Patents Assigned to Conexant Systems, Inc.
  • 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
  • Patent number: 7555052
    Abstract: Method and System for evaluating a turbo-coding scheme suitable for VDSL2 systems. The scheme is a Turbo-Trellis Coded Modulation TTCM that makes use of a Parallel Concatenated Convolutional Code (PCCC) including an inner Latin square/rectangular matrix of Random sequence pattern Interleaver (LRI) of approximately 2044 bits. In the presence of the outer Reed Solomon Code but without an outer interleaver (fast mode), the method and system provides 7.1 dB of average net coding gain, i.e., 2.6 dB of coding gain improvement relative to the standard 16 states 4-dimensional (4-D) trellis code used in current ADSL2 systems. The substantial coding gain achieved through the method and system, leads to an increase in the VDSL2 rate by 38% at 6 kft against local exchange carriers, such as ILEC (SBC) conditions with approximately 1.5 ms of latency. By encoding only two bits per tone (i.e., 1 bit per dimension), the turbo code implementation complexity is kept reasonable.
    Type: Grant
    Filed: October 13, 2005
    Date of Patent: June 30, 2009
    Assignee: Conexant Systems, Inc.
    Inventors: Julien Pons, Patrick Duvaut
  • Patent number: 7535606
    Abstract: A method of directly obtaining a Y value for a luminance/chrominance representation of a scanline of a color scanned image produced by a color contact image sensor device having a linear sensor array to collect reflected light, wherein said contact image sensor device comprises red, green and blue light sources and wherein an optimal on time for each of the light sources is calibrated, the method comprising the step of illuminating the scanline during a single pulse independently with the red, the green and the blue light sources and allowing the linear sensor array to accumulate the reflected light from all of the light sources.
    Type: Grant
    Filed: January 10, 2005
    Date of Patent: May 19, 2009
    Assignee: Conexant Systems, Inc.
    Inventors: Derek T. Walton, Brendan P. Mullaly
  • 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
  • Patent number: 7532670
    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: Grant
    Filed: September 5, 2003
    Date of Patent: May 12, 2009
    Assignee: Conexant Systems, Inc.
    Inventors: Eric Viscito, Dzung T. Hoang
  • 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: 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: 20090086733
    Abstract: 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 DDR SDRAM memory. The packet data transfer engine operates as an adaptation layer addressing issues related to employing appropriate: addressing schemes, granule sizes, memory transfer burst sizes, access timing, etc. The packet data transfer engine includes a minimal number of dual mode operational blocks such as: a queue manager, and adaptation receive and transmit blocks.
    Type: Application
    Filed: December 4, 2008
    Publication date: April 2, 2009
    Applicant: Conexant Systems, Inc.
    Inventors: Craig Barrack, Yeong Wang, Rong-Feng Chang
  • 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: 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
  • Patent number: 7489693
    Abstract: Automatic detection of the virtual circuit setting and encapsulation type of a DSL line. A DSL modem determines the correct virtual path identifier (VPI) and virtual channel identifier (VCI) by sending OAM loopback requests to different VPI/VCI pairs until a valid loopback reply is received. PPPoA encapsulation is detected when a valid reply is received to a PPP LCP configuration request or echo request. PPPoE encapsulation is detected when a valid reply is received to a PPP LCP termination request or a PPPoE discovery offer (a PADO packet) is received in response to a PPPoE discovery initiation request (a PADI packet).
    Type: Grant
    Filed: September 18, 2002
    Date of Patent: February 10, 2009
    Assignee: Conexant Systems, Inc.
    Inventor: Haibo Xu
  • Patent number: 7486688
    Abstract: 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 DDR SDRAM memory. The packet data transfer engine operates as an adaptation layer addressing issues related to employing appropriate: addressing schemes, granule sizes, memory transfer burst sizes, access timing, etc. The packet data transfer engine includes a minimal number of dual mode operational blocks such as: a queue manager, and adaptation receive and transmit blocks.
    Type: Grant
    Filed: March 29, 2004
    Date of Patent: February 3, 2009
    Assignee: Conexant Systems, Inc.
    Inventors: Craig Barrack, Yeong Wang, Rong-Feng Chang
  • 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
  • Patent number: 7484070
    Abstract: A memory of allocating memory for use by a subfunction of a computer chip, wherein the subfunction uses contiguous memory regions, the method comprising the steps of (a) creating a placeholder for contiguous memory buffers used by the subfunction of the chip by reserving a region of memory subsystem space, wherein the region does not need to be backed by true physical storage and the size is at least as large as the contiguous memory buffer required by the subfunction, (b) allocating pages of remaining memory in the memory subsystem to satisfy the amount of memory required by the subfunction, wherein the allocated pages do not necessarily result in a contiguous memory region, (c) remapping the allocated pages of step b into a contiguous region of the placeholder created in step a and (d) disabling the remapping after the subfunction is completed to free the memory in the placeholder.
    Type: Grant
    Filed: January 10, 2005
    Date of Patent: January 27, 2009
    Assignee: Conexant Systems, Inc.
    Inventors: Derek T. Walton, Carl M. Mikkelsen
  • Publication number: 20090010191
    Abstract: Stations in standby mode periodically wake up to check for buffered data at the access points. Traditionally, the information is available by checking the periodic beacon frame for a traffic indication map (TIM). Unfortunately, the length of beacons has steadily increased with the progression of the various wireless standards requiring stations to wake up for longer periods to merely check for buffered data. Several approaches are disclosed which address this shortcoming, including the broadcast of TIM frames, the partial reception of beacon frames and the use of an embedded TIM frame within a beacon frame.
    Type: Application
    Filed: March 12, 2008
    Publication date: January 8, 2009
    Applicant: CONEXANT SYSTEMS, INC.
    Inventor: Maarten Menzo Wentink
  • Patent number: 7474357
    Abstract: Provided are decoding methods and decoders for separating luminance and chrominance components of a video signal. In one aspect, a reference subcarrier of a first line of the video signal is used for subsequent lines by applying an appropriate rotation to the reference subcarrier of the first line for each subsequent line. In another aspect, comb filtering is adaptively controlled based on determining whether 90 or 180 degrees relationship is maintained from line to line. In a further aspect, both complimentary and non-complimentary comb filtering are implemented. In yet another aspect, SECAM bell filtering is achieved by rotating the video signal to obtain a baseband signal, low-pass filtering and modulating the baseband signal, and subtracting the modulated low-pass filtered baseband signal from the video signal to notch the chroma component from the luma component.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: January 6, 2009
    Assignee: Conexant Systems, Inc.
    Inventors: Peter M. Murdock, John E. Welch
  • Publication number: 20080313481
    Abstract: A system and method for wireless waking computing devices over a computer network is provided. A signal is broadcast over the network that includes one or more device specific wake-up data sequences. Each device specific wake-up data sequence includes multiple iterations of the hardware address of the wireless network card associated with that device. While in a reduced power or “sleep mode”, the wireless network card monitors wireless channels for packets containing a wake-up data sequence. If a wake-up data sequence is received, the sequence is matched against the hardware address information for that network card. If a match is determined, the network card sends a signal to the computing device causing full system power to be restored. A signal is sent to the network confirming that the device has been successfully woken from the sleep mode.
    Type: Application
    Filed: July 7, 2008
    Publication date: December 18, 2008
    Applicant: CONEXANT SYSTEMS, INC.
    Inventor: Michael Paljug
  • Publication number: 20080310296
    Abstract: 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 to a time-domain compensation signal comprising only PAR tones.
    Type: Application
    Filed: June 13, 2008
    Publication date: December 18, 2008
    Applicant: CONEXANT SYSTEMS, INC.
    Inventors: Amitkumar Mahadevan, Patrick Duvaut, Harish Jethanandani, Rahul Garg
  • Patent number: 7466758
    Abstract: The present invention provides a method and apparatus for a new interleaver adaptation scheme that achieves “error free” and zero delay (interleaving—triangular) or near zero delay variation (interleaving—GCI), and with easier implementation but no additional memory required. The dummy insertion methods and systems embodiments of the invention provide an effective dummy byte insertion scheme for applications that require seamless on-line rate changes, e.g., SRA (seamless rate adaptation), DRR (dynamic rate repartitioning) and adaptive INP (impulse noise protection).
    Type: Grant
    Filed: December 9, 2005
    Date of Patent: December 16, 2008
    Assignee: Conexant Systems, Inc.
    Inventors: Tao Xue, Massimo Sorbara, Ho-Ming Lin
  • Publication number: 20080298290
    Abstract: Stations in standby mode periodically wake up to check for buffered data at the access points. Traditionally, the information is available by checking the periodic beacon frame for a traffic indication map (TIM). Unfortunately, the length of beacons has steadily increased with the progression of the various wireless standards requiring stations to wake up for longer periods to merely check for buffered data. Several approaches are disclosed which address this shortcoming, including the broadcast of TIM frames, the partial reception of beacon frames and the use of an embedded TIM frame within a beacon frame.
    Type: Application
    Filed: March 12, 2008
    Publication date: December 4, 2008
    Applicant: CONEXANT SYSTEMS, INC.
    Inventor: Maarten Menzo Wentink