Systems and methods for monitoring impulse noise
Granted: July 12, 2011
Patent Number:
7978756
Systems and methods for monitoring impulse noise are described. At least one embodiment is a method, which comprises detecting whether impulse noise is present and in response to detecting the presence of impulse noise, performing time domain analysis to determine whether one or more impulse noise sources are present based on minimum interarrival time and maximum impulse length. The method further includes performing frequency domain analysis to estimate frequencies associated with the…
Systems and methods for transmit-only peak-to-average ratio reduction in the oversampled regime using reserved tones
Granted: July 5, 2011
Patent Number:
7974181
Systems and methods for reducing the peak-to-average power 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 in the oversampled regime, using tones reserved for PAR reduction. A set of vectors corresponding to PAR tones is generated by processing out-of-phase symbols for each PAR tone to form a span matrix. The span matrix is used to find a best fit of a desired target signal…
Real-time formation of optimal power spectral density masks
Granted: July 5, 2011
Patent Number:
7974583
A technique for real-time formation of optimal power spectral density masks is disclosed. In one particular exemplary embodiment, the technique may be realized as a method for real-time formation of optimal power spectral density masks. The method may comprise sensing line conditions in a communication medium, wherein the communication medium is capable of carrying signals in a plurality of tones. The method may also comprise determining, in real-time, one or more power spectral density…
Systems and methods for MIMO precoding in an xDSL system
Granted: June 7, 2011
Patent Number:
7957477
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…
Systems and methods for deriving parameters for impulse noise detectors
Granted: May 31, 2011
Patent Number:
7953143
A system is described that comprises a frequency domain impulse noise detector configured to monitor received discrete multi-tone (DMT) symbols for impulse noise, a Reed Solomon (RS) decoder with erasure and erasure correction capability for performing error correction on received DMT symbols, and an optimization module configured to adjust parameters associated with the impulse noise detector, the optimization module configured to adjust values for ?pivot, ?c, and a ratio (m/M), wherein…
Method and apparatus for an amplifier
Granted: May 17, 2011
Patent Number:
7944301
An amplifier including complementary push and pull components, a bias component and a quiescent current balancer. The complementary push and pull components are serially coupled to one another between an electrical source and sink to generate an output signal at a common output terminal responsive to the input signal source. The bias component is coupled between the input signal source and the complementary push-pull components to bias the input signal to the push component and the input…
Method and apparatus for managing XDSL pseudo links
Granted: May 3, 2011
Patent Number:
7936679
A transceiver having shared and discrete components forming a transmit path and a receive path configured to couple to a subscriber line for establishing a communication channel with a remote transceiver. The transceiver comprises a pseudo link manager coupled between the transmit and receive path components to manage pseudo links on the subscriber line prior to entry into a session with the remote transceiver. The pseudo link manager includes: a line monitor and a disruptor. The line…
Back channel communication
Granted: April 12, 2011
Patent Number:
7925935
Included are embodiments for back channel communication. At least one embodiment of a method includes receiving data at customer premises equipment and determining at least one error in the received data. Some embodiments include formatting the determined error for communication to a central office and sending the formatted error to the central office via a back channel.
Systems and methods for resolving signal-to-noise ratio margin difference in dual latency discrete multi-tone-based xDSL systems under colored noise conditions
Granted: March 15, 2011
Patent Number:
7907658
Systems and methods for resolving signal-to-noise ratio margin difference n dual latency discrete multi-tone (DMT)-based xDSL systems under colored noise conditions. Rather than assuming a constant power spectral density (PSD) for noise over fast and interleaved data paths of a dual latency system, band edges vulnerable to colored noise are determined and data on the fast data path is allocated away from these band edges. Also, receive windowing may be used to further enhance…
Method and apparatus for adaptive hybrid termination in a multi-carrier communication system
Granted: February 1, 2011
Patent Number:
7881458
An xDSL modem having an adaptive hybrid termination impedance. The modem has a transformer with two cores, one connected to the modem's receiver and the other connected to the modem's transmitter. The two cores share an adjustable termination impedance. The modem determines which impedance setting to use, based on one or more measurements of channel loss, local echo power and received power from the far end transmitter, and the like.
Method and apparatus for differentiated communication channel robustness in a multi-tone transceiver
Granted: February 1, 2011
Patent Number:
7881362
A multi-tone transceiver including: a channel controller and a plurality of components forming a transmit path and a receive path. The channel controller configured to determine bit-loading for each successive symbol or tone set based on a 1st noise margin target for a first subset of tones in each tone set dedicated to transport of a robust communications channel (RCC) and based on a 2nd noise margin target less than the 1st noise margin target for remaining tones in each tone set…
Systems and methods for mitigating the effects of upstream far-end cross talk
Granted: November 16, 2010
Patent Number:
7835368
A method is described for reducing self-induced far end crosstalk (self-FEXT) in a multiple input multiple output (MIMO) digital subscriber line (xDSL) system. An initial value for an off-diagonal multiple input multiple output canceller (ODMC) is derived while the ODMC is inactive and while in data mode. The method includes activating the initial ODMC and converging towards an steady-state value for the ODMC by performing an adaptive algorithm to maximize the Shannon's capacity of the…
Multiplexing/demultiplexing on a shared interface
Granted: November 16, 2010
Patent Number:
7835405
An embodiment of an interface system including, among others, an aggregation device comprising a plurality of ports, a first device comprising a plurality of ports, and one or more links that link the entire plurality of ports of the aggregation device and first device, the one or more links fewer in quantity than the entire plurality of ports.
Method and apparatus for adaptive iterative decision feedback control coding in modems
Granted: October 26, 2010
Patent Number:
7822124
A modem employing feedback control coding to dynamically control signal-to-noise ratios and to identify errored codewords for retransmission. The receive path components of the modem include a signal-to-noise estimator, a feedback controller and a dynamic demapper. The signal-to-noise estimator repeatedly determines a difference between a target signal-to-noise ratio (SNR) and actual SNR in communications received from an opposing modem. A feedback controller responds to each…
Systems and methods for improved bit loading for discrete multi-tone modulated multiple latency applications
Granted: October 12, 2010
Patent Number:
7813434
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…
Systems and methods for minimum-power leakage windowing for VDSL using least square technique
Granted: September 14, 2010
Patent Number:
7796685
Systems and method for minimum power leakage windowing for VDSL using least squares technique are provided. A coefficient vector is defined for the first N samples. The window is then defined in terms of this coefficient vector. The leakage power of the Kth tone is defined in terms of the window. A least squares minimization is performed on the leakage power to determine the optimal value of x. The window is implemented using this value of x, thereby reducing the power leakage in the…
Method and system for reducing interferences due to handshake tones
Granted: July 27, 2010
Patent Number:
7764752
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…
Compact packet switching node storage architecture employing double data rate synchronous dynamic RAM
Granted: July 20, 2010
Patent Number:
7760726
A two-chip/single-die switch architecture and a method for accessing a DDR SDRAM memory store in a switching environment are presented. The two-chip/single-die architecture includes an internal memory storage block on the single-die, an external memory storage interface to a Double Data Rate Synchronous Dynamic Random Access Memory (DDR SDRAM), an external memory manager, and a packet data transfer engine effecting packet data transfers between an internal memory store and the external…
Enhanced smart DSL systems for LDSL
Granted: June 15, 2010
Patent Number:
7738541
A “Smart DSL System” for addressing the performance objectives of LDSL and examples of smart systems for LDSL are disclosed. In accordance with embodiments of the invention, there is disclosed a method for implementing smart DSL for LDSL systems. Embodiments of the method include presenting a number of spectral masks that are available on the LDSL system, and selecting from the number of spectral masks an upstream mask and a downstream mask wherein the upstream mask and the…
Method and apparatus for an amplifier
Granted: June 1, 2010
Patent Number:
7728670
An amplifier including complementary push and pull components, a bias component and a quiescent current balancer. The complementary push and pull components are serially coupled to one another between an electrical source and sink to generate an output signal at a common output terminal responsive to the input signal source. The bias component is coupled between the input signal source and the complementary push-pull components to bias the input signal to the push component and the input…
