Patents Issued in August 14, 2007
  • Patent number: 7257137
    Abstract: A tuneable laser is disclosed, including a gain section with first and second comb reflectors to one side thereof. The two reflectors each provide combs with substantially uniform spacings, the spacings differing as between the combs. Each comb reflector can be tuned so as to shift the reflective peaks of the combs, thus allowing alignment of a single reflective peak at a chosen wavelength which is the same in both combs, forming a supermode. This supermode has an intensity greater than the threshold of the gain section and thus the laser produces an output at that selected wavelength.
    Type: Grant
    Filed: July 15, 2002
    Date of Patent: August 14, 2007
    Assignee: Bookham Technology, PLC
    Inventors: David James Robbins, Peter John Williams
  • Patent number: 7257138
    Abstract: The semiconductor optical device is mounted junction down on a mounting plate via the solder metal of the mounting plate. The electrode of the semiconductor optical device facing the mounting plate is partially coated with a dielectric film and the dielectric film is in contact with the solder metal on the mounting plate. The reaction between the semiconductor optical device and the solder metal of the mounting plate can be suppressed without deteriorating the thermal conductivity between the semiconductor optical device and the mounting plate. Therefore, it is possible to improve the reliability of the semiconductor optical device mounted in the junction down form since diffusion of the solder metal into the semiconductor can be prevented.
    Type: Grant
    Filed: June 30, 2003
    Date of Patent: August 14, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Sato, Masahiro Aoki, Shinji Tsuji
  • Patent number: 7257139
    Abstract: A semiconductor laser device has a striped structure for injecting carriers and includes a first electrically-conductive cladding layer, an active layer, and a second electrically-conductive cladding layer that are formed on a substrate. A width of the stripe changes along a resonator direction, a difference between L1 and Lt is within 200 ?m, and Rf<Rr, where L1 is a distance from a front end face to a position at which the width of the stripe is minimal, L is a length of a resonator of the semiconductor laser device, Rf is a reflectivity of the front end face, Rr is a reflectivity of a rear end face, and Lt is a distance expressed by L×Loge(Rf)/Loge(Rf×Rr). The saturation of a light emission efficiency is suppressed in a high power operation, allowing a stable fundamental transverse mode oscillation.
    Type: Grant
    Filed: January 20, 2005
    Date of Patent: August 14, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Toru Takayama
  • Patent number: 7257140
    Abstract: A laser device is disclosed which stabilizes impedance at laser drive initiation, and in which an oscillation at low current, a high reaction speed, a low noise, and the like are achieved. A semiconductor laser device includes first and second conductive type semiconductor layers, an active layer, and first and second electrodes. The second electrode comprises an ohmic electrode and a pad electrode. The first electrode is formed on the same planar side of the first conductive type semiconductor layer as the second electrode, and is disposed in the same direction as the pad electrode with respect to the ohmically connected region. The second conductive type semiconductor layer is set to a width that can secure light confinement on both sides of the ohmically connected region.
    Type: Grant
    Filed: August 4, 2004
    Date of Patent: August 14, 2007
    Assignee: Nichia Corporation
    Inventor: Akinori Yoneda
  • Patent number: 7257141
    Abstract: A phase array of oxide confined VCSELs and a method for forming the phase array of oxide confined VCSELs is described. VCSELs in the array are designed to be simultaneously addressed such that the output of multiple VCSELs can be used to increase the light intensity at a point. In applications where beam coherence from the VCSEL array is desirable, high gain coupling regions break the continuity of the oxide wall surrounding each VCSEL aperture. The high gain coupling regions connect adjacent VCSELs in the VCSEL array thereby allowing mode coupling between adjacent lasers and the output of a coherent beam of light.
    Type: Grant
    Filed: July 23, 2003
    Date of Patent: August 14, 2007
    Assignee: Palo Alto Research Center Incorporated
    Inventor: Christopher L. Chua
  • Patent number: 7257142
    Abstract: Semi-integrated external cavity diode laser (ECDL) designs including integrated structures comprising a gain section, phase control section, and optional modulator section. Each integrated structure includes a waveguide that passes through each of the sections. A mirror is defined in the structure to define one end of a laser cavity. A reflective element is disposed generally opposite a rear facet of the gain section, forming an external cavity therebetween. A tunable filter is disposed in the external cavity to effectuate tuning of the laser. During operation, a modulated drive signal is provided to the phase control section. This modulates an optical path length of the laser cavity, which produces an intensity (amplitude) modulation in the laser output. A detector is employed to produce a feedback signal indicative of the intensity modulation that is used for tuning the laser in accordance with a wavelength locking servo loop.
    Type: Grant
    Filed: March 29, 2004
    Date of Patent: August 14, 2007
    Assignee: Intel Corporation
    Inventors: Sergei L. Sochava, William B. Chapman, William J. Kozlovsky
  • Patent number: 7257143
    Abstract: Multi-component barrier layers include formation of a GaAs layer and at least one adjacent GaAsN layer. The resulting multi-component barrier layer shape can provide enhanced (extended) offset for capture of holes and enhanced electrons. Other benefits include: a small amount of strain compensation; poorer spatial overlap of higher confined states reducing parasitics at high bias, with some small effect on the lowest confined states. Quantum wells and associated barriers layers can be grown with combinations of gallium, (Ga), arsenic, (As), nitrogen (N), aluminum (Al), antimony (Sb), phosphorous (P) and/or indium (In) placed within or about a typical GaAs substrate to achieve long wavelength VCSEL performance, e.g., with wavelengths over 1200 nm. Layers of strained quantum well material can also be supported by mechanical stabilizers.
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: August 14, 2007
    Assignee: Finisar Corporation
    Inventor: Ralph H. Johnson
  • Patent number: 7257144
    Abstract: An excimer laser comprises a gas chamber, electrodes for creating rare gas/halide molecules that disassociate and produce optical emission, and reflective surfaces that form an optical resonant cavity. The excimer laser further comprises flow control surfaces that define gas flow paths and that control the flow of gas within the chamber. Preferably such flow control surfaces direct the gases away from the laser optics. More preferably, the flow control surfaces shield the path of the laser beam, at least in the proximity of the laser optics, from contaminants in the gases. Less contaminants yields less contamination of the laser optics. As a result, the laser device becomes more reliable and useful over longer periods of time. In addition, the laser gases are preferably exposed only to compatible materials that react with the laser gases to produce stable reaction products having a low vapor pressure, so as to reduce contamination of the gases and the optics.
    Type: Grant
    Filed: February 11, 2004
    Date of Patent: August 14, 2007
    Assignee: PhotoMedex
    Inventor: Jeffrey I. Levatter
  • Patent number: 7257145
    Abstract: A vacuum arc remelt furnace system that automatically monitors for electrode to crucible arcing in a VAR furnace. The vacuum arc remelt furnace system includes a crucible, an electrode provided within the crucible, and a spectrometer operatively coupled to the gap between the electrode and the crucible. The spectrometer detects the presence of one or more copper-specific light wavelengths in light that is present in the gap, and preferably generates an alarm and/or shuts the furnace down depending upon what is detected. Also, a method of operating a vacuum arc remelt furnace to automatically monitor for electrode top crucible arcing. The method includes collecting light that is present in the gap between the crucible and said electrode, and determining whether one or more copper-specific light wavelengths are present in the light. An alarm is generated and/or the furnace is shut down depending upon what is detected.
    Type: Grant
    Filed: June 2, 2005
    Date of Patent: August 14, 2007
    Assignee: Westinghouse Electric Co LLC
    Inventors: LaVar Ellis Griffin, Lonny Dean Severson
  • Patent number: 7257146
    Abstract: A method and system for stabilizing energy consumption in multiple loads, or in single multi-phase loads. The method and system also compensates for unbalance in multi-phase loads. A central controller monitors variable reactances in the loads and identifies situations of power and/or current fluctuation and/or unbalance. It determines appropriate corrective action by the other loads/phases to compensate for the power and/or current change or unbalance due to the problematic load, and it issues control signals instructing variable reactor controllers associated with the other loads to adjust accordingly. The method and system may by applied to electric arc furnace installations. The system and method may be employed to maintain a predetermined level of unbalance in the system.
    Type: Grant
    Filed: September 1, 2005
    Date of Patent: August 14, 2007
    Assignee: Hatch Ltd.
    Inventors: Mohammad Sedighy, Thomas Lai Wai Ma
  • Patent number: 7257147
    Abstract: A technique for receiving an error state in a single chip sequence in a wireless communications network is disclosed. The error state may comprise a Viterbi error state. The error state may be identified as a target code encoded in the single chip sequence, the target code comprising either a code or the complement of the code. The code may comprise a PN-Code. The error state may be identified using a previous mapping of error states from a set of error states to a group of codes, the group of codes comprising a plurality of codes and their complements. The error states in the set of error states in the previous mapping may be uniquely mapped to plurality of codes and their complements in the group of codes.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: August 14, 2007
    Assignee: Cypress Semiconductor Corporation
    Inventors: Robert W. E. Mack, Paul F. Beard
  • Patent number: 7257148
    Abstract: A spread code sequence generator generates a spread code sequence with the frequency of a synthesizer, and then outputs the spread code sequence to a multiplier. The multiplier outputs a spread signal obtained by multiplying a data sequence by the spread code sequence to an impulse generator. The impulse generator generates an impulse signal of very fine impulses that corresponds to 0s/1s of the spread signal. The impulse signal is outputted to a band pass filter, where a predetermined range of the impulse signal is extracted. The output of the band pass filter is fed to a subtracter and a delay circuit. The delay circuit delays the delayed signal by a predetermined period. The delayed signal is outputted to the subtracter. The subtracter subtracts the delayed signal from the output of the band pass filter. A signal obtained by such subtraction processing is transmitted as a transmission signal via an antenna.
    Type: Grant
    Filed: May 2, 2002
    Date of Patent: August 14, 2007
    Assignee: Sony Corporation
    Inventor: Mitsuhiro Suzuki
  • Patent number: 7257149
    Abstract: A code detector which may rapidly obtain initial code synchronization by generating different phases of a pseudo noise (PN) codes by a plurality of PN code generators. Also, the code detector implements multipliers in the code detector to perform simple and rapid multiplying operations of the output of the PN code generators.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: August 14, 2007
    Assignee: LG Electronics Inc.
    Inventor: Min-Ho Jin
  • Patent number: 7257150
    Abstract: An input signal is mixed with a scrambling code and with an OVSF code, and then accumulated over a period of time equal to one symbol of the pilot channel before being reset. The resultant complex signals are mixed with the conjugate of complex signals provided by a pilot pattern generator, with the result being fed to a delay line (22). A multiplier multiplies the complex value at a location P(n) in the delay line (22) by the conjugate of a complex value at another location P(n+k), and provides the resulting complex number (which is a complex vector whose phase is a coherent measurement of the phase rotation occurring between the symbols corresponding to the two locations) at an output (27). The real part of the complex signal provided at the output (27) is provided to a first combiner (30), and the imaginary part is provided to a second combiner (31). These combiners (30, 31) also receive corresponding signals from all of the other fingers (not shown) of the rake receiver.
    Type: Grant
    Filed: November 20, 2001
    Date of Patent: August 14, 2007
    Inventors: Diego Giancola, Andrew Thurston, Jonathan Lucas
  • Patent number: 7257151
    Abstract: A wireless device (10, 12) is provided that distinguishes between multiple piconets. The wireless device (10, 12) includes a preamble component (160, 162, 164, 166) and a correlator (150) component. The preamble component (160, 162, 164, 166) provides a preamble (120) for a wireless fixed frequency interleaving transmission, and the correlator component (150) distinguishes a wireless transmission based on the preamble (120). A circuit (180) is provided for a wireless receiver to despread a hierarchical sequence (120) made by spreading an M-length sequence (110) with an N-length sequence (112). The circuit (180) includes a first and second despreaders (185, 190). The first despreader (185) is coupled to a signal input to despread a received signal. The signal is a fixed frequency interleaved transmission. The second despreader (190) is coupled to an output of the first despreader (185). The second despreader (190) despreads the output of the first despreader (185) with a second sequence.
    Type: Grant
    Filed: December 23, 2004
    Date of Patent: August 14, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: Anuj Batra, Jaiganesh Balakrishnan
  • Patent number: 7257152
    Abstract: A method and apparatus for reducing the processing rate when performing chip-level equalization (CLE) in a code division multiple access (CDMA) receiver which includes an equalizer filter. Signals received by at least one antenna of the receiver are sampled at M times the chip rate. Each sample stream is split into M sample data streams at the chip rate. Multipath combining is preferably performed on each split sample data stream. The sample data streams are then combined into one combined sample data stream at the chip rate. The equalizer filter performs equalization on the combined sample stream at the chip rate. Filter coefficients are adjusted by adding a correction term to the filter coefficients utilized by the equalizer filter for a previous iteration.
    Type: Grant
    Filed: September 1, 2006
    Date of Patent: August 14, 2007
    Assignee: InterDigital Technology Corporation
    Inventor: Jung-Lin Pan
  • Patent number: 7257153
    Abstract: The invention relates to a method for synchronizing a receiver (1) with a transmitted code-modulated spread spectrum signal. The method uses at least one reference code (r(x)), which corresponds to a code used in the modulation. The frequency shift of the transmitted signal and the code phase of the code used in the modulation are determined in the method.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: August 14, 2007
    Assignee: Nokia Corporation
    Inventor: Ilkka Kontola
  • Patent number: 7257154
    Abstract: A high-speed bit stream interface module interfaces a high-speed communication media to a communication Application Specific Integrated Circuit (ASIC) via a Printed Circuit Board (PCB) or the communication ASIC to another communication ASIC. The high-speed bit stream interface includes a line side interface, a board side interface, and a plurality of signal conditioning circuits. The signal conditioning circuits service each of an RX path and a TX path and include a limiting amplifier and a clock and data recovery circuit. The signal conditioning circuit may also include an equalizer and/or an output pre-emphasis circuit. The clock and data recovery circuit has an adjustable Phase Locked Loop (PLL) bandwidth that is set to correspond to a jitter bandwidth of a serviced high-speed bit stream.
    Type: Grant
    Filed: July 23, 2003
    Date of Patent: August 14, 2007
    Assignee: Broadcom Corporation
    Inventor: Ali Ghiasi
  • Patent number: 7257155
    Abstract: The present invention provides a method for initialization and stepsize control of a time-domain equalizer (TEQ) in a receiver of a multi-carrier communication system to upgrade the performance of adaptive TEQ algorithms. As to TEQ initialization, the Time-domain Window Mask method generates a modified channel impulse response (CIR) by performing a locate maximum energy algorithm and then applies a time-domain window mask to adjust the modified CIR to obtain an initial value of a target impulse response. Then, a dividing operation is performed on the frequency-domain initial target impulse response and the modified CIR to determine an initial value of the frequency-domain TEQ impulse response. The Head-tail Equalizing method also performs the locate maximum energy algorithm, and the remaining points other than the consecutive points with maximum energy are combined and padded zero to the last few points to generate a modified CIR.
    Type: Grant
    Filed: February 20, 2004
    Date of Patent: August 14, 2007
    Assignee: Realtek Semiconductor Corp.
    Inventor: Fong-Ching Huang
  • Patent number: 7257156
    Abstract: An equalizer comprises a hard decision block which feeds an FEC block and a shift register, which uses past estimates during a first iteration. The output of the FEC block is fed back to the shift register during a subsequent iteration to fully remove any inter chip interference.
    Type: Grant
    Filed: September 23, 2004
    Date of Patent: August 14, 2007
    Assignee: Pulse˜Link, Inc.
    Inventor: Ismail Lakkis
  • Patent number: 7257157
    Abstract: Mode selection is optimized for video coding requiring sequencing of decisions with respect to a data block sequence. Each decision is selected from a mode set. The sequence is a directed acyclic dependency graph with depender blocks pointing to dependee blocks numbered in reverse topological order. A trellis state transition diagram is constructed from the reverse ordered graph. The least cost path through the trellis is determined to define the optimal decision modes selected from the set of modes at respective blocks. The number of trellis stages equals the number of decisions in the dependency graph from left to right. Each trellis stage has a varying number of states corresponding to cardinality of the mode set for the decision. The number of decisions to the left of a particular stage that the stage needs to remember equals the number of decisions to the right of the stage.
    Type: Grant
    Filed: September 25, 2002
    Date of Patent: August 14, 2007
    Assignee: Hewlett-Packard Development Company L.P.
    Inventor: Gene Cheung
  • Patent number: 7257158
    Abstract: A method of and apparatus for transmitting video images preferably allows a specially trained individual to remotely supervise, instruct, and observe administration of medical tests conducted at remote locations. This apparatus preferably includes a source device, a transmitting device, and at least one remote receiving device. Preferably, the transmitting device and the remote receiving device communicate over a network such as the Internet Protocol network. Alternatively, the transmitting device and the receiving device communicate over any appropriate data network. The transmitting device transmits the video images to the remote receiving device either for live display through the source device or for pre-recorded display through a video recorder device. The remote receiving device is also capable of communicating with the transmitting device while simultaneously receiving video images.
    Type: Grant
    Filed: May 17, 1999
    Date of Patent: August 14, 2007
    Inventors: Vincent Michael Figueredo, Kendyl Allan Roman, R. Paul Raposo, Richard Scott Neale, Cyrus Javad Hoomani, Thomas Joseph Broadbent
  • Patent number: 7257159
    Abstract: The bitrate control of known video encoders is based on a control of the quantization step size per picture block. In transform coding of relatively large picture blocks, the video picture comprises a too small number of picture blocks to obtain a desired number of bits per picture. In conformity with the invention, the target value for the number of bits per picture block is divided into N sub-targets (Rt(k,n)). The series of coefficients of a picture block is divided into N segments (L(n)) with reference to an estimation for the cumulative distribution 20 of the bit cost per picture block. The quantization step size is subsequently adapted per segment to the corresponding sub-target. Since the number of segments is N times larger than the number of picture blocks, an accurate bitrate control is possible. If desired, the estimation for the cumulative distribution is adapted from picture to picture.
    Type: Grant
    Filed: February 21, 1996
    Date of Patent: August 14, 2007
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Marcel Breeuwer, Reinier B. M. Klein Gunnewiek
  • Patent number: 7257160
    Abstract: A method and an apparatus of picture display. The invention displays the first picture and the second picture and displaying at least one virtual picture in between the first and the second picture. The motion compensator is included in a DVD player. The method includes: decoding the first and the second pictures from the received bit-stream; creating the virtual picture parameter according to the transition effect; and generating the virtual picture according to the virtual picture parameter by the motion compensator.
    Type: Grant
    Filed: January 17, 2003
    Date of Patent: August 14, 2007
    Assignee: Mediatek Inc.
    Inventors: Chi-Cheng Ju, Tzu-Ping Lin
  • Patent number: 7257161
    Abstract: An analyzer transforms a digital signal into a spectrum representing the digital signal. A spectrum analyzing unit specifies a predetermined number of sets of the bands in decreasing order of the correlation between the spectrum distributions from among the bands obtained by equally dividing the above spectrum into equal bands, and then specifies one of the two specified bands as a removed band and the other as a interpolation band. Then, a frequency shifting unit removes spectrum components within the removed bands and shifts spectrum components within another bands to the lower frequency side (that is, performs the thinning and compressing of frequency), and then supplies a signal representing the spectrum after thinning and compressing to a synthesizer. The synthesizer generates a signal represented by the spectrum after thinning and compressing.
    Type: Grant
    Filed: June 27, 2001
    Date of Patent: August 14, 2007
    Assignee: Kabushiki Kaisha Kenwood
    Inventor: Yasushi Sato
  • Patent number: 7257162
    Abstract: One method for analyzing a bitstream having a plurality of compressed pictures comprises computing an initial arrival time and a final arrival time of a compressed picture, wherein the initial arrival time is equal to an earlier of the final arrival time of the immediately previous compressed picture or equal to a sum of a fixed time plus a sum of removal delays of all of the compressed pictures between the first compressed picture following the buffering period message and the compressed picture, including the compressed picture, and wherein the final arrival time is equal a sum of the initial arrival time and a time calculated based on the number of bits associated with the compressed picture at the bit rate; and verifying that a difference between the final removal time and the initial arrival time does not exceed the time for reaching the buffer size at the bit rate.
    Type: Grant
    Filed: June 19, 2003
    Date of Patent: August 14, 2007
    Assignee: Conexant Systems, Inc.
    Inventors: Eric Viscito, Dzung T. Hoang
  • Patent number: 7257163
    Abstract: A system in which encoded data (e.g., encoded video and auxiliary data) are transmitted over a serial link. Other aspects of the invention are transmitters for use in encoding data for transmission over a serial link, receivers for receiving such data, and methods for sending encoded data over a serial link. Source data to be transmitted are encoded using a subset of a full set of code words. The subset consists of preferred code words. Disjoint clusters of code words in the full set are predetermined. Each cluster includes one or more of the preferred words, and optionally also at least one additional code word that is similar to a preferred word of the cluster in the sense that it is likely to be generated as a result of probable bit errors in transmission, or transmission and decoding, of such preferred word. Each preferred word of a cluster is indicative of a single source data value. Each received code word in a cluster is mapped to the source data value determined by each preferred word of the cluster.
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: August 14, 2007
    Assignee: Silicon Image, Inc.
    Inventors: Seung Ho Hwang, Jano Banks, Paul Daniel Wolf, Eric Lee, William Sheet, Albert M. Scalise
  • Patent number: 7257164
    Abstract: The present invention relates to Class-D amplifiers, and in particular to bit-flipping sigma-delta modulator (SDM) implementations of such amplifiers. Such amplifiers are particularly although not exclusively suitable for audio equipment such as hi-fi and personal music amplifiers. The present invention provides a bit flipping sigma delta modulator (BF SDM) having a multiple feedback loop filter structure. The modulator comprises a quantiser coupled to a bit flipping means, a look ahead quantiser to determine the next quantiser output, and a controller which determines whether to change the output of the bit flipping circuit. The modulator comprises a feedback loop arranged to add feedback from the output of the modulator to its input. The modulator comprises compensation circuit to adjust the states of the modulator in order to correct for bit flipping of the output of the quantiser. This adjusts the input to the quantiser to correspond to an input having feedback from a non bit flipped quantiser output.
    Type: Grant
    Filed: February 4, 2004
    Date of Patent: August 14, 2007
    Assignee: Wolfson Microelectronics plc
    Inventor: Anthony J. Magrath
  • Patent number: 7257165
    Abstract: A novel method and apparatus for preamble detection and time synchronization estimation in OFDM communication systems is described. The present invention can be easily implemented to provide preamble detection and highly accurate time synchronization estimations. The inventive method and apparatus utilizes phase and magnitude information obtained from a received signal to detect a preamble and to calculate a time synchronization estimation for the received signal.
    Type: Grant
    Filed: April 17, 2003
    Date of Patent: August 14, 2007
    Inventor: Steven H. Gardner
  • Patent number: 7257166
    Abstract: A data communication apparatus and method based on OFDMA are provided. In a first user transmitting unit through which a user transmits user information to a base station in units of first symbol blocks each including M symbols, a first encoder generates a first sub-block composed of Mu user symbols for a u-th user by encoding the user information. A first block repeater repeats the first sub-block Lu times to generate M symbols. A first multiplier multiplies the M symbols by ?u exp(j2?kmu/M) and outputs a u-th user signal. A first cyclic extension symbol inserter inserts a cyclic extension symbol into the u-th user signal and generates a single complete first symbol block. Accordingly, data transmission speed can be freely changed, a very small PAR can be provided, influence of the signal interference is greatly reduced, interference occurring between received blocks due to channels can be prevented, and distortion between channels can be effectively compensated for.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: August 14, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Yung-Soo Kim
  • Patent number: 7257167
    Abstract: Systems and methods of MIMO wireless communication system with partial feedback are disclosed. In one embodiment, a base station estimates the channel matrices of the K mobile units and transmits an index value corresponding to each of the estimated channel matrix. Each mobile unit selects a power control matrix and beam-forming matrix based on the received index value and transmits its data stream to the base station using the selected power control and beam-forming matrix. A method for generating the sets of power control matrices, beam-forming matrices, and partitions of the channel matrix space is disclosed.
    Type: Grant
    Filed: August 19, 2003
    Date of Patent: August 14, 2007
    Assignee: The University of Hong Kong
    Inventor: Kin Nang Lau
  • Patent number: 7257168
    Abstract: Systems, methods and apparatus are provided for equalizing a received multicarrier wireless telecommunications data signal. The wireless signal includes data without accompanying pilot signals, and equalization is accomplished by extracting information from the data, by processing the information in order to obtain equalization indications, and by equalizing the multicarrier wireless telecommunications data signal by modifying indications of the wireless telecommunications data signal using the equalization indications.
    Type: Grant
    Filed: August 12, 2003
    Date of Patent: August 14, 2007
    Assignee: PCTEL, Inc.
    Inventors: Yuri Goldstein, Yuri Okunev
  • Patent number: 7257169
    Abstract: A receiver for deserializing a stream of data bits, including a single clock which is adapted to generate a first plurality of clock phases, and a sample generator which is adapted to sample the stream so as to generate initial data values of each of the bits at times defined by the first plurality of clock phases. The receiver further includes digital circuitry which is adapted to group the initial values into a second plurality of sampling phase sets, according to the clock phases at which the values were sampled, and assign each of the phase sets a respective grade in response to at least some of the initial values. The circuitry selects a decoding phase set from the phase sets in response to the respective grades, and decodes the stream in response to initial values of the decoding phase set to generate decoded values of the consecutive bits.
    Type: Grant
    Filed: December 16, 2002
    Date of Patent: August 14, 2007
    Assignee: Mysticom Ltd.
    Inventors: Boaz Shahar, Eyran Lida, Eyal Massad
  • Patent number: 7257170
    Abstract: A channel norm-based ordering and whitened decoding technique (lower complexity iterative decoder) for MIMO communication systems performs approximately the same level of performance as an iterative minimum mean squared error decoder. Decoding a signal vector comprises receiving a signal vector yk, multiplying the received signal vector yk by a conjugate transpose of a channel matrix H*. A column vector zk is generated. The entries of the column vector zk are reordered and an estimated channel matrix {tilde over (H)} is generated. The estimated channel matrix {tilde over (H)} decomposed using a Cholesky decomposition and generating a triangular matrix L. Triangular matrix L is solved backwards and a signal vector {tilde over (s)}k estimated. An estimate of the transmitted symbol vector ?k is generated.
    Type: Grant
    Filed: August 20, 2003
    Date of Patent: August 14, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: David J. Love, Srinath Hosur, Anuj Batra, Tarik Muharemovic, Eko N. Onggosanusi
  • Patent number: 7257171
    Abstract: A system that includes a receiver (100) that is configured for: selecting (210) a set of demodulator output samples and a corresponding set of reference symbols; generating (220) a set of raw channel estimates based on the set of demodulator output samples and the corresponding set of reference symbols; subdividing (230) the set of raw channel estimates into a plurality of subsets; assigning and applying (240) a corresponding reference symbol magnitude quantization scheme to each subset; determining (250) a set of filter coefficients that is based on the quantization schemes applied to the subsets of raw channel estimates; and combining (260) the set of raw channel estimates with the set of filter coefficients to generate a channel estimate.
    Type: Grant
    Filed: April 4, 2005
    Date of Patent: August 14, 2007
    Assignee: Motorola, Inc.
    Inventors: Steven C. Jasper, Robert J. Corke, Colin D. Frank, Isam R. Makhlouf
  • Patent number: 7257172
    Abstract: A partial response (PR) waveform generator generates a digital value sequence of an expected PR waveform based on the output of a soft-decision Viterbi detector included in, for example, a first-stage decoder unit incorporated in an iterative decoder. The generator also generates flag information indicative of whether reliability of the digital value sequence is low or high, in parallel with the generation of the digital value sequence. An error detector detects error values in a PR equalized sample value sequence, needed for feedback control of a control target, using the digital value sequence of the expected PR waveform as a digital value sequence of a reference waveform. An error output controller controls the output of the error values detected by the error detector in accordance with the state of the flag information generated by the generator.
    Type: Grant
    Filed: October 6, 2003
    Date of Patent: August 14, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yutaka Okamoto, Manabu Akamatsu, Yuji Sakai
  • Patent number: 7257173
    Abstract: A description of signal behavior in the vicinity of a time and voltage of interest is produced by defining a region in the (time, voltage) plane that is a closed straight sided figure whose vertices are identified by threshold crossings offset for the voltage of interest and clocked by time delays offset from a clock time of interest. A first set of latches clocked by the time delays accumulates the state of signal behavior relative to the threshold voltages as it occurs, and their contents are subsequently transferred to a second set of latches at the start of a new clock cycle, allowing a new accumulation to begin and also allowing a detection logic circuit to operate on a unified and completed collection of indicators of what the just concluded description amounts to. The detection logic circuit responds to the combinations of latched indications to produce a signal corresponding to that description.
    Type: Grant
    Filed: April 28, 2004
    Date of Patent: August 14, 2007
    Assignee: Agilent Technologies, Inc.
    Inventors: Glenn Wood, David D. Eskeldson
  • Patent number: 7257174
    Abstract: A baseband digital signal block is processed at an output of a matched filter and at an input of a channel equalizer. This signal is fed to a whitening filter estimated for the block by taking into account interfering signals in the frequency band of the useful signal and in one or more adjacent bands. To this end, an autocorrelation vector, calculated form the block of received signal is projected onto different directions corresponding to predetermined correlation vectors relating to the useful signal, to signals which may be present in the adjacent bands and to the thermal noise. The coefficients of the whitening filter are then derived from the sum of the projected vectors, by taking into account the energy of the useful signal if the latter has not been cancelled prior to the computation of the autocorrelations.
    Type: Grant
    Filed: July 26, 2001
    Date of Patent: August 14, 2007
    Assignee: Nortel Networks Limited
    Inventors: Jean-Louis Dornstetter, Nidham Ben Rached
  • Patent number: 7257175
    Abstract: A method for detecting a periodic signal in a communication system. The method includes converting a time domain digitized signal to obtain a corresponding frequency domain digitized signal, quantizing at least two symbols of the frequency domain digitized signal to obtain quantization information, utilizing the quantization information to compute a detection metric for periodic signal detection, and determining that a periodic signal is detected if the detection metric is greater than a predetermined threshold.
    Type: Grant
    Filed: August 20, 2003
    Date of Patent: August 14, 2007
    Assignee: Afa Technologies, Inc.
    Inventors: Tsung-Liang Chen, Jen-Wei Liang
  • Patent number: 7257176
    Abstract: A method provides frequency and phase offset estimation in a SCDMA burst receiver (such as a DOCSIS 2.0 SCDMA burst receiver) by application of the known Least Square (LS) parameter estimation algorithm to a pre-known transmitted sequence, called preamble, in order to optimally characterize the phase and frequency offsets affecting the transmitted data. The LS parameter estimation algorithm is adapted to SCDMA burst receiver specifications by changing index calculations to fit according to SCDMA preamble locations. Improved estimation accuracy can be achieved by using weighted least squares that disregard symbols affected by impulse and burst noise. Weighted least squares can further impart more weight to last symbols to more accurately estimate contemporary impairments. The method is particularly useful for communication systems having large frequency and phase offsets as in the DOCSIS 2.0 SCDMA burst receiver.
    Type: Grant
    Filed: May 15, 2003
    Date of Patent: August 14, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: Naftali Sommer, Itay Lusky, Lior Ophir
  • Patent number: 7257177
    Abstract: A device and a method for determining a reference level for automatic gain control of a radio frequency signal to be received, particularly having a varying strength, in which method radio blocks are received on a logical general packet data traffic channel of a signal, which radio blocks have been transmitted with a predetermined transmission power level and by using a predetermined way of controlling the transmission power level. In the invention, said reference level is continuously determined on the basis of correctly received or valid radio blocks, wherein the reference level is corrected on the basis of the signal strength measured during the reception of each valid radio block.
    Type: Grant
    Filed: March 4, 2002
    Date of Patent: August 14, 2007
    Assignee: Nokia Corporation
    Inventor: Jari Ruohonen
  • Patent number: 7257178
    Abstract: A base band circuit of a receiver and a low cut-off frequency control means can quickly converge transition state due to gain fluctuation with setting a low cut-off frequency of a high-pass filter as low as possible. The base band circuit of a receiver has a variable amplifier variably amplifying a base band signal depending upon a gain control signal, a high-pass filter provided in a path of the base band signal, and a controller detecting variation magnitude of the gain control signal and controlling variation of a low cut-off frequency of the high-pass filter means depending upon the detected variation magnitude.
    Type: Grant
    Filed: January 14, 2003
    Date of Patent: August 14, 2007
    Assignee: NEC Corporation
    Inventor: Masaki Ichihara
  • Patent number: 7257179
    Abstract: A system and method for obtaining a frequency error estimate representing the difference between a reference frequency and the frequency of a space-time transmit diversity signal is disclosed herein. The method includes taking the correlation of total sums, comprised of partial sums taken in defined first and second intervals, to represent the frequency error as the imaginary component of the correlation function.
    Type: Grant
    Filed: March 6, 2002
    Date of Patent: August 14, 2007
    Assignee: Research In Motion Limited
    Inventors: Xin Jin, Runbo Fu, Jorgen S. Nielsen
  • Patent number: 7257180
    Abstract: During receiving of message signals, in particular radio signals, it is particularly important to free the receiving signal of interference, such as, e.g. noise or various kinds of interference. It would be desirable if the receiver had knowledge of the type of occurring interference in advance, before processing the received signal, in order therefore to be able to improve considerably signal processing, in particular equalisation and demodulation, of the receiving signal. A receiving method is here proposed, in which first the auto-correlation function of the spurious components contained in the received signal is estimated. Then the estimated auto-correlation function is compared with presettable sample functions and the sample auto-correlation function which most closely corresponds to the estimated auto-correlation function is chosen. Finally, by means of the selected sample function, further signal processing, in particular equalisation, of the received message signal is carried out.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: August 14, 2007
    Assignee: Alcatel
    Inventor: Romain Chizat
  • Patent number: 7257181
    Abstract: A method and apparatus is disclosed to overcome the effects of intersymbol interference during data transmission. Overcoming the effects of intersymbol interference makes possible higher data transmission rates for a given error rate. In one embodiment a receiver processing system a first, second and third filter, such that the second and third filter comprise feedback filters. Filter coefficients are calculated to reduce the undesirable effects of the channel, such as intersymbol interference. A training process occurs to establish the first filter as a mixed phase filter and the third filter as minimum phase filter. The second filter is configured based on the transfer function of the channel and one or more coefficients may be set to a predetermined value.
    Type: Grant
    Filed: May 24, 2004
    Date of Patent: August 14, 2007
    Assignee: Solarflare Communications, Inc.
    Inventors: William W. Jones, George A. Zimmerman
  • Patent number: 7257182
    Abstract: An ultra-wide band (UWB) radio frequency (RF) receiving device (205) includes a first receiver (305) that receives UWB RF signals, a second receiver (315) that receives an external cue, and a processing unit (330). The second receiver (315) receives an external cue that includes one of a television blanking signal, a zero-crossing of a FM radio transmission, a paging system signal, a zero-crossing of an analog voice transmission, a zero-crossing of an analog video transmission, a cellular telephony control channel signal, a cellular telephony traffic channel signal, a digital sub-band for an AM or FM radio station signal, a digital or analog signal in a short-wave-radio transmission, a digital television signal, a digital or analog signal in a land mobile radio transmission, a radio-navigation signal, a radar signal, a satellite signal, an acoustic event or signal, a magnetic event or signal, or an optical event or signal.
    Type: Grant
    Filed: October 21, 2002
    Date of Patent: August 14, 2007
    Assignee: BBN Technologies Corp.
    Inventors: Brig Barnum Elliott, Jerry D. Burchfiel
  • Patent number: 7257183
    Abstract: A clock recovery circuit includes a sampler for sampling a data signal. Logic determines whether a data edge lags or precedes a clock edge which drives the sampler, and provides early and late indications. A filter filters the early and late indications, and a phase controller adjusts the phase of the clock based on the filtered indications. Based on the filtered indications, a frequency estimator estimates the frequency difference between the data and clock, providing an input to the phase controller to further adjust the phase so as to continually correct for the frequency difference.
    Type: Grant
    Filed: June 21, 2002
    Date of Patent: August 14, 2007
    Assignee: Rambus Inc.
    Inventors: William J. Dally, John H. Edmondson, Ramin Farjad-Rad
  • Patent number: 7257184
    Abstract: A phase comparator comprises a latch unit for latching the input data signal in parallel on rising/falling edges of the respective clock signals respectively, an error signal output unit for outputting m error signals respectively indicative of differences in phase between the transient edge of the input data signal and the transient edges of the respective clock signals and each having a minimum pulse width of (m/2?1)×T or more, based on respective output signals produced from the latch unit and the respective clock signals, an input unit for inputting the respective output signals produced from the latch unit in parallel on the rising/falling edges of the respective clock signals and a reference signal output unit for outputting m reference signals whose pulse widths are (m/2)×T, based on output signals produced from the input unit and the respective clock signals.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: August 14, 2007
    Assignee: NTT Electronics Corporation
    Inventor: Yusuke Otomo
  • Patent number: 7257185
    Abstract: A fuel assembly includes a bottom nozzle set on a lower core plate of a nuclear reactor, a top nozzle with a hold down spring to urge the bottom nozzle against the lower core plate, guide thimbles which guide control rods, having passed through the top nozzle, toward the lower core plate, a dashpot formed on each of the guide thimbles to reduce the fall velocity of a corresponding one of the control rods, a thimble screw which connects each of the guide thimbles to the bottom nozzle, and a drain hole formed to extend through each of the thimble screw. The dashpot has a large-diameter portion with substantially the same diameter as that of each of the guide thimbles. The diameter d of the drain hole falls within a range of 0.04 D<d<0.08 D where D is an inner diameter of the large-diameter portion.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: August 14, 2007
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Masahiko Yamada, Koichi Nunokawa
  • Patent number: 7257186
    Abstract: An imaging method is disclosed for a multi-slice spiral CT scan. A CT unit is disclosed for carrying out this method. In the method, the filtering may be formed by use of multiple applications of a ramp filter and a masking operation to a projection image in a different sequence. The CT unit may include, for filtering purposes, multiple applications of a ramp filter and a masking operation to a projection image in a different sequence.
    Type: Grant
    Filed: October 17, 2003
    Date of Patent: August 14, 2007
    Assignee: Siemens Aktiengesellschaft
    Inventors: Herbert Bruder, Guenter Lauritsch, Karl Stierstorfer, Kwok Tam