Patents Assigned to CONEXANT SYSTEMS
  • Publication number: 20090325571
    Abstract: Included are embodiments for utilizing a scanning threshold. More specifically, one embodiment of a method includes entering a standby mode, wherein in the standby mode, at least one component of a communications device is shutdown, and wherein in the standby mode, at least one channel is scanned to determine potential interference and monitoring exchanged traffic with the communications device. Some embodiments include determining a relative volume of the exchanged traffic, compared to a predetermined threshold and based on the determination of the relative volume of the exchanged traffic and the predetermined threshold, entering a power save standby mode, wherein in the power save standby mode, scanning of the at least one channel is terminated.
    Type: Application
    Filed: April 28, 2008
    Publication date: December 31, 2009
    Applicant: CONEXANT SYSTEMS INC.
    Inventor: Maarten Menzo Wentink
  • Publication number: 20090315617
    Abstract: Systems and methods for providing bias currents to multiple analog circuits are disclosed. An integrated circuit comprises a calibration circuit which compares a high tolerance external component to a plurality of internal components manufactured to span the variability of the process, voltage and temperature. The best fitting internal component is communicated to bias circuits which can select an internal component from a local plurality of internal components with matching desired characteristics. In this manner, analog circuits can be locally biased with the tolerance usually associated with a high tolerance external reference component, without the necessity for a local external reference component.
    Type: Application
    Filed: June 20, 2008
    Publication date: December 24, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Ray Rosik, Weinan Gao
  • Publication number: 20090310618
    Abstract: The disclosed methods of low power communications facilitate high speed reception of data from an access point (AP) with low transmission latencies while remaining in power save mode as long as possible. The disclosed methods allow the client to remain in a power save state and involve creating a synchronous client frame exchange with the AP that is independent of a digital traffic indication map and the AP's beacon interval. Two methods to accomplish this goal are disclosed: one which involves sending PS Poll Frames; and one that includes fast CAM switching, both at a self tuning frequency.
    Type: Application
    Filed: June 13, 2008
    Publication date: December 17, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventor: Trent Carter
  • Publication number: 20090310658
    Abstract: 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 typical startup procedures in a digital subscriber line (xDSL) system. The use of the reserved tones to reduce the PAR can be implemented using a low complexity algorithm or using an adaptive technique.
    Type: Application
    Filed: June 13, 2008
    Publication date: December 17, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Rahul Garg, Patrick Duvaut, Amitkumar Mahadevan, Harish Jethanandani
  • Publication number: 20090310755
    Abstract: Systems and methods for performing loop analysis are described. Some embodiments are directed to determining loop characteristics such as loop gauge, loop termination, and straight-loop departure. One embodiment includes a method for performing loop length estimation which comprises receiving an un-calibrated echo signal for a loop under test using frequency domain reflectometry single-ended line testing (FDR-SELT), a region associated with the loop under test, and a platform type. The method comprises classifying the loop under test and outputting a loop length estimate based on the classification of the loop under test and based on one of a ripple-period approach and a template-matching approach.
    Type: Application
    Filed: June 13, 2008
    Publication date: December 17, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Vaibhav Dinesh, Kunal Raheja, Patrick Duvaut
  • Publication number: 20090257581
    Abstract: Included are embodiments for reducing alien crosstalk. At least one embodiment of a method includes receiving noise data associated with a first user signal on a first tone, receiving noise data associated with a second user signal on the first tone, and receiving at least one alien crosstalk canceller coefficient for the first user on the first tone. Some embodiments include applying the at least one alien crosstalk canceller coefficient to the second user signal to reduce alien crosstalk for the first user signal.
    Type: Application
    Filed: April 9, 2008
    Publication date: October 15, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Pravesh Biyani, Amitkumar Mahadevan, Patrick Duvaut
  • Publication number: 20090252234
    Abstract: 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 one or more impulse noise sources and based on the time domain analysis and frequency domain analysis, providing a total number of impulse noise sources and frequencies associated with the impulse noise sources. In this regard, the embodiments described herein provide dual-speed monitoring of impulse noise in the form of short-term and long-term monitoring.
    Type: Application
    Filed: April 7, 2008
    Publication date: October 8, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Hemant Samdani, Kunal Raheja, Rahul Garg, Patrick Duvaut, Amitkumar Mahadevan, Robert A. Day, Robin Levonas
  • Publication number: 20090249133
    Abstract: Systems and methods for protecting DSL systems against impulse noise are provided. Disclosed herein are example embodiments of a retransmission technique located above the gamma interface (i.e., in the network processing layer). Such a retransmission technique can be combined with standard RS coding with standard erasure-decoding & triangular interleaving at the PMS-TC layer. Example embodiments of the technique involve using the RS code to protect against REIN noise, and using ?-layer retransmission for protecting against error events not corrected by the RS code, e.g. a SHINE noise in the presence of REIN. Both techniques are used jointly in the case of combined REIN and SHINE noise.
    Type: Application
    Filed: March 26, 2009
    Publication date: October 1, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Julien D. Pons, Ravindra M. Lambi, Patrick Duvaut, Massimo Sorbara
  • Publication number: 20090232232
    Abstract: Included are embodiments of method for method for computing metrics. At least one embodiment includes searching a MIMO detection tree, the detection tree configuration being formed by a plurality of nodes and a plurality of leaves connected via a plurality of branches, the computational complexity associated with computing a node metric decreases with the node depth in the tree configuration and providing an estimate on a transmitted signal.
    Type: Application
    Filed: October 15, 2008
    Publication date: September 17, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Patrick Duvaut, Julien D. Pons
  • Publication number: 20090219979
    Abstract: The present invention overcomes various problems by defining two upstream masks (U1, U2) and two downstream masks (D1, D2) and using a mask selectable system for the long reach digital subscriber line (LDSL), in which a unique modem feature is activated during handshake to automatically check for physical layer status in terms of spectral compatibility and, thus, automatically optimize the boosted mode with the use of the mask selectable system choose the best combination of upstream/downstream masks in any physical layer noise scenario.
    Type: Application
    Filed: February 24, 2009
    Publication date: September 3, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Patrick Duvaut, Ehud Langberg
  • Publication number: 20090217334
    Abstract: A modem for use with a computer having a demodulator and a decoder, the modem comprises a hardware interface; a demodulator front-end having a first input and a first output, the first output of the demodulator front-end being configured to interface with the demodulator of the computer and to provide a demodulated front-end signal to the demodulator over the hardware interface; and a forward error correction (FEC) unit having a second input and a second output, the second input of the FEC unit being configured to interface with the demodulator of the computer and to receive a demodulated signal from the demodulator over the hardware interface, the demodulated signal being a demodulation of the demodulated front-end signal, and the second output of the FEC unit being configured to interface with the decoder of the computer and to provide an FEC signal to the decoder over the hardware interface.
    Type: Application
    Filed: February 26, 2008
    Publication date: August 27, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventor: Chi-Ping Nee
  • Publication number: 20090216489
    Abstract: Systems and methods for deriving parameters for frequency domain impulse noise detectors are described. At least one embodiment is a method for deriving a set of parameters associated with a frequency domain impulse noise detector. In accordance with such embodiments, the method comprises setting values for ?pivot and ?c, wherein ?pivot and ?c are values associated with a monotonic function of a ratio of a statistical parameter of disruptive noise to a statistical parameter of nominal noise. The method further comprises selecting a fixed ratio (m/M), wherein M is a number of monitored tones, and wherein m is a number of slicer error samples that must exceed a decision threshold for a symbol to be flagged as corrupted.
    Type: Application
    Filed: February 22, 2008
    Publication date: August 27, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Amitkumar Mahadevan, Patrick Duvaut, Julien D. Pons
  • Publication number: 20090190666
    Abstract: In one aspect, a method for encoding pictures is provided. The method is applied to each picture in a sequence of pictures, and the method comprises the steps of assigning a pre-decoder buffer removal time to the picture; selecting, for the picture, a number of bits, wherein the time-equivalent of the number of bits is no greater than a difference based on the pre-decoder buffer removal time of the picture and an initial arrival time of the picture into a pre-decoder buffer; and compressing the picture to generate the number of bits. The method may further include the step of allocating a first number of bits for compressing the picture and one or more number of bits for compressing one or more future pictures, wherein the future pictures are in the pre-decoder buffer at the pre-decoder buffer removal time of the current picture.
    Type: Application
    Filed: March 31, 2009
    Publication date: July 30, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Eric Viscito, Dzung T. Hoang
  • Publication number: 20090177938
    Abstract: 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 sequence identification into data transmission units, furthermore retransmission can also be employed to exploit the error correcting capabilities of the FEC codes. Finally, an impulse noise protection system can exploit impulse noise statistics to configure the redundancy in the FEC codes and to enable the use of blanking. Exemplary embodiments of systems described can cooperatively use impulse noise statistics to utilize retransmission, FEC and blanking to mitigate the effects of impulse noise.
    Type: Application
    Filed: January 5, 2009
    Publication date: July 9, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Julien D. Pons, Patrick Duvaut, Massimo Sorbara, Yue-Peng Zheng
  • Publication number: 20090122855
    Abstract: Systems and methods for mitigating the effects of self-FEXT within an xDSL system are described. At least one embodiment is a method for reducing self-induced far end crosstalk (self-FEXT) in a multiple input multiple output (MIMO) digital subscriber line (xDSL) system. The method comprises deriving an initial value for an off-diagonal multiple input multiple output canceller (ODMC) while the ODMC is inactive and while in data mode. The method further comprises 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 system and to reduce upstream self-FEXT. The method also comprises performing bit loading and updating a frequency domain equalizer (FEQ).
    Type: Application
    Filed: May 20, 2008
    Publication date: May 14, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Patrick Duvaut, Amitkumar Mahadevan, Pravesh Biyani, Shailendra Singh, Satyavardhan Maheshwari
  • Publication number: 20090116545
    Abstract: An adaptive frequency equalization system providing an equalizer that has programmable taps that adjusts magnitude and phase of symbol information of a received signal and that provides equalized symbol information. The system includes a hard decision circuit that selects ideal symbol values using the equalized symbol information. A frequency response circuit determines frequency response update values using the ideal symbol values and the received signal. An adjust circuit updates stored frequency response information using the frequency response update values, and also updates the programmable taps of the equalizer using the stored frequency response information.
    Type: Application
    Filed: October 6, 2008
    Publication date: May 7, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Daniel D. Shearer, III, Alex C. Yeh, Mark A. Webster, Steven D. Halford
  • Publication number: 20090089813
    Abstract: There is provided a method of redirecting an audio stream from a first audio endpoint to a second audio endpoint in a computer operating system. The method includes directing the audio stream from a client application through a first audio resource stack to the first audio endpoint; creating an audio endpoint bridge to provide a path for the audio stream from the first audio resource stack through a second audio resource stack connected to the second audio endpoint; and redirecting the audio stream to the second audio endpoint using the audio endpoint bridge. The audio endpoint bridge can be created by forming a bridging application so as to activate the second audio stack. The bridging application can be hooked into a Windows audio engine in the second audio resource stack.
    Type: Application
    Filed: May 16, 2008
    Publication date: April 2, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: James W. Wihardja, Xiaoyan Vivian Qian
  • Publication number: 20090086987
    Abstract: There is provided a method of redirecting an audio stream from a first audio endpoint to a second audio endpoint in a computer operating system. The method includes directing the audio stream from a client application through a first audio resource stack to the first audio endpoint; creating an audio endpoint bridge to provide a path for the audio stream from the first audio resource stack through a second audio resource stack connected to the second audio endpoint; and redirecting the audio stream to the second audio endpoint using the audio endpoint bridge. The audio endpoint bridge can be created by forming a bridging application so as to activate the second audio stack. The bridging application can be hooked into a Windows audio engine in the second audio resource stack. The bridge can be used to intercept an audio stream and remove noise from it. Additionally, a specific type of noise with sporadic intermittent spikes has been observed in this audio framework with certain Bluetooth headsets.
    Type: Application
    Filed: June 30, 2008
    Publication date: April 2, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: James W. Wihardja, Xiaoyan Vivian Qian, Jonathan Chien, Yair Kerner
  • Publication number: 20090059824
    Abstract: Included are embodiments for network allocation. More specifically, one embodiment of a method includes receiving, at a first communications device, without a prior RTS signal being sent, a first clear to send (CTS) signal from a second communications device, addressed to the first communications device, the CTS signal indicating a data exchange duration and sending a second CTS signal, from the first communications device, to the second communications device.
    Type: Application
    Filed: April 21, 2008
    Publication date: March 5, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventor: Maarten Menzo Wentink
  • Publication number: 20090031044
    Abstract: Disclosed is an apparatus and method for storing and searching computer node addresses in a computer network system. In one embodiment, the apparatus comprises a frame forwarding device such as a switch. The switch includes two MAC address tables including a primary MAC address table and secondary MAC address table both for storing and searching MAC addresses. The primary table stores records that contain compressed values of MAC addresses. The records are contained in storage locations that are referenced using the compressed value of the MAC address as a search index. In order to account for searching collisions that may result from different MAC addresses compressing to the same value, each record in the primary address table is linked to a chain of records in the secondary table. The records in the secondary table store the full value of the MAC address. Each chain of records in the secondary address table contains MAC addresses the present invention.
    Type: Application
    Filed: April 22, 2008
    Publication date: January 29, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Craig Barrack, James Ching-Shau Yik, Rong-Feng Chang, Eric Lin