Patents Issued in September 2, 2008
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Patent number: 7420973Abstract: Context selection in a network element through subscriber flow switching. According to one embodiment of the invention, authentication, authorization and accounting is performed for a subscriber desiring to connect to a plurality of services on different contexts. In response, bindings are established to a plurality of contexts for the subscriber. In response to receiving a traffic packet from the subscribed, at least certain header information from the traffic packet is accessed. Based on at least the accessed header information, one of the plurality of contexts is selected for that traffic packet.Type: GrantFiled: February 9, 2004Date of Patent: September 2, 2008Assignee: Redback Networks Inc.Inventors: Onno Mark Becker Hof, Said Ouissal
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Patent number: 7420974Abstract: In an ATM network, data loss caused by pre-programmed network optimizations can be reduced or avoided if a record of such optimizations is made, and if, prior to another optimization, some event occurs. The detection of some external event should indicate that another optimization is warranted.Type: GrantFiled: January 6, 2004Date of Patent: September 2, 2008Assignee: AT&T Corp.Inventors: John D. Brandt, Nicholas D. De Trana, Arthur G. Deacon, Craig L. DeCaluwe, Hossein Eslambolchi
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Patent number: 7420975Abstract: In one embodiment, the invention is an apparatus. The apparatus includes a network processor interface suitable for coupling to a network processor. The apparatus further includes a central processor interface suitable for coupling to a central processor. The apparatus also includes a protocol determination logic block to determine a protocol type of data in a packet and steer the packet to either the central processor interface or the network processor interface based on the protocol type of data.Type: GrantFiled: December 20, 2002Date of Patent: September 2, 2008Assignee: Cypress Semiconductor CorporationInventors: Velamur Krishnamachari Vasudevan, Dinesh Annayya
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Patent number: 7420976Abstract: A hardware-based policy engine that employs a policy cache to process packets of network traffic. The policy engine includes a stream classifier that associates each packet with at least one action processor based on data in the packet, and the action processor further acts on the packets based on the association determined by the stream classifier.Type: GrantFiled: February 3, 2006Date of Patent: September 2, 2008Assignee: WatchGuard Technologies, Inc.Inventor: YeeJang James Lin
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Patent number: 7420977Abstract: A system of switches having a memory/command bus having a first interface, a second interface and a third interface. A memory is connected to the third interface of the memory/command bus. The memory has a first memory address. A first switch monitors the memory/command bus and interprets information written to the first memory address as proxy information. The first switch is connected to the first interface of the memory/command bus. The second switch monitors the memory/command bus and interprets information written to the first memory address as proxy information. The second switch is connected to the second interface of the memory/command bus.Type: GrantFiled: May 24, 2001Date of Patent: September 2, 2008Assignee: Broadcom CorporationInventors: Jason Fan, Michael Sokol
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Patent number: 7420978Abstract: A telecommunication service charges for voice calls entering a network over a particular time period, such as a billing period. A parameter or parameters related to the number of information units (e.g., packets, bytes or bits) used to transmit the plurality of voice calls over the network is measured. A charge for the plurality of voice calls is computed based on the one or more parameters measured. The one or more parameters may be used to compute a charge for the plurality of voice calls based on the total number of information units transmitted, average number of information units transmitted, peak information units transmitted over the billing period or some combination thereof.Type: GrantFiled: October 30, 2003Date of Patent: September 2, 2008Inventors: J. Michael Holloway, Samuel R. Shiffman
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Patent number: 7420979Abstract: One physical VLAN server provides a plurality of VLANs with services. VLANs #1 to #3 are connected to the VLAN server though a switching hub. The VLAN server includes server processes #1 to #3 corresponding to the VLANs #1 to #3, respectively, for providing the VLANs with services. The server processes #1 to #3 each have internal IP addresses N1, N2, and N3. The VLAN server has external IP addresses G1, G2, and G3 for the VLANs #1 to #3, respectively.Type: GrantFiled: July 26, 2004Date of Patent: September 2, 2008Assignee: Hitachi Communcation Technologies, Ltd.Inventors: Daiki Nozue, Hiroaki Miyata, Norihiro Kambe, Shinsuke Shimizu
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Patent number: 7420980Abstract: A method of assigning cells in a superframe using digraph link information in a network of nodes is disclosed. The method comprises determining a total number of desired digraph links in the network of nodes wherein a digraph link is a directional link specifying routing information at each node in the network between said node and a second node, and wherein the network of nodes includes a plurality of nodes each with a plurality of digraph links. The method further comprises selecting a superframe size at least large enough to accommodate the total number of desired digraph links and assigning each desired digraph link to a cell in the superframe wherein each cell in the superframe specifies a synchronized time and frequency communication plan.Type: GrantFiled: June 13, 2005Date of Patent: September 2, 2008Assignee: Dust Networks, Inc.Inventors: Kristofer S. J. Pister, Robert M. Shear
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Patent number: 7420981Abstract: A wireless communication system is described for allocating limited network access according to priorities designated for requested transactions of wireless communications. The wireless network has a number of access links for transmitting transactions for wireless communications. A plurality of wireless communications devices request transmission of transactions on the wireless network. A designated priority level is associated with each transaction. In response to the transaction requests, an access control manager in the wireless network schedules transmission of transactions when all of the plurality of access links are occupied, by authorizing a transmission of a transaction of higher priority than another transaction that is being transmitted, and discontinuing the transmission of the transaction of lower priority.Type: GrantFiled: October 12, 2005Date of Patent: September 2, 2008Assignee: AT&T Delaware Intellectual Property, Inc.Inventors: Samuel N. Zellner, Mark J. Enzmann
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Patent number: 7420982Abstract: A method and system for keeping an arbitrated loop open during a frame gap using a fiber channel switch element is provided. The switch element includes a port control module having a receive and transmit segment, wherein the transmit segment activates a timer whose value determines a duration during which the arbitrated loop remains open; determines if a last frame from a sequence of frames from a source port has been transmitted; modifies the timer value if a higher priority frame for transmission is unavailable; and keeps the arbitrated loop open until the timer reaches a certain value. If a higher priority frame is available for transmission before the timer value is modified then the higher priority frame is transmitted and the timer value is re-initialized.Type: GrantFiled: July 20, 2004Date of Patent: September 2, 2008Assignee: QLogic, CorporationInventors: Frank R. Dropps, Ernest G. Kohlwey, Gary M. Papenfuss
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Patent number: 7420983Abstract: Methods and apparatus for the dynamic assignment of re-assembly queues to multiple connections in a communications system are described. In a preferred embodiment of the invention an ATM to MPLS mediation application is implemented. In the mediation process ATM cells are assigned to re-assembly queues where they are converted to MPLS packets for transmission over a MPLS tunnel. Typically there are many more connections than re-assembly queues which necessitates a dynamic assignment of the re-assembly queues to ensure efficient operation of the system. Re-assembly queues are serviced based on either a cell count or a timing factor.Type: GrantFiled: March 13, 2003Date of Patent: September 2, 2008Assignee: Alcatel LucentInventor: Peter Donovan
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Patent number: 7420984Abstract: Methods and apparatuses associated with multi-phase wireless handshaking. A user terminal enters handshaking with an access point. The access point may respond to an access request of the user terminal with an access assignment, and alternatively, with a message indicating an assignment will not be presently given. The handshaking process could then be completed at a later time.Type: GrantFiled: May 6, 2004Date of Patent: September 2, 2008Assignee: ArrayComm LLCInventors: John Chen, Brett Schein, Prasanna Kannan, Tae-In Hyon
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Patent number: 7420985Abstract: The invention relates to a method for operating an isochronous, cyclic communication system, wherein one communication cycle can be subdivided into a first part for real-time communication and a second part for non-real-time communication. The communication system comprises subscribers and a memory is provided to store configuration data in each subscriber. The inventive method comprises the following steps: the communication system is operated with first configuration data for real-time communication; second configuration data is transmitted for real-time communication in a second part of one or several communication cycles; the second configuration data is stored in the memories of the subscribers; a transfer time indicating the moment in time when transfer occurs from the first configuration data to the second configuration data.Type: GrantFiled: September 13, 2002Date of Patent: September 2, 2008Assignee: Siemens AktiengesellschaftInventors: Dieter Brückner, Franz-Josef Götz, Dieter Klotz, Jürgen Schimmer
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Patent number: 7420986Abstract: The present invention is directed toward a method and apparatus for detecting collisions on a shared access network. In accordance with the present invention, two or more RF modulated signals having a plurality of different phase states are transmitted to a central controller, wherein two or more of the transmitted signals collide at the central controller. The collision detection system then determines a characteristic of the collision signal, such as the absolute value of the peak amplitude of the collision signal. The collision detection system then compares the characteristic with a plurality of thresholds and determines the number of RF modulated signals that collided as a function of the comparison. The method for detecting collisions may further include monitoring a plurality of collision events to determine a characteristic, such as the absolute value of the peak amplitude of the collision signal, of each of the collision events.Type: GrantFiled: November 2, 2000Date of Patent: September 2, 2008Assignee: Broadcom CorporationInventors: Daniel H. Howard, Dolors Sala
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Patent number: 7420987Abstract: An arbiter performs arbitration over a plurality of queues and provides data to a plurality of mutually exclusive destinations using combination logic that logically combines a plurality of mutually exclusive vectors into a combination vector. Each of the mutually exclusive vectors corresponds to one of the plurality of mutually exclusive destinations. A number of vector arbiters perform arbitration on each mutually exclusive vector to select a position within the mutually exclusive vector. A combination arbiter performs arbitration on the combination vector to determine a position within the combination vector, which corresponds to the next queue to be serviced. A comparison element compares the position within a mutually exclusive vector and the position within the combination vector to determine the destination of the data within the next queue to be serviced.Type: GrantFiled: July 25, 2002Date of Patent: September 2, 2008Assignee: Juniper Networks, Inc.Inventors: Debashis Basu, Edwin Su
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Patent number: 7420988Abstract: Frames are relayed through a packet network by pre-pending a packet header to the frames. The packet may be formed in response to a timing mechanism indicating that the frames have been buffered for more than a threshold time interval. Alternatively, the packet may be formed in response to buffering a threshold number of frames. The packet is relayed through the packet network to an egress device. The egress device removes the header from the packet, and forwards the frames via one or more virtual circuits.Type: GrantFiled: February 14, 2003Date of Patent: September 2, 2008Assignee: Juniper Networks, Inc.Inventor: Stu Grossman
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Patent number: 7420989Abstract: The Resource Reservation Protocol (RSVP) is to gather outgoing interface identification information (e.g., outgoing interface ID's or IP addresses) for each node in a primary path. This information is “recorded” in an opaque object (referred to herein as the “RECORD PRIMARY PATH” or “RPP” object). In accordance with the present invention, the information contained in the opaque object is stored in two databases for each node, with local interface information of a particular node being stored in its Local Links Database (LLDB), and information identifying the primary links that affect the backup bandwidth calculation for that node being stored in its External Links Database (ELDB). Each node has its own LLDB and ELDB (or has the LLDB and ELDB data stored in a larger database in such a way that it is can be separately accessible on a node-by-node basis) so that, for each node, the information can be obtained and used.Type: GrantFiled: September 30, 2004Date of Patent: September 2, 2008Assignee: Lucent Technologies Inc.Inventors: Hua Autumn Liu, Ajay Sathyanath
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Patent number: 7420990Abstract: Apparatus and methods allocate I/O bandwidth of an electrical component, such as an IC, by configuring an I/O interface into various types of interfaces. In an embodiment of the present invention, an I/O interface is configured into either a bidirectional contact, unidirectional contact (including either a dedicated transmit or dedicated receive contact) or a maintenance contact used in a maintenance or calibration mode of operation. The I/O interface is periodically reconfigured to optimally allocate I/O bandwidth responsive to system parameters, such as changing data workloads in the electronic components.Type: GrantFiled: November 10, 2006Date of Patent: September 2, 2008Assignee: Rambus Inc.Inventors: Michael Ching, Steven Woo
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Patent number: 7420991Abstract: A method for sending/receiving a TCP segment is provided. The sending process includes, determining if a TCP port can be offloaded; saving a host system's time stamp value; replacing a host system's time stamp value with a TCP offload engine (“TOE”) adapter's time stamp value; and sending the TCP segment via the TOE adapter. The receiving process includes verifying if a TCP port is being offloaded by a host system to the TOE adpter; retrieving the host system's time stamp value; and inserting the host system's time stamp value in the received TCP segment before the forwarding the received TCP segment to the host system.Type: GrantFiled: April 1, 2005Date of Patent: September 2, 2008Assignee: QLOGIC, CorporationInventors: Ying P. Lok, Ronald M. Mercer, David C. Somayajulu, Shashank Pandhare, Michael I. Thompson
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Adaptive network traffic compression mechanism including dynamic selection of compression algorithms
Patent number: 7420992Abstract: An adaptive compression mechanism that dynamically selects compression algorithms applied to network application traffic to improve performance. One implementation includes an arbitration scheme that reduces the impact on computing resources required to analyze different compression algorithms for different network applications. The adaptive compression functionality of the present invention can be integrated into network application traffic management or acceleration systems.Type: GrantFiled: March 17, 2005Date of Patent: September 2, 2008Assignee: Packeteer, Inc.Inventors: Li Fang, Mary Louise Laier -
Patent number: 7420993Abstract: A variable length code multiplexer multiplexes a plurality of input codes (102) including a variable length code into a multiplexed code (121) and outputs the multiplexed code (121). The multiplexer includes a forward direction multiplexing unit (22) for multiplexing the plurality of input codes (102) one by one so that they are running in a forward direction from a head of the multiplexed code (121) to a tail of the multiplexed code (121), a backward direction multiplexing unit (23) for multiplexing the plurality of input codes (102) one by one so that they are running in a backward direction from the tail of the multiplexed code (121) to the head of the multiplexed code (121), and a selection unit (25) for selecting either the forward direction multiplexing unit (22) or the backward direction multiplexing unit (23) for each of the plurality of input codes (102).Type: GrantFiled: August 19, 2002Date of Patent: September 2, 2008Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Hirohisa Tasaki
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Patent number: 7420994Abstract: A pulsed cascaded Raman laser (10) includes a pulsed light source (102) for generating a pulsed light (104) having an optical spectrum centered at a source wavelength. A non-linear Raman conversion fiber (106) is coupled to the pulsed light source (102). The pulsed light (104) traverses the nonlinear Raman conversion fiber (106) and the source power at the source wavelength is converted to a power output of an output signal (108) having an output wavelength longer than the source wavelength by a cascaded Stimulated Raman Scattering process, such that most of the source power is converted to the power of the last Stokes order in a single pass through the non-linear Raman conversion fiber (106).Type: GrantFiled: March 4, 2005Date of Patent: September 2, 2008Assignee: Corning IncorporatedInventors: Andrey Korolev, Dmitri V. Kuksenkov, Vladimir Nazarov
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Patent number: 7420995Abstract: A simultaneously mode-locked, Q-switched laser is configured to prevent loss of mode lock during laser operation. A preferred embodiment prevents loss of mode lock by operating the laser between the Q-switched pulses with a residual level of laser power sufficient to maintain a mode-locked state. The residual laser power output can be blocked by a pulse picking device.Type: GrantFiled: December 5, 2006Date of Patent: September 2, 2008Assignee: Electro Scientific Industries, Inc.Inventor: Yunlong Sun
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Patent number: 7420996Abstract: An extremely versatile diode laser assembly is provided, the assembly comprised of a plurality of diode laser subassemblies mounted to a stepped cooling block. The stepped cooling block allows the fabrication of a close packed and compact assembly in which individual diode laser subassembly output beams do not interfere with one another.Type: GrantFiled: March 17, 2006Date of Patent: September 2, 2008Assignee: nLight Photonics CorporationInventors: Derek E. Schulte, Yu Yan, Robert J. Martinsen, Aaron L. Hodges, Scott R. Karlsen
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Patent number: 7420997Abstract: Particular embodiments of the present invention relate generally to semiconductor lasers and laser scanning systems and, more particularly, to schemes for controlling semiconductor lasers. According to one embodiment of the present invention, a laser is configured for optical emission of encoded data. At least one parameter of the optical emission is a function of a drive current IGAIN injected into the gain section of the semiconductor laser and one or more additional drive currents I/VPHASE, I/VDBR. Mode selection in the semiconductor laser is altered by perturbing at least one of the additional drive currents I/VPHASE, I/VDBR with a perturbation signal I/VPTRB to alter mode selection in the semiconductor laser such that a plurality of different emission modes are selected in the semiconductor laser over a target emission period.Type: GrantFiled: September 13, 2007Date of Patent: September 2, 2008Assignee: Corning IncorporatedInventors: Vikram Bhatia, Jacques Gollier, Martin Hai Hu, David August Sniezek Loeber, Daniel Ohen Ricketts
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Patent number: 7420998Abstract: A semiconductor laser device has a front surface electrode formed by Au plating, a rear surface electrode formed by Au plating, an anti-adhesive film only on the front surface electrode and made of a material that does not react with Au, and a coating film that covers an end face on a light emitting side and an end face opposite the light emitting side. The anti-adhesive films are located on the four corners of the front surface electrode.Type: GrantFiled: March 23, 2005Date of Patent: September 2, 2008Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Junichi Horie
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Patent number: 7420999Abstract: A nitride semiconductor laser element, comprises a substrate, a nitride semiconductor layer laminated on said substrate and having a ridge on its surface, a first protective film that covers said nitride semiconductor layer, and an electrode form on the ridge and the first protective film, wherein the first protective film covers part of the nitride semiconductor layer surface in a contact state, and covers from the periphery around the base of the ridge to the side faces of the ridge in a non-contact state, resulting in a cavity being disposed from said ridge side faces to the ridge base periphery.Type: GrantFiled: March 6, 2007Date of Patent: September 2, 2008Assignee: Nichia CorporationInventor: Shingo Masui
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Patent number: 7421000Abstract: A semiconductor laser device having a waveguide constructed in a stack of layers including, on a substrate that is transparent and has a refractive index ns for laser light, a first clad layer of a refractive index nc1, a second clad layer of a refractive index nc2, a third clad layer of a refractive index nc3, a first conductivity type guide layer of a refractive index ng, an active quantum well layer, a second conductivity type guide layer, a second conductivity type clad layer, and a second conductivity type contact layer deposited in that order, wherein the waveguide has an effective refractive index ne, and the relationship nc2<(nc1, nc3)<ne<(ns, ng) is satisfied.Type: GrantFiled: February 9, 2007Date of Patent: September 2, 2008Assignee: Sharp Kabushiki KaishaInventors: Mototaka Taneya, Yukio Yamasaki, Shigetoshi Ito
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Patent number: 7421001Abstract: A device contains at least one leaky waveguide layer, and has a transparent substrate, having a higher refractive index. The leakage loss of the waveguide exceeds the modal gain needed to initiate waveguide lasing. The leaky emission is going into the substrate at a certain angle, is reflected from the substrate back surface, and returns towards the leaky waveguide layer exhibiting constructive or destructive interference. As the leakage emission is returned to the active medium, the low threshold current density lasing is possible. As the leakage angle is defined for a given wavelength, interference enables lasing only at certain wavelengths making it possible to realize wavelength-selectivity. The lobes of the output emission can be made arbitrarily narrow by increasing the thickness of the substrate and the exit angle of the lobes is controlled by the leakage angle of the waveguide.Type: GrantFiled: June 16, 2006Date of Patent: September 2, 2008Assignee: PBC Lasers GmbHInventors: Vitaly Shchukin, Nikolai Ledentsov
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Patent number: 7421002Abstract: A laser-induced optical wiring apparatus includes a substrate, first and second light-reflecting members provided on the substrate separately from each other, an optical waveguide provided on the substrate for optically coupling the first and second light-reflecting members to form an optical resonator, a first optical gain member provided across the optical waveguide and forming a laser oscillator along with the first and second light-reflecting members, and a second optical gain member provided across the optical waveguide separately from the first optical gain member, and forming another laser oscillator along with the first and second light-reflecting members.Type: GrantFiled: September 14, 2006Date of Patent: September 2, 2008Assignee: Kabushiki Kaisha ToshibaInventor: Hideto Furuyama
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Patent number: 7421003Abstract: An organic distributed feedback layer, which comprises a resonator in a double layer structure comprising a photo-induced mass transfer material layer and an organic fluorescence layer, provided as an under layer below the former layer, where the photo-induced mass transfer material is a polymer material having an azobenzene skeleton represented by the following chemical structure: has such a characteristic that the laser emission wavelength is programmable by changing interference exposure conditions for forming gratings of the photo-induced mass transfer material.Type: GrantFiled: September 30, 2004Date of Patent: September 2, 2008Assignee: RikenInventors: Takashi Ubukata, Takashi Isoshima
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Patent number: 7421004Abstract: Broadband, ultra wideband and ultra narrowband (UWN) reconfigurable, interoperable communication and broadcasting system architectures, combinations and hybrids of ultra wideband (UWB), ultra narrowband (UNB) and efficient broadband wireless, baseband, intermediate frequency (IF) and radio frequency (RF) implementations for Bit Rate Agile (BRA) reconfigurable and interoperable systems, Adaptive Modulation and Coding (AMC). Processing the data signals, of clock signals, and/or carrier cycles waveforms leads to shaped radio-frequency (RF) cycles, waveforms and wavelets. With Multiple Input Multiple Output (MIMO) diversity and protection system configuration the performance and capacity of these systems may be further enhanced.Type: GrantFiled: December 28, 2004Date of Patent: September 2, 2008Inventor: Kamilo Feher
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Patent number: 7421005Abstract: A frequency hopping sequence generator system (40) for use in a radio telecommunications system utilizes variable frequency offsets (FO) to determine a frequency hopping sequence for use in communication between a mobile station and a network node. The frequency hopping sequence generator comprises a frequency offset hopping generator (42) which chooses the variable frequency offsets so that the frequency hopping sequence provides intra-cell interference diversity. For each mobile station, the frequency offset hopping generator determines a frequency offset index (FOI) which is mapped to one of plural possible frequency offsets (FO). The frequency offset index (and thus the corresponding frequency offset) is determined to provide the frequency hopping sequence with both interference diversity and orthogonality. The frequency offset index has an inter-cell component (that provides, e.g.Type: GrantFiled: October 9, 2003Date of Patent: September 2, 2008Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Stephen Craig, Henrik Nyberg
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Patent number: 7421006Abstract: A system and method improves ECCM and data payload for a multi-h continuous phase modulated waveform with the addition of frequency hopping capabilities. The system and method exploit the short constraint length and rotational invariance of the multi-h CPM waveform to enable frequency hopping using current system capabilities. The transmitted data is structured such that the initial phase state of each hopping frame is in the zero state and the final phase state of each hopping frame is cycled to zero by the addition of flushing symbols and transition symbols. The transition symbols allow the oscillator to change frequency without disrupting the phase progression. The system and method uses synchronous demodulation of the transmitted data at a plurality of phase offsets and determines the best phase offset based on the total sum of the branch metrics for each symbol and phase offset.Type: GrantFiled: March 16, 2004Date of Patent: September 2, 2008Assignee: Harris CorporationInventor: Paul Edward Voglewede
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Patent number: 7421007Abstract: The present invention relates to a digital transmitting/receiving circuit (1) intended to be mounted on at least one source and on at least one concentrator exchanging binary symbols with the said sources, the said circuit (1) comprising a transmitter (2) capable of transmitting the said binary symbols and a receiver (4) capable of receiving symbols transmitted by a source, the circuit (1) being characterized in that the transmitter (2) comprises a first module (20) intended to generate at least one binary code for effecting the spectral spreading of symbols to be transmitted and a second module (22) intended to generate at least one internal clock signal for synchronizing the reception of symbols transmitted by a source, and in that the said receiver comprises means (46, 48) for detecting new sources of transmission and means (49) for generating synchronization signals and power control signals corresponding to each new source detected.Type: GrantFiled: December 27, 2001Date of Patent: September 2, 2008Assignee: Commissariat a l'Energie AtomiqueInventors: Didier Lattard, Jean-Rene Lequepeys, Didier Varreau, Laurent Ouvry
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Patent number: 7421009Abstract: A noise power estimation apparatus is disclosed. The noise power estimation apparatus includes: a part for calculating correlation between a received signal and a pilot signal so as to obtain a received power of the pilot signal for each path; a part for removing a multipath interference component from the received power of the pilot signal by using a predetermined power ratio between the pilot signal and a data signal so as to obtain a corrected received power of the pilot signal; a part for estimating an estimated total power of the pilot signal and the data signal included in the received signal based on the corrected received power and the predetermined power ratio; and a part for subtracting the estimated total power from a total power of the received signal so as to obtain a noise power.Type: GrantFiled: May 13, 2005Date of Patent: September 2, 2008Assignee: NTT DoCoMo, Inc.Inventors: Junichiro Kawamoto, Noriyuki Maeda, Kenichi Higuchi, Mamoru Sawahashi
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Patent number: 7421010Abstract: The invention provides a mobile communication terminal which uses both an extrapolation pilot signal and an interpolation pilot signal to assure a high precision in channel estimation and a high synchronous detection capacity without using TPC control or the like. The apparatus includes a first pilot signal despreading section for despreading a first pilot signal spread with a spread code different from a spread code of a communication channel, a second pilot signal despreading section for despreading a second pilot signal inserted in a data signal and spread with a spread code same as the spread code for the data signal, first and second complex calculation sections, and a correction amount output section for outputting a phase correction amount for phase correction using the results from the first and second complex calculation sections. The apparatus can be applied to a mobile communication terminal of, for example, the CDMA communication method.Type: GrantFiled: March 26, 2002Date of Patent: September 2, 2008Assignee: Fujitsu LimitedInventor: Tetsuya Kikuchi
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Patent number: 7421011Abstract: A method for performing an acquisition to a code-modulated spread spectrum signal comprises receiving the transmitted signal, sampling the received signal to form samples, forming at least one reference code corresponding to a code used in the modulation and forming a non-coherent search matrix on the basis of said samples. The non-coherent search matrix comprises elements in at least a first and a second dimension. The first dimension of the non-coherent search matrix represents the same frequency deviation but different code phases of the received signal, and the second dimension of the non-coherent search matrix represents the same code phase but different frequency deviations of the received signal. Each element is addressable in the first dimension by a first index and in the second dimension by a second index.Type: GrantFiled: May 27, 2004Date of Patent: September 2, 2008Assignee: Nokia CorporationInventors: Samuli Pietilä, Mikko Kokkonen
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Patent number: 7421012Abstract: A communication system for communicating data packets includes a receiver subsystem. The receiver subsystem comprises a first antenna, and a second antenna. A direct sequence spread-spectrum demodulator communicates with the first and second antennas. The demodulator is configured to correlate a spreading code with a preamble of each data packet to produce a spreading codeword. The spreading code includes a predetermined number of chips. A signal quality measurement device is responsive to the direct sequence spread-spectrum demodulator. The device is configured to measure signal quality values corresponding to each of the first and second antennas for each data packet after correlation with the spreading code and to select one of said first and second antennas on the basis of the measured signal quality values.Type: GrantFiled: June 9, 2006Date of Patent: September 2, 2008Assignee: Marvell International, Ltd.Inventors: Weishi Feng, Hsiao Tang, Guorong Hu, Yungping Hsu
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Patent number: 7421013Abstract: A receiver in an OFDM system may include a joint maximum likelihood (ML) estimator that estimates both time offset and frequency offset. The estimator may use samples in an observation window to estimate the time offset and frequency offset.Type: GrantFiled: December 30, 2004Date of Patent: September 2, 2008Assignee: Marvell International Ltd.Inventors: Jungwon Lee, Hui-Ling Lou, Dimitrios-Alexandros Toumpakaris
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Patent number: 7421014Abstract: A method for channel bonding begins when a master transceiver receives a channel bonding sequence. The process continues with the master transceiver generating a channel bonding request and transmitting it and channel bonding configuration information to the slave transceiver. The process continues with each slave receiving the channel bonding sequence, the channel bonding request and the channel bonding configuration information. The process continues as each slave processes the channel bonding request and the channel bonding sequence in accordance with the channel bonding configuration information to determine individual slave channel bonding start information. The process continues as the master processes the channel bonding sequence in accordance with the channel bonding configuration information and the channel bonding request to determine master channel bonding start information.Type: GrantFiled: September 11, 2003Date of Patent: September 2, 2008Assignee: XILINX, Inc.Inventors: Joseph Neil Kryzak, Aaron J. Hoelscher, Thomas E. Rock
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Patent number: 7421015Abstract: In general, various methods and apparatus are described that use a multi-tone receiver. The multi-tone receiver detects data in a multiple tone signal. The receiver has a detector module to measure a noise power level present in the system and to detect for an asymmetric Gaussian noise source in the background noise. An equivalent noise power is obtained by applying a compensating gain factor to the asymmetrical noise source. The gain factor is used when the detector indicates that the asymmetric Gaussian noise source exists in the background noise. Any bit-loading algorithm that is based on a symmetric Guassian noise source assumption can also be used with asymmetrical Guassian noise sources if this gain factor is applied.Type: GrantFiled: February 26, 2004Date of Patent: September 2, 2008Assignee: 2Wire, Inc.Inventor: Hossein Sedarat
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Patent number: 7421016Abstract: Techniques to test a wireless communication link. A traffic channel is tested via a test data service option (TDSO) that may be negotiated and connected similar to other services. Test parameters values may be proposed, accepted or rejected, and negotiated. Test data for a channel is generated based on a defined data pattern or a pseudo-random number generator. Sufficient test data may be generated based on the generator for a test interval, stored to a buffer, and thereafter retrieved from a particular section of the buffer to form data block(s) for each “active” frame. The traffic channel may be tested using discontinuous transmission. A two-state Markov chain determines whether or not to transmit test data for each frame. The average frame activity and average burst length are defined by selecting the probabilities for transitioning between the ON/OFF states of the Markov chain, which may be driven by a second generator.Type: GrantFiled: January 14, 2003Date of Patent: September 2, 2008Inventors: Scott Eduard Fischel, Idreas A. Mir
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Patent number: 7421017Abstract: A linear filter feeds back an error signal generated using the output of an adaptive filter to a learning circuit. The learning circuit learns the coefficients of the adaptive filter using the error signal. The coefficients of the linear filter are determined depending on the generation method of a target signal for error minimization. In a signal interpolation type timing recovery digital filter, the coefficients of an inverse interpolation filter are determined in such a way as to minimize an error of a signal after interpolation.Type: GrantFiled: August 12, 2003Date of Patent: September 2, 2008Assignee: Fujitsu LimitedInventor: Motomu Takatsu
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Patent number: 7421018Abstract: In one aspect, the present invention provides a system and method for selecting precursor equalizer coefficients and a serializer deserializer (SERDES) incorporating the system or the method. In one embodiment, the system includes: (1) a cost definer configured to generate an eye height cost function based on continuous-time channel and crosstalk symbol responses pertaining to a particular serial link and (2) a cost evaluator associated with the cost definer and configured to evaluate the eye height cost function based on a particular criterion thereby to produce coefficients for a precursor equalizer to be applied with respect to the particular serial link.Type: GrantFiled: April 28, 2004Date of Patent: September 2, 2008Assignee: Texas Instruments IncorporatedInventors: Kofi D. Anim-Appiah, Nirmal C. Warke, Song Wu
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Patent number: 7421019Abstract: A hierarchical adaptive equalizer and a design method thereof are disclosed. The design method divides N delay elements into a plurality of adaptive algorithms, each of the adaptive algorithms having ? delay elements. The design method logically structures a hierarchical tree with the adaptive algorithms. The hierarchical tree comprises ? levels. A top first level of the hierarchical tree comprises ???1 adaptive algorithms. A top second level of the hierarchical tree comprises ???2 adaptive algorithms. A bottom level of the hierarchical tree comprises an adaptive algorithm.Type: GrantFiled: June 18, 2004Date of Patent: September 2, 2008Assignee: Chung Shan Institute of Science and Technology, Armaments Bureau, M.N.D.Inventors: Chien-Hsing Liao, Wei-Min Chang, Tai-Kuo Woo, Shih-Che Lin, Jyh-Horng Wen
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Patent number: 7421020Abstract: A channel equalizing device and method of a digital broadcasting receiving system in which a digital broadcasting signal received over a channel is compensated for a channel distortion to recover an original signal is provided. The channel equalizing device includes: a channel estimating unit for estimating and outputting a channel impulse response of a signal, which is received over a transmission channel; a channel characteristic detecting unit for determining as to whether a channel characteristic is a dynamic channel or a static channel by using a difference between the channel impulse response estimated at a current time and outputted from the channel estimating unit and the channel impulse response estimated at a previous time; and a channel equalizing unit for controlling a parameter of an internal filter depending on the channel characteristic detected by the channel characteristic detecting unit, to compensate the received signal for the channel distortion.Type: GrantFiled: December 13, 2004Date of Patent: September 2, 2008Assignee: LG Electronics Inc.Inventors: Kyung Won Kang, In Hwan Choi
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Patent number: 7421021Abstract: An adaptive signal equalizer with a feedforward filter in which the feedback error signal and corresponding incoming data signal are dynamically aligned in time using signal interpolation, and further, to control the precursor/postcursor filter taps configuration, thereby producing more adaptive filter tap coefficient signals for significantly improved and robust signal equalization.Type: GrantFiled: June 7, 2007Date of Patent: September 2, 2008Assignee: Inphi CorporationInventors: Venugopal Balasubramonian, Jishnu Bhattacharjee, Edem Ibragimov, Debanjan Mukherjee, Abhijit Phanse, Abhijit Shanbhag, Qian Yu
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Patent number: 7421022Abstract: A continuous time electronic dispersion compensation architecture using feed forward equalization and a non-linear decision feedback equalization forms an output signal by a linear combination of successively delayed versions of the input signal and the sliced output signal weighted by appropriate coefficients. A selected number of taps in the mixer used to generate a corresponding number of coefficients for use in the feed forward equalizer are held to a selected voltage to ensure that the coefficients associated with these two taps do not drift. This causes the other coefficients to converge to a unique minimum square error value. In one embodiment the selected voltage is the maximum system voltage.Type: GrantFiled: April 27, 2005Date of Patent: September 2, 2008Assignee: Inphi CorporationInventors: Prashant Choudhary, Venugopal Balasubramonian, Jishnu Bhattacharjee, Debanjan Mukherjee, Abhijit Phanse, Abhijit Shanbhag, Qian Yu
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Patent number: 7421023Abstract: An image information conversion apparatus and method by which picture quality deterioration caused by conversion from inputted MPEG2 image compression information into MPEG4 image compression information to be outputted is prevented. When an I picture of an MPEG2 bit stream is to be converted into a P-VOP of an MPEG4 bit stream based on an estimated value of the complexity for each VOP, a scene change detection section detects whether or not the I picture includes a scene change. If a scene change is detected by the scene change detection section, then a GOV structure determination section determines that conversion of the I picture of the MPEG2 bit stream into a P-VOP of an MPEG4 bit stream should not be performed.Type: GrantFiled: April 25, 2005Date of Patent: September 2, 2008Assignee: Sony CorporationInventors: Kazushi Sato, Kuniaki Takahashi, Teruhiko Suzuki, Yoichi Yagasaki