3, 2015
Patent Number: 8947282
A current controller includes impedance elements coupled to form at least one impedance ladder circuit which exhibits a fixed impedance at an input and current divider steps each differing in a current magnitude by a multiple of three with respect to the current magnitude in an adjacent less significant step. Single pole triple throw (SPTT) switchably couple an associated step in the impedance ladder circuit to one of three outputs. Three discrete current sources or sinks are each…

Diagnostics primitives on L2/ERB normalized error samples

Granted: December 30, 2014
Patent Number: 8923487
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: December 23, 2014
Patent Number: 8917747
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…

Alien interference removal in vectored DSL

Granted: November 25, 2014
Patent Number: 8897347
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…