Having Correlation-type Receiver Patents (Class 375/142)
  • Patent number: 8811453
    Abstract: An intermediate symbol buffer (ISB) configuration and method is provided such that the ISB memory comprises 15 portions, one for each HSDPA spreading code. Symbols associated with a spreading code are written to the memory portion associated with the same spreading code. When a covariance calculation is performed to obtain a more accurate channel estimate, only the symbols associated with spreading codes determined to be needed for the covariance calculation are written to the ISB by a buffer block and red from the ISB by a correlation core. The symbols associated with spreading codes that are not necessary for a covariance calculation may be masked from being written or read from the ISB. In some embodiments each memory portion is an individual memory block. In other embodiments a plurality of memory blocks may contain a plurality of memory portions, one memory partition designated, at least temporarily, for each spreading code.
    Type: Grant
    Filed: September 22, 2011
    Date of Patent: August 19, 2014
    Assignee: Ericsson Modems SA
    Inventors: Ricky Nas, Cornelis Van Berkel, Jean-Paul Smeets
  • Patent number: 8811454
    Abstract: Provided are a method for dynamically acquiring a PN synchronization of a blink signal in a reader according to a channel state when a tag transmits a direct sequence spread spectrum (DSSS) blink signal having a predetermined period and the reader receives the blink signal in a 2.4 GHz RTLS system which complies with an ISO/IEC24730-2 standard, and a method for synchronizing a frame using a preamble.
    Type: Grant
    Filed: June 26, 2012
    Date of Patent: August 19, 2014
    Assignee: LSIS Co., Ltd.
    Inventor: Jae Wook Kim
  • Patent number: 8804790
    Abstract: A method for communicating comprises generating at least one generalized Golay code from a concatenation of constituent Golay codes, and spreading at least a portion of a data stream with the at least one generalized Golay code. Generalized Golay codes comprise pseudo-complementary sequences having code lengths that differ from Golay complementary sequences and are characterized by low autocorrelation sidelobes relative to the autocorrelation peak.
    Type: Grant
    Filed: April 26, 2009
    Date of Patent: August 12, 2014
    Assignee: Adeptence, LLC
    Inventor: Ismail Lakkis
  • Patent number: 8804789
    Abstract: A configurable multimode despreader for spread spectrum applications is disclosed herein. The despreader includes a plurality of data lines, at least one selective coupler coupled to the plurality of data lines, at least one multiplier coupled to the selective coupler, and a code input line coupled to the multiplier. The selective coupler selectively couples one of the plurality of data lines with the multiplier per any one of a plurality of despreading protocols. The multiplier then multiplies a desired input data type received from the selective coupler with a despreading code chip received from the code input line to produce an observation. The programmable multimode despreader supports variable code and data modulation schemes and variable spreading factors.
    Type: Grant
    Filed: July 11, 2005
    Date of Patent: August 12, 2014
    Assignee: Infineon Technologies AG
    Inventor: Ravi Subramanian
  • Patent number: 8798210
    Abstract: Methods, system and apparatuses for carrier frequency offset estimation are disclosed. The method includes: receiving a preamble sequence rn with a correlator and correlating the preamble sequence with a locally stored Barker code bn to obtain a correlation result cn; extracting peak values from every L points in cn to form a peak value sequence xn, L being a length of a Barker code that corresponds to the sampling rate; performing frequency offset estimation to xn by using at least two frequency offset estimation apparatuses, the at least two frequency offset estimation apparatuses adopting different delay parameters D; and inputting the results output from the at least two frequency offset estimation apparatuses into a frequency offset combination module to calculate a final carrier frequency offset estimate, whereby accurate frequency estimation can be achieved and an appropriate acquisition range of frequency offset can be ensured.
    Type: Grant
    Filed: August 28, 2012
    Date of Patent: August 5, 2014
    Assignee: Omnivision Technologies (Shanghai) Co., Ltd.
    Inventor: Yun Zhang
  • Patent number: 8798125
    Abstract: The present invention includes a method of determining a phase estimate for an input signal having pilot symbols. The method includes receiving a plurality of pilot symbols, and then multiplying two or more pilot symbol slots by corresponding correlator coefficients to correct a phase estimate of the input signal.
    Type: Grant
    Filed: August 5, 2013
    Date of Patent: August 5, 2014
    Assignee: Broadcom Corporation
    Inventors: Tommy Yu, Amy Gayle Hundhausen
  • Patent number: 8787426
    Abstract: In a receive node of a wireless network, an iterative multi-user multi-stage interference cancellation receiver is used. After each stage of interference cancellation, interference characteristics change. An adaptive finger placement strategy is used in which after each stage of interference cancellation, finger delays and combining weights of the receiver are adapted to reflect the changed interference characteristics.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: July 22, 2014
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Yi-Pin Eric Wang, Stephen Grant, Ning He, Niklas Johansson
  • Patent number: 8787505
    Abstract: A system including a differential demodulation module that generates differentially demodulated signals based on having differentially demodulated received signals. A first summing module generates a combined signal, including a plurality of symbols, by adding the differentially demodulated signals. A second summing module generates a plurality of sums for each of a plurality of derived preamble sequences, which are derived from preamble sequences. Each of the derived preamble sequences includes a plurality of derived symbols. One of the plurality of sums generated for one of the derived preamble sequences is a sum of a first portion of one of the plurality of symbols of the combined signal and a second portion of one of the derived symbols of the one of the derived preamble sequences.
    Type: Grant
    Filed: October 29, 2013
    Date of Patent: July 22, 2014
    Assignee: Marvell International Ltd.
    Inventors: Jungwon Lee, Hui-Ling Lou
  • Patent number: 8780955
    Abstract: A signal processing apparatus which calculates a correlation value between an input analog signal and a digital code includes: an adder which adds a noise signal to the analog signal; an analog comparator which compares, synchronously with a clock signal having a first period, a magnitude of the analog signal added with the noise signal with a reference voltage; a multiplier which receives an input of a comparison result from the analog comparator and the digital code and calculates, synchronously with the clock signal, an exclusive OR between the comparison result and the digital code; and a counter which accumulates calculation results from the multiplier over a second period in a time series, and calculates, as the correlation value, a difference between an accumulation result and one-half of a quotient of the second period and the first period.
    Type: Grant
    Filed: September 25, 2013
    Date of Patent: July 15, 2014
    Assignee: Panasonic Corporation
    Inventor: Takeshi Fukuda
  • Patent number: 8767796
    Abstract: Methods and systems consistent with this invention receive a plurality of transmitted signals in a receiver having a plurality of receive elements, wherein each transmitted signal has a different spatial location. Such methods and systems receive the plurality of transmitted signals at the plurality of receive elements to form a plurality of receive element signals, form a combined signal derived from the plurality of receive element signals, and detect each of the plurality of transmitted signals from the combined signal by its different spatial location. To achieve this, methods and systems consistent with this invention generate a plurality of arbitrary phase modulation signals, and phase modulate each of the plurality of receive element signals with a different one of the phase modulation signals to form a plurality of phase modulated signals.
    Type: Grant
    Filed: February 24, 2009
    Date of Patent: July 1, 2014
    Assignee: Greenwich Technologies Associates
    Inventor: Carl M. Elam
  • Patent number: 8768570
    Abstract: A wheel suspension system for a three-wheeled motorcycle or “trike” includes parallel wheels mounted on vertically pivoting suspension arms governed by hydraulic pistons. The pistons have upper liquid reservoirs that are interconnected through a valve system, which interconnects the upper reservoirs when the trike is in motion, allowing opposing vertical wheel movements when banking through turns, and prevents liquid exchange when the trike is stopped, thereby holding the motorcycle upright, Embodiments include a manual and/or automatic valve control. A threshold switching speed for an automatic controller can be factory set and/or user adjustable. The pistons can include directly interconnected lower fluid reservoirs. A shock-absorbing reservoir can allow transient vertical movement of both wheels to absorb shocks. A cover system can emulate the appearance of saddle bags and can appear to be covering only a single wheel.
    Type: Grant
    Filed: August 7, 2013
    Date of Patent: July 1, 2014
    Inventor: Steven P Young
  • Patent number: 8761299
    Abstract: A preamble generating apparatus used for synchronization of a reception apparatus in an orthogonal frequency division multiplexing system and generating a preamble to be added to a beginning of data at a time of communication, receives preamble length identifying information and position specifying information, and generates a plurality of elements constituting a preamble according to a predetermined sequence based on those information. The preamble generating apparatus creates a preamble model, and generates a plurality of preambles by setting the generated elements at positions of elements in element deciding information included in the preamble model, the positions indicating elements in the preamble model which are to be used in data communication.
    Type: Grant
    Filed: July 27, 2011
    Date of Patent: June 24, 2014
    Assignee: Icom Incorporated
    Inventor: Nobuyoshi Nishikawa
  • Patent number: 8761323
    Abstract: In a receive node of a wireless network, an iterative multi-user multi-stage interference cancellation receiver is used. After each stage of interference cancellation, interference characteristics change. An adaptive strategy is used in which after each stage of interference cancellation, impairment covariance is parametrically updated and combining weights of the receiver are adapted to reflect the updated impairment covariance.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: June 24, 2014
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Yi-Pin Eric Wang, Gregory Bottomley, Jung-Fu Cheng, Stephen Grant, Ning He, Niklas Johansson, Cagatay Konuskan
  • Patent number: 8743843
    Abstract: Wireless terminal beacon signaling is used to achieve timing synchronization between two wireless terminals in a wireless communication system, e.g., in an ad hoc network lacking a centralized timing reference. An exemplary timing structure used by an individual wireless terminal includes a beacon transmission time interval, a beacon monitoring time interval and a silence time interval. A first wireless terminal monitoring for beacon signals from other wireless terminals, detects a beacon signal portion from a second wireless terminal and determines a timing adjustment as a function of the detected beacon signal portion. The first wireless terminal applies the determined timing adjustment, e.g., time shifting its timing structure, such that its beacon signal can be detected by the second wireless terminal.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: June 3, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Rajiv Laroia, Sundeep Rangan, Arnab Das, Frank A. Lane, Junyi Li
  • Patent number: 8731029
    Abstract: Systems and techniques relating to wireless communications are described. A described technique includes receiving information that is indicative of a wireless communication signal transmitted by a wireless communication device, the wireless communication signal having been generated based on a spreading sequence and a known preamble; determining, based on the received information and the known preamble, an estimation of a first frequency offset using two or more locations for encoding elements associated with the spreading sequence; determining, based on the received information, the known preamble, and the first frequency offset, an estimation of a second frequency offset using two or more locations for symbols associated with the known preamble, the second frequency offset being different from the first frequency offset; and processing the received information based on a combination of the first frequency offset and the second frequency offset.
    Type: Grant
    Filed: January 11, 2011
    Date of Patent: May 20, 2014
    Assignee: Marvell International Ltd.
    Inventors: Songping Wu, Quan Zhou, Daxiao Yu
  • Patent number: 8731110
    Abstract: A GPS receiver includes an RF section and a digital section, the digital section including a correlator circuit for performing correlation with respect to a plurality of satellite channels. The GPS receiver is operated by cycling power to the RF section on and off according to a determined duty cycle having an ON portion and an OFF portion. During the ON portion, navigation related data received from the plurality of satellite channels is sampled by higher level software. Continuity of function may be achieved by resetting a state of at least a portion of the correlator circuit in correspondence to a transition from the OFF portion to the ON portion.
    Type: Grant
    Filed: February 22, 2011
    Date of Patent: May 20, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Hao Zhou, Aku-Matti T. Levola
  • Publication number: 20140133522
    Abstract: In an ultra-wideband (“UWB”) receiver, a received UWB signal is periodically digitized as a series of ternary samples. The samples are continuously correlated with a predetermined preamble sequence to develop a correlation value. When the value exceeds a predetermined threshold, indicating that the preamble sequence is being received, estimates of the channel impulse response (“CIR”) are developed. When a start-of-frame delimiter (“SFD”) is detected, the best CIR estimate is provided to a channel matched filter (“CMF”) substantially to filter channel-injected noise.
    Type: Application
    Filed: January 16, 2014
    Publication date: May 15, 2014
    Applicant: DECAWAVE LIMITED
    Inventors: Michael McLaughlin, Ciaran McElroy, Sinbad Wilmot, Tony Proudfoot
  • Patent number: 8724675
    Abstract: A method for detecting coherent interference includes the steps of: (a) receiving a signal at a first frequency, (b) forming a set of cross-correlation results by at least cross-correlating the signal with a first known code for a plurality of code offsets, (c) determining a statistical signature of the cross-correlation results, and (d) deciding, based on the statistical signature, whether non-negligible coherent interference is present within a search bin defined by the combination of the first frequency and the first known code.
    Type: Grant
    Filed: February 6, 2012
    Date of Patent: May 13, 2014
    Assignee: Cambridge Silicon Radio Limited
    Inventors: Murray Robert Jarvis, Gary Lennen
  • Patent number: 8724677
    Abstract: Provided are a method and apparatus (receiver) of receiving and processing a radio signal in a transmitter-receiver environment. The radio signals are transmitted across a wireless interface using Ultra Wideband (UWB) pulses. A transmitted reference approach is utilized. The radio signal include pairs of UWB pulses with each pair of pulses separated by a fixed time delay. The two pulses are then combined to provide for improved noise immunity.
    Type: Grant
    Filed: October 17, 2013
    Date of Patent: May 13, 2014
    Assignee: University of South Florida
    Inventor: James L. Tucker
  • Patent number: 8718115
    Abstract: Systems and methods for building, transmitting, and receiving frame structures in power line communications (PLC) are described. Various techniques described herein provide a preamble design using one or more symbols based on a chirp signal that yields a low peak-to-average power ratio (PAPR). According to some techniques, the preamble may be constructed with one or more different types and/or number of symbols configured to identify a PLC domain operating in close physical proximity to another PLC domain. According to other techniques, one or more preamble symbols may be interspersed within a header portion of a PLC frame to facilitate estimation of a frame boundary and/or sampling frequency offset, for example, in the presence of impulsive noise. According to yet other techniques, a PLC detector may be capable of receiving and decoding two or more types of PLC frames (e.g., using different PLC standards).
    Type: Grant
    Filed: October 10, 2011
    Date of Patent: May 6, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Anand G. Dabak, Badri N. Varadarajan, Il Han Kim, Tarkesh Pande
  • Patent number: 8711827
    Abstract: A mobile terminal having a receive diversity function using a plurality of receive antennas, having a calculation section which combines respective level measurement results of the receive antennas and calculates a level measurement value after being combined as the level measurement result of the mobile terminal.
    Type: Grant
    Filed: November 28, 2007
    Date of Patent: April 29, 2014
    Assignee: Fujitsu Limited
    Inventors: Syuuichi Murata, Takaharu Nakamura
  • Patent number: 8711902
    Abstract: In a synchronization processing circuit in a wireless communication system, a correlation operation unit is designed to have a parallel structure which can be restructured to improve flexibility in order to cope with various synchronization processings in a plurality of radio systems. The synchronization processing circuit in the wireless communication system comprises a plurality of correlation operation modules 31 through 3N that execute correlation operation, each of which correlation operation modules includes a plurality of correlators 60, a plurality of shift registers 50 for shifting a correlation code, an interface which transfers a shifted correlation code to an adjacent correlation operation unit for timing correlation processing, and a correlation code selection unit 40 which selects an externally and individually applied correlation code for code correlation processing and a correlation code transferred from an adjacent correlation operation unit as the correlation code.
    Type: Grant
    Filed: December 21, 2009
    Date of Patent: April 29, 2014
    Assignee: NEC Corporation
    Inventor: Toshiki Takeuchi
  • Patent number: 8705661
    Abstract: A method for performing channel estimation in a millimeter wave wireless communication system. The method includes receiving complementary sequences at a receiver of the millimeter wave wireless communication system. The received complementary sequences are generated at a first sampling rate; producing special complementary sequences from the received complementary sequences; cross-correlating the special complementary sequences with an input signal related to the received complementary sequences. The cross-correlation is performed at a second sampling rate and the second sampling rate is higher than the first sampling rate; and analyzing the result of the cross-correlation to estimate at least characteristics of a channel between the receiver and a transmitter of the millimeter wave wireless communication system.
    Type: Grant
    Filed: February 29, 2012
    Date of Patent: April 22, 2014
    Assignee: Wilocity, Ltd.
    Inventors: Amichai Sanderovich, Ohad Rozen
  • Patent number: 8699638
    Abstract: The present invention discloses a method for implementing automatic frequency control, and an apparatus thereof. The method discloses: calculating a correlation value of common pilot symbols in a reception signal of each path and a frequency offset value, calculating a combined frequency offset value according to the frequency offset value of each path, and determining, according to the combined frequency offset value, a frequency offset adjustment value for a voltage controlled oscillator, a frequency offset adjustment value for overall reception signals and a frequency offset adjustment value for the reception signal of each path. The present invention selects a method of small-scope frequency offset estimation, which makes frequency offset estimation more accurate.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: April 15, 2014
    Assignee: ZTE Corporation
    Inventor: Liqiang Yi
  • Patent number: 8693524
    Abstract: A synchronization method for impulse system ultra-wideband takes frame as basic unit for data transmission, each frame is divided into a preamble symbol part and a data part, wherein the preamble symbol part sends a known impulse sequence for channel estimation and synchronization; the data part takes the information to be transmitted; the preamble symbol part is divided into two parts of a positive and negative impulse sequence, which includes odd impulses with alternant positive and negative polarities, and a same direction impulse sequence, which is composed of impulses with same polarity and is the same as the polarity of the last impulse in the positive and negative impulse sequence. The method provides such advantages as high synchronization precision, small storage space, and capability of immediately finding out the synchronization position etc., and provides an important value for the development of the impulse system ultra-wideband wireless communication technique.
    Type: Grant
    Filed: September 28, 2009
    Date of Patent: April 8, 2014
    Assignee: Southeast University
    Inventors: Zaichen Zhang, Liang Wu, Xutao Yu, Guangguo Bi, Xiaohu You
  • Patent number: 8693526
    Abstract: This invention teaches a way to multiplex and de-multiplex unipolar signals using spread spectrum methods. While bipolar spread spectrum signal multiplexing may be used in may applications, for example for systems using radio signals, when using unipolar signals there is a loss of orthogonally which makes the standard algorithms unworkable. This invention teaches a method to recover orthogonally and make spread spectrum multiplexing useful for unipolar signals. One example is in the measurement of optical absorbance along multiple paths simultaneously using light signals, as for functional near infrared spectroscopy (fNIRS).
    Type: Grant
    Filed: February 16, 2012
    Date of Patent: April 8, 2014
    Inventor: Chester Roy Wildey
  • Patent number: 8687674
    Abstract: A surface acoustic wave (SAW) correlator spread-spectrum (SS) receiver is disclosed which utilizes a first demodulation stage with a chip length n and a second demodulation stage with a chip length m to decode a transmitted SS signal having a code length l=n×m which can be very long (e.g. up to 2000 chips or more). The first demodulation stage utilizes a pair of SAW correlators which demodulate the SS signal to generate an appropriate code sequence at an intermediate frequency which can then be fed into the second demodulation stage which can be formed from another SAW correlator, or by a digital correlator. A compound SAW correlator comprising two input transducers and a single output transducer is also disclosed which can be used to form the SAW correlator SS receiver, or for use in processing long code length signals.
    Type: Grant
    Filed: October 6, 2005
    Date of Patent: April 1, 2014
    Assignee: Sandia Corporation
    Inventor: Robert W. Brocato
  • Patent number: 8681911
    Abstract: Provided is an identification signal analyzing apparatus and method for compensating power of a channel profile occurring at a conventional identification signal analyzing apparatus by using a power compensation. The identification signal analyzing apparatus includes: an identification signal generator for generating an identification signal identical to a known identification signal inserted by a transmission device; a partial correlator for calculating a correlation value between a received signal including the known identification signal inserted by the transmission device and the identification signal generated by the identification signal generator through a partial correlation; a power compensator for compensating power of the correlation value calculated by the partial correlator; and a channel profile extractor for extracting a channel profile from the correlation value compensated by the power compensator.
    Type: Grant
    Filed: May 15, 2008
    Date of Patent: March 25, 2014
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Jae-Young Lee, Sung-Ik Park, Ho-Min Eum, Jae-Hyun Seo, Heung-Mook Kim, Jong-Soo Lim, Soo-In Lee
  • Patent number: 8681834
    Abstract: A wireless communication system. The system comprises transmitter circuitry (BST1), the transmitter circuitry comprising encoder circuitry (50) for transmitting a plurality of frames (FR). Each of the plurality of frames comprises a primary synchronization code (PCS) and a second synchronization code (SSC). The encoder circuitry comprises of circuitry (501) for providing the primary synchronization code in response to a first sequence (32). The encoder circuitry further comprises circuitry (502) for providing the secondary synchronization code in response to a second sequence (54) and a third sequence (56). The second sequence is selected from a plurality of sequences. Each of the plurality of sequences is orthogonal with respect to all other sequences. The third sequence is a subset of bits from the first sequence.
    Type: Grant
    Filed: February 23, 2012
    Date of Patent: March 25, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Anand G. Dabak, Sundararajan Sriram, Srinath Hosur
  • Patent number: 8675788
    Abstract: A method of estimating frequency offset of a received signal in a terminal apparatus comprises a) determining a phase change between a first and a second reference symbol of the received signal, wherein the time distance t between the first and the second reference symbols is associated with an observation frequency f such that f=1/t. The method further comprises: b) determining a preliminary frequency offset ?f based on the determined phase change, wherein ?f forms a frequency offset hypothesis ?fh; and c) decoding at least a part of the received signal, with application of the frequency offset hypothesis ?fh, to a decoded signal. The method further comprises: d) determining whether the decoded signal is a successful decoding.
    Type: Grant
    Filed: February 22, 2010
    Date of Patent: March 18, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Niklas Andgart, Peter Alriksson, Joakim Axmon, Bengt Lindoff, George Jöngren
  • Patent number: 8676137
    Abstract: A mobile wireless terminal includes a wireless receiving part configured to receive a wireless signal from a base station which belongs to a mobile communication system using a time-frequency conversion for baseband processing; a received signal processing part that includes a time-frequency converting circuit and is configured to process the wireless signal; a setting part configured to successively set central frequencies within regions, wherein a frequency band that the mobile communication system uses is divided into the regions having a predetermined bandwidth; and a received signal strength measuring part configured to measure signal strength of received signals over the regions of the frequency band that the mobile communication system uses based on time-frequency conversion results from the time-frequency converting circuit, the time-frequency conversion results being obtained for the respective regions using the respective central frequencies set by the setting part.
    Type: Grant
    Filed: January 20, 2012
    Date of Patent: March 18, 2014
    Assignee: Fujitsu Mobile Communications Limited
    Inventor: Yoshiyuki Kubo
  • Publication number: 20140064338
    Abstract: In one embodiment, a programmable vector processor performs preamble detection in a wireless communication network. Implementation of preamble detection in the vector processor is made possible by a set of vector instructions that include (i) a circular load instruction for loading vectors of received data, (ii) a correlation instruction for correlating the vectors of received data with vectors of the scrambling code to concurrently generate a plurality of complex correlations, (iii) a partial-transpose instruction for arranging vectors of the complex correlations for use by a Fast Hadamard Transform (FHT) processor, and (iv) an FHT instruction for performing FHT processing on a vector of complex correlations. Implementing preamble detection in the vector processor allows more of the received data to be processed concurrently. As a result, preamble detectors of the disclosure may detect preambles using fewer clock cycles than that of comparable preamble detectors implemented using hardware accelerators.
    Type: Application
    Filed: March 13, 2013
    Publication date: March 6, 2014
    Applicant: LSI Corporation
    Inventors: Meng-Lin Yu, Jian-Guo Chen, Alexander Alexandrovich Petyushko, Ivan Leonidovich Mazurenko
  • Patent number: 8660166
    Abstract: Method and receiver synchronizing receiver with received ambiguous signal having at least two peaks. Method includes providing information about known transmitted signal having a number of at least two peaks, the information including number of peaks and distances between at least two peaks, determining ratios between peaks of known transmitted signal and assigning determined ratio value to each peak, and deducing theoretical auto-correlation function from known transmitted signal. Auto-correlation function has number of correlations corresponding to number of peaks in known transmitted signal and correlators of the auto-correlation function are provided in same distance and have the same relative ratio as peaks in known transmitted signal.
    Type: Grant
    Filed: December 6, 2011
    Date of Patent: February 25, 2014
    Assignee: Astrium GmbH
    Inventors: Jean-Jacques Floch, Francis Soualle
  • Patent number: 8660165
    Abstract: An apparatus for detecting a spread spectrum signal in a wireless signal environment includes at least one antenna for receiving spread spectrum signals, such as UMTS signals, from a signal source in the wireless signal environment. In one embodiment, a detection circuit is configured for correlating a code in signal received by the apparatus with a set of possible codes for spread spectrum signals in order to detect the existence of a spread spectrum signal. In another embodiment, a detection circuit is configured for obtaining at least one reference frame of data from a received signal. The detection circuit is further operable for correlating a segment of the reference frame with a repeated segment of at least one subsequent frame of data in order to detect the existence of a spread spectrum signal. A repeater might incorporate such an apparatus wherein the variable gain of the repeater is adjusted based upon the correlation and the detection of a spread spectrum signal.
    Type: Grant
    Filed: June 11, 2009
    Date of Patent: February 25, 2014
    Assignee: Andrew LLC
    Inventors: Ariful Hannan, John Carlson
  • Patent number: 8644265
    Abstract: Multipoint broadcasting requires that the downlink-channel information be available at collaborating base stations. Methods and apparatus for wideband analog channel feedback are described that provide downlink-channel information feedback from mobile users to base stations via uplink channels, and that use very few or no resources of the RAT of the wireless cellular network. Also described are methods and apparatus that perform channel-feedback signal cancellation at base stations to reduce its interference on the uplink-traffic signal. Wideband analog channel feedback is adaptable to the feedback bandwidth in uplink, and it offers frequency diversity to combat the deep fading in feedback channels. Wideband analog channel feedback is also applicable to uplink channel-information feedback. Applications of the described methods and apparatus include multipoint broadcasting in a wireless cellular network, and more generally, channel feedback between two communicating devices in a communications network.
    Type: Grant
    Filed: September 30, 2011
    Date of Patent: February 4, 2014
    Inventor: Xiao-an Wang
  • Patent number: 8644364
    Abstract: A mobile device receives downlink transmissions comprising replicas of an original downlink transmitted signal over corresponding fingers of a RAKE receiver comprising arithmetic units. The RAKE receiver computes a cell normalization factor for each of active cells and neighbor cells associated with the RAKE receiver. The RAKE receiver uses the same arithmetic units comprising one adder, one multiplier, one divider and/or one square root unit to compute cell normalization factors. The received downlink transmitted signal is processed using the computed cell normalization factors. The RAKE receiver determines signal power from each of other cells, separately, to compute cell normalization factors to normalize fingers of the RAKE receiver. Interference over the normalized fingers are cancelled and used to process the received downlink transmitted signal, which are combined and Turbo decoded.
    Type: Grant
    Filed: November 11, 2009
    Date of Patent: February 4, 2014
    Assignee: Broadcom Corporation
    Inventor: Thirunathan Sutharsan
  • Patent number: 8638888
    Abstract: One embodiment of the present invention relates to an analog correlation unit comprising a plurality of parallel correlation components configured to operating according to an advanced switched-capacitor low pass filter principle that increases coding gain of the unit. Each correlation component comprises a sampling stage and a correlation stage. The sampling stage may comprise a switched capacitor configured to sample a received baseband signal to determine a value (e.g., polarity) of the baseband signal. The sampled baseband signal is provided to the correlation stages, which may respectively comprise a plurality of switched integrators configured to selectively receive and integrate the sampled baseband signal over time depending upon values (e.g., polarity) of the correlation code to generate voltage potential values. The analog correlation result is evaluated by a comparison of an adjustable threshold voltage with the difference between the output voltage potential values.
    Type: Grant
    Filed: July 21, 2011
    Date of Patent: January 28, 2014
    Assignee: Infineon Technologies AG
    Inventors: Christian Hambeck, Stefan Mahlknecht, Thomas Herndl, Franz Darrer, Jakob Jongsma
  • Patent number: 8634490
    Abstract: A receiver of a multiple-input multiple-output (MIMO) system performs QR decomposition of the channel matrix to enable detection of a transmitted vector in a layered manner. In each layer, a sub-vector of the transmitted vector is estimated. A reactive tabu search is performed if an estimated symbol differs from a nearest symbol in the alphabet by a predetermined value. The receiver may order the entries of the channel matrix prior to QR decomposition to enable estimation in an optimum order. In another embodiment, a receiver performs multiple reactive tabu searches to estimate a transmitted vector. The receiver employs a fixed threshold or a variable threshold for a cost function used in the multiple reactive tabu searches depending on whether the MIMO system is under-determined or not. The techniques enable low bit-error rate (BER) performance in MIMO systems with large number of antennas and when higher-order modulation techniques are used.
    Type: Grant
    Filed: July 10, 2012
    Date of Patent: January 21, 2014
    Assignee: Indian Institute of Science
    Inventors: Ananthanarayanan Chockalingam, Balaji Sundar Rajan, Srinidhi Nagaraja, Tanumay Datta
  • Patent number: 8634504
    Abstract: A correlation calculating method of correlating a received code signal obtained by demodulating a received signal, which is a signal obtained by receiving a positioning satellite signal, with a replica code signal is provided which includes: correlating values of the replica code signal in a chip period with values of the received code signal at first to n-th arrival times obtained by varying an arrival time of the chip period by 1/n chip (where n is an integer equal to or greater than 2); and acquiring a correlation calculation result at a 1/n chip interval by synthesizing the correlation calculation results.
    Type: Grant
    Filed: March 22, 2011
    Date of Patent: January 21, 2014
    Assignee: Seiko Epson Corporation
    Inventors: Maho Terashima, Naoki Gobara
  • Patent number: 8630332
    Abstract: A signal processor for GPS or other GNSS radiolocalization systems, includes a RAM pre-correlation buffer which is filled in sync with the code NCO, thus all sample alignment in the buffer is fixed The device further includes an amplitude compressor to limit the size of the buffer memory and is optimized to provide data to the following DFT unit in small bursts that can be processed in real time without the need for intermediate buffers. Thanks to these features the processor limits the amount of fast intermediate memories, is simpler and has lowerpower consumption.
    Type: Grant
    Filed: May 9, 2008
    Date of Patent: January 14, 2014
    Assignee: QUALCOMM Incorporated
    Inventor: Philip John Young
  • Patent number: 8625656
    Abstract: Techniques for deriving channel estimates with different channel estimation filters are described. In one scheme, a filter selection metric is determined for a signal to be recovered, a channel estimation filter is selected based on the filter selection metric, and a channel estimate is derived with the selected channel estimation filter. In another scheme, a first channel estimate is derived with a first channel estimation filter having a first filter response, a first signal is recovered with the first channel estimate, and interference due to the first signal is estimated and removed. A second channel estimate is derived with a second channel estimation filter having a second filter response that is different from the first filter response.
    Type: Grant
    Filed: March 4, 2010
    Date of Patent: January 7, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Tao Luo, Aleksandar Damnjanovic, Durga Prasad Malladi
  • Patent number: 8615032
    Abstract: Sub-microsecond time transfer in a GPS/GNSS receiver using a weak GPS/GNSS signal is provided. The digitized complex baseband signal and the generated PN code are cross-correlated for each code period so as to output a complex correlation value at each code epoch of the generated PN code, where a sequence of the output correlation values form a data stream representing the navigation message. Bit synchronization generates bit sync pulses at bit boundaries. The location of a target segment having a known sequence at a known bit location in the navigation message is detected by searching through a plurality of subframes and accumulating search results for the plurality of subframes. Transmission time of the target segment is determined from the detected location of the target segment, with a certain time ambiguity. Accurate local time is determined by solving the time ambiguity using approximate time obtained from an external source.
    Type: Grant
    Filed: January 22, 2013
    Date of Patent: December 24, 2013
    Assignee: Magellan Systems Japan, Inc.
    Inventor: Lawrence R. Weill
  • Patent number: 8615058
    Abstract: A signal acquisition system efficiently acquires a transmitted signal even at very low power. The system may synchronize to a preamble structure in the transmitted signal and, for example, determine timing parameters that locate the preamble with respect to system timing or other clock references. The system is particularly effective at acquiring weak power signals and is also robust against significant noise and other impairments, and therefore improves the ability of a receiving device that incorporates the signal acquisition system to acquire the signal and establish communication with other devices.
    Type: Grant
    Filed: September 27, 2011
    Date of Patent: December 24, 2013
    Assignee: Broadcom Corporation
    Inventors: Ka Shun Carson Pun, Siavash Ekbatani, David Ho, Siukai Mak
  • Publication number: 20130336366
    Abstract: In an overlay, network-based, Wireless Location System, LMUs typically co-located with BTSs, are used to collect uplink radio signaling for use in TOA, TDOA and/or AoA positioning methods. In a UMTS, the dual nature of the uplink allows for identification of the correct uplink signal even in the presence of co-channel interference from other UMTS mobile devices.
    Type: Application
    Filed: June 19, 2012
    Publication date: December 19, 2013
    Applicant: TRUEPOSITION, INC.
    Inventor: Rashidus S. Mia
  • Patent number: 8611397
    Abstract: A direct-sequence spread spectrum (DSSS) receiver may be operable to process signal samples in frequency domain utilizing a prime factor fast Fourier transform (FFT) circuit and a pseudorandom noise (PRN) code. The DSSS receiver may be operable to transform the signal samples into FFT signal samples using the prime factor FFT circuit, transform the PRN code into a FFT PRN code using the prime factor FFT circuit and multiply the FFT signal samples with the FFT PRN code using the prime factor FFT circuit. The DSSS receiver may be operable to inversely transform the multiplied FFT signal samples into correlated signal samples using a prime factor inverse FFT (IFFT) implemented by the prime factor FFT circuit. The prime factor FFT circuit may comprise a prime length FFT core, a FFT memory, a register bank, a switch, a multiplier and a FFT controller.
    Type: Grant
    Filed: December 21, 2009
    Date of Patent: December 17, 2013
    Assignee: Broadcom Corporation
    Inventors: Charles Norman, Andreas Warloe, Charles Abraham, Jared Welz
  • Patent number: 8594153
    Abstract: A receiving system dynamically searches the communications band for transmissions of messages having the same nominal communications parameters, including the use of the same spreading code, but having potentially different specific frequencies and code-phases. The receiver, which is independent of the transmitters, samples the communications band at each code-phase of the spreading code over a span of downconverted transmission frequencies. When a message element is detected at a particular code-phase and frequency, it is forwarded to a demodulator that demodulates the message and sends it to its intended destination. In a preferred embodiment, a progressive Fourier Transform is used to incrementally determine the power level at each successive code-phase at a given frequency, thereby substantially reducing the time required to search for transmissions at each discrete code-phase.
    Type: Grant
    Filed: April 24, 2007
    Date of Patent: November 26, 2013
    Assignee: Comtech Mobile Datacom Corporation
    Inventor: Scott A. McDermott
  • Patent number: 8594151
    Abstract: A user equipment and corresponding method detect a frequency division permanent common pilot and include a controller configured to use a sliding correlator with a frequency division phase-shift, an averaging unit configured to average a peak magnitude output of the sliding correlator over a predetermined number of sub-frames for each of possible reference pilot sequence and each sample shift of the sliding correlator, and a maximum peak storing unit configured to store first and second maximum peaks depending on corresponding ratios and a threshold. The user equipment and method thereof also include a pilot sequence index candidate storing unit configured to store a pilot sequence index candidate for each shift of the sliding correlator. The user equipment and method thereof include a selector configured to select the pilot sequence index candidate with a lowest peak ratio to shift the sliding correlator.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: November 26, 2013
    Assignee: Nokia Corporation
    Inventors: Gilles Charbit, Ülo Parts, Kaj Jansen
  • Patent number: 8588272
    Abstract: Reference frames are selected for use in a frame reference buffer in a video encoding system, so as to provide long term prediction of motion in video sequences. Candidate reference frames are characterized by characteristic vectors. From the candidate reference frames, a number of reference frames are maintained in the frame buffer so as to obtain a specified distribution of the characteristic vectors over a vector space. Frames are selected for use in encoding a current frame based on the characteristic vector of the current frame and the reference frames in the frame buffer.
    Type: Grant
    Filed: July 24, 2012
    Date of Patent: November 19, 2013
    Assignee: VBrick Systems, Inc.
    Inventors: Sassan Pejhan, Andrew Krupiczka
  • Patent number: 8588270
    Abstract: The invention includes a method for transmitting and detecting high speed Ultra Wideband pulses across a wireless interface. The transmitter includes a serializer and pulse generator. The receiver comprises a fixed delay line, multiplier, local serializer (with a sequence matching the transmitter), digital delay lines, low noise amplifier and logic fan-out buffer along with an array of D flip-flop pairs. Each flip-flop pair is enabled, at fixed time increments, to detect signals at a precise time; the timing is controlled by the pseudo-random sequence generated by the local serializer. A local tunable oscillator is controlled by detecting the phase change of the incoming signal and applying compensation to maintain the phase alignment and clock synchronization of the receiver to the clock reference of the transmitter. The invention uses a pair of pulses with a fixed delay and then relies on mixing the two to provide better noise immunity.
    Type: Grant
    Filed: December 4, 2012
    Date of Patent: November 19, 2013
    Assignee: University of South Florida
    Inventor: James L. Tucker
  • Patent number: 8576964
    Abstract: There is provided a radio receiver including: a first matched filter, a second matched filter, a first frame synchronization determining unit and a first phase determining unit. The first matched filter performs matching processing on the basis of N first tap coefficients and sign information of a received digital signal to obtain first output data. The second matched filter performs matching processing on the basis of M (M is a natural number smaller than the N) second tap coefficients, the sign information and amplitude information of the received digital to obtain second output data. The first frame synchronization determining unit determines a first frame synchronization timing of the received digital signal on the basis of the first output data. The first phase determining unit determines a first phase amount of the received digital signal on the basis of the second output data and the first frame synchronization timing.
    Type: Grant
    Filed: March 1, 2012
    Date of Patent: November 5, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kentaro Taniguchi, Hirotsugu Kajihara