System and method for improving spectral efficiency and profiling of crosstalk noise in synchronized multi user multi-carrier communications
Granted: November 18, 2014
Patent Number:
8891638
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…
Systems and methods for positioning and messaging of reserved tones for peak-to-average ratio (PAR) reduction in DSL systems
Granted: November 11, 2014
Patent Number:
8885736
Systems and methods for reducing the peak-to-average ratio (PAR) at the transmitter can reduce the dynamic range required in various analog components. PAR can be reduced by applying a time-domain compensation signal which reduces the magnitude of peaks in the time-domain signal prior to transmission where the time-domain compensation signals use tones that are reserved for the purpose of reducing the PAR. The reservation of these reserved tones for PAR can be implemented by altering the…
Vectored DSL crosstalk cancellation
Granted: October 7, 2014
Patent Number:
8854941
A vector DSL system includes a plurality of modems, which may be multi-port devices. Unprocessed user data is extracted from the modems and passed through a private vectoring data routing apparatus to one or more vectoring modules, such as vectoring cards. Each vectoring module includes one or more vector processors that include processing units configured to process the unprocessed user data on the basis of all modems' data for a given DSL tone grouping. Processing of the unprocessed…
DSL alien noise reduction
Granted: September 30, 2014
Patent Number:
8848504
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).
Systems and methods for signaling for vectoring of DSL systems
Granted: August 26, 2014
Patent Number:
8817907
The measurement of far-end crosstalk (FEXT) in a Digital Subscriber Line communications is instrumental in the ability of using a multiple input multiple output (MIMO) pre-coder to cancel FEXT. A reliable robust back channel for transmission of error is instrumental to provide error samples for the proper operation of a MIMO pre-coder. Bins can be dedicated to insure bandwidth from the customer premises equipment (CPE) to the central office (CO). By increasing the margin used in the…
UPBO for vectored DSL
Granted: August 26, 2014
Patent Number:
8817857
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.
Method and apparatus for reducing switchover latency in IPTV systems
Granted: August 5, 2014
Patent Number:
8797872
A distribution node among a network of distribution nodes for packet based distribution of voice, video and data packets including multicast packet based distribution of video channels from at least one video server distribution node to a plurality of client distribution nodes selectively consuming the video channels is disclosed. The distribution node comprises a responsive to selection of a new video channel to identify a sub-set of packets within a set of packets of the new video…
Systems and methods for transporting time-of-day information in a communication system
Granted: July 8, 2014
Patent Number:
8775849
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…
Method and apparatus for crosstalk cancellation during SELT testing
Granted: July 1, 2014
Patent Number:
8767521
A system for performing a single ended line test (SELT) of a selected subscriber line within a bundle of in-service subscriber lines each supporting frequency division multiplexed multi-tone modulated XDSL communications. The system comprises: a crosstalk cancellation module and a SELT module. The crosstalk cancellation module is coupled to the subscriber lines and configured to cancel crosstalk between the selected subscriber line under test and the in-service subscriber lines. The SELT…
Systems and methods for frequency domain realization of non-integer fractionally spaced time domain equalization
Granted: July 1, 2014
Patent Number:
8767812
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…
Gateway device for performing communication with various devices in home networks and wide area networks
Granted: June 17, 2014
Patent Number:
8755394
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…
Method and apparatus for networked modems
Granted: April 29, 2014
Patent Number:
8711741
Networked modems configurable to establish a communication system on a wired communication medium. Each modem includes: a network module, transmit and receive path modules and a frequency domain echo canceller. The network module is configured to communicate with network modules of remaining ones of the at least three modems to allocate bandwidth of the shared communications medium for at least two discrete point-to-point communication links between corresponding pairs of the at least…
Method and apparatus for clock recovery in XDSL transceivers
Granted: April 22, 2014
Patent Number:
8705676
A multi-tone transceiver including: a transform component, a tone selector, an error detector, an aggregator and an oscillator. The transform component transforms received communications from the time domain to the frequency domain. The tone selector selects a sub-set of the received tones which exhibit an elevated signal-to-noise ratio (SNR) as a clock recovery tone set (CRTS) and drops and add tones to the CRTS as required by changes in the SNR of the individual tones. The error…
Systems and methods for performing line imbalance measurement and mitigation based on a common mode sensor
Granted: April 1, 2014
Patent Number:
8687770
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.
Reduced memory vectored DSL
Granted: April 1, 2014
Patent Number:
8687497
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. An upstream-end device such as a DSLAM communicates with a plurality of downstream-end devices such as CPE modems. 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…
Systems and methods for retransmission return channel error detection
Granted: March 18, 2014
Patent Number:
8677226
A method implemented in a digital subscriber line (DSL) system is described for minimizing a misdetection probability at a far-end coded message receiver during transmission of a coded message. The method comprises jointly determining, at the far-end coded message receiver, a P matrix and a modulation scheme. The method further comprises encoding a message into a coded message with a systematic linear block code, the systematic linear block code having a generator matrix [I P], where I…
Method and apparatus for a finite impulse response filter
Granted: March 11, 2014
Patent Number:
8671128
A finite impulse response filter (FIR) for processing a communication channel. The FIR comprises a delay line, a tap processor and a summer. The delay line has “N” taps to successive portions of the communication channel. The delay line shifts the successive portions of the communication channel once in each symbol processing interval. The tap processor subjects each of the “N” taps to a first scaling utilizing first scaling coefficients associated with filtering the current…
Method and apparatus for optimizing dynamic range in DMT modems
Granted: February 18, 2014
Patent Number:
8654866
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…
Systems and methods for mitigating self-induced far-end crosstalk
Granted: February 4, 2014
Patent Number:
8644127
Systems and methods for partial self-FEXT (far-end crosstalk) are described. One method, among others, comprises determining one or more instantaneous characteristics of an input signal, wherein the one or more instantaneous characteristics comprise one or more of amplitude of the input signal and an energy level of the input signal. The method further comprises selecting one or more disturbers to cancel according to the one or more instantaneous characteristics, wherein selecting one or…
Alien interference removal in vectored DSL
Granted: December 31, 2013
Patent Number:
8619843
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…
