Multi-receiver Or Interference Cancellation Patents (Class 375/148)
  • Patent number: 8995559
    Abstract: Techniques for sending signaling messages in a wireless communication network are described. In an aspect, a signaling message (e.g., a reduce interference request) may be sent by mapping it to at least one specific subcarrier among a set of subcarriers reserved for sending the signaling message. The at least one subcarrier may be selected based on the message value. A signal may be sent on the at least one subcarrier in multiple symbol periods to convey the signaling message. In another aspect, a reduce interference request may be sent based on an orthogonal resource among orthogonal resources available for sending reduce interference requests. In one design, an orthogonal sequence may be selected based on the request and may be spread across a resource segment. In another design, the reduce interference request may be processed to obtain modulation symbols, and each modulation symbol may be spread across multiple subcarriers in one symbol period.
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: March 31, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Ravi Palanki, Alexei Y. Gorokhov
  • Patent number: 8995499
    Abstract: In one aspect, the teachings herein disclose a method and apparatus for signal quality reporting from a wireless apparatus that better reflects the actual interference cancellation efficiency expected at the wireless apparatus for a given transmission interval. In one example, the wireless apparatus knows or predicts the particular modulation and coding schemes (MCSs) that will be used in the transmission of one or more interferer signals for a transmission interval of interest. In turn, it uses those MCS values to estimate the actual interference cancellation efficiency the wireless apparatus will achieve with respect to those interferers. The wireless apparatus estimates and reports signal quality according to its estimated interference cancellation efficiency.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: March 31, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Andres Reial, Andreas Cedergren
  • Publication number: 20150085900
    Abstract: This acquisition method is provided for acquiring a satellite signal emitted by a radio navigation satellite, the satellite signal containing a cyclic pseudo-random identification code specific to the satellite. The acquisition method includes the generation of a local code producing a replica of the identification code, and the production of a combined correlation (EDDC) of a received signal with the local code, the combined correlation corresponding to the linear combination of a first double delta correlation and of a second narrow correlation.
    Type: Application
    Filed: September 23, 2014
    Publication date: March 26, 2015
    Inventors: Bernard FOUILLAND, Patrick VIEUX
  • Patent number: 8989287
    Abstract: A circuit for use in a complementary Golay sequence generator or in a complementary Golay sequence correlator includes an input configured to receive an input signal, a set of delay elements, including delay elements corresponding to respective delays of 1, 2, 4, 8, 16, 32, and 64, and a set of multipliers interconnected with the input and the set of delay elements. The set of multipliers is configured to apply weight factors, and the weight factors define the sequence 1,1,?1,1,?1,1,?1. The circuit also includes a pair of outputs configured to output, in response to the input signal, one of (i) a pair of complementary Golay sequences or (ii) a pair of correlation output signals, using (a) the set of delay elements and (b) the set of weight multipliers.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: March 24, 2015
    Assignee: Marvell World Trade Ltd.
    Inventors: Hongyuan Zhang, Rohit U. Nabar, Songping Wu, Hui-Ling Lou
  • Patent number: 8989326
    Abstract: A receiver architecture for processing spread spectrum signals. The receiver has an RF front end to receive and down convert a broadcast signal to an intermediate frequency carrier. The IF signal is digitized and provided to a processor (which may be a software-driven DSP, an ASIC or other embodiment) for processing. A given IF carrier is removed and the signal is low pass filtered. The signal is provided to a number of channels, each, for example, correspond to a unique transmitter. On each channel the sample rate is reduced to a predetermined fixed rate with timing mismatch compensated. The Doppler frequency shift, as estimated for the channel, is removed succeedingly. A locally generated copy of the spreading code used by the transmitter is applied to the carrier and Doppler removed signal at the predetermined fixed sample rate. The de-spread signal is used to provide estimates of the Doppler shift and for subsequent sample selection.
    Type: Grant
    Filed: October 24, 2013
    Date of Patent: March 24, 2015
    Assignee: Analog Devices, Inc.
    Inventors: Wei An, Josef Stein
  • Patent number: 8989817
    Abstract: Method and apparatus related to implementing and/or utilizing different polarization antennas with different corresponding average transmit power levels are described. Inter-cell interference is mitigated by having different cells with different power relationships between polarizations antennas. For example, a first base station transmits at a high average power level on its vertical polarization antenna and transmits at a low average power level on its horizontal polarization antenna. Concurrently, a second base station, which is adjacent to the first base station, transmits at a low average power level on its vertical polarization antenna and transmits at a high average power level on its horizontal polarization antenna. In some hexagonal deployment schemes a base station has at most two adjacent base stations using the same power level to antenna polarization direction relationship as it is using.
    Type: Grant
    Filed: March 6, 2008
    Date of Patent: March 24, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Xinzhou Wu, Vikram Reddy Anreddy, Junyi Li, Rajiv Laroia
  • Patent number: 8989235
    Abstract: A system that incorporates the subject disclosure may perform, for example, a method for receiving interference information from each of the plurality of communication devices detecting interference information in a plurality of segments of a radio frequency spectrum, correlating the interference information of the plurality of communication devices to generate correlated information, and identifying a plurality of interferers according to the correlated information. Other embodiments are disclosed.
    Type: Grant
    Filed: August 2, 2013
    Date of Patent: March 24, 2015
    Assignee: ISCO International, LLC
    Inventors: Amr Abdelmonem, Sean S. Cordone, Dariusz Seskiewicz, Bill Myers, Krishna Komoravolu
  • Patent number: 8989244
    Abstract: A receiver is provided that receives signals from a device under test (DUT) for one or more modes of operation. For each mode, the system detects beacon transmission signals from the DUT, and counts the number of beacons for a period of time. If the count is not consistent with an expected count, e.g. a stored value, the system may preferably provide an output to indicate that there is a problem with the DUT. If the count is consistent with the expected count, the system may preferably perform further testing for other modes of operation. If the count output of the DUT is consistent with expected counts over each of the operation modes, the system may provide an indication that the DUT has passed the beacon tests.
    Type: Grant
    Filed: December 10, 2012
    Date of Patent: March 24, 2015
    Assignee: NETGEAR, Inc.
    Inventors: Joseph Amalan Arul Emmanuel, Jonathan M. Hummel, Shahrokh M. Zardoshti
  • Publication number: 20150078420
    Abstract: An amplification circuit (100) comprising a first filter (102) and an LNA (110). The first filter (102) comprising an input (104) for receiving an input signal; a first differential output (106); and a second differential output (108). The first filter (102) has a differential mode of operation for frequencies in its pass-band (706, 806) and a common mode of operation for frequencies outside its pass-band (706, 806), and may be an acoustic wave filter. The LNA (110) comprising a first differential input (112) connected to the first differential output (106) of the first filter (102); a second differential input (114) connected to the second differential output (108) of the first filter (102); and an output (116) for providing an amplified output signal.
    Type: Application
    Filed: July 29, 2014
    Publication date: March 19, 2015
    Inventors: Marcel Geurts, Louis Praamsma, Michel Groenewegen, Rainier Breunisse, Freek van Straten, Robert Buytenhuijs
  • Patent number: 8982928
    Abstract: A method for detecting multi-user signals including conducting a first energy burst detection detecting a first plurality of user signals as a first energy burst, attempting to decode a user signal from the first plurality of signals within the first energy burst, cancelling out a first user signal from the first energy burst if the first user signal is successfully decoded from the first energy burst, determining a second user signal to be discarded if the second user signal is not successfully decoded from the first energy burst, conducting a second energy burst detection detecting a second plurality of signals as a second burst, and iteratively cancelling out the first user signal successfully decoded from the first energy burst from the second energy burst, wherein the second energy burst detection is conducted when all user signals within the first energy burst are either cancelled out or determined to be discarded.
    Type: Grant
    Filed: September 30, 2013
    Date of Patent: March 17, 2015
    Assignee: Comtech Mobile Datacom Corporation
    Inventors: Richard Candell, Paul Ebert, John Fossaceca, Greg Handermann, Mark Holland, Lajuana Johnson, Bruce L. McKinley, Bo Wang, Ralph Eugene Crenshaw
  • Patent number: 8976840
    Abstract: The method disclosed herein is implemented in a radio receiver to detect an AWGN channel, where the radio receiver comprises a rake receiver. The radio receiver receives signals transmitted via a propagation channel from a transmitter, and determines that the propagation channel is an AWGN channel when a filtered version of a minimum value of a metric is lower than a threshold value. The metric relates to a difference between a normalized measured power profile of the propagation channel and a normalized power template, which normalized power template is dependent on predetermined sampling timing shifts and on rake finger positions within the rake receiver.
    Type: Grant
    Filed: May 30, 2014
    Date of Patent: March 10, 2015
    Assignee: ST-Ericsson SA
    Inventors: Kazuyoshi Uesaka, Elias Jonsson, Hisashi Onozawa
  • Patent number: 8976917
    Abstract: A receiver communicating according to a wireless communication protocol standard for filtering a signal received at a single antenna. The receiver includes filter modules, receiver modules, and a summer. The filter modules receive from antennas multipath components of the signal as transmitted to the receiver. The signal includes bits of data. Each of the filter modules: receives corresponding ones of the multipath components of the signal as received at a respective one of the antennas; and according to the wireless communication protocol standard, filters the signal as received at the respective one of the antennas to generate a filtered signal. The receiver modules respectively receive the filtered signals. Each of the receiver modules combines the multipath components in the respective filtered signal to generate an output signal. Each of the output signals includes a respective version of the bits of data. The summer sums the output signals.
    Type: Grant
    Filed: March 18, 2014
    Date of Patent: March 10, 2015
    Assignee: Marvell World Trade Ltd.
    Inventors: Zhiyu Yang, Hongyuan Zhang
  • Patent number: 8976918
    Abstract: A wireless communication device includes a reception processing circuit including a weight coefficient computation circuit that includes a computation circuit to compute a weight coefficient which is used for removing a distortion of a reception signal caused by a multi-path, and which of each of fingers corresponds to each of a specified number of paths among a plurality of paths caused by the multi-path between the device and the opposing device, by iteratively performing a computation including a complex multiplication between a weight coefficient while being iteratively computed and a component of a correlation matrix, and a control circuit to cause the computation circuit to compute complex multiplications between a first (second) component of a pair of components having a complex conjugate relationship and a first (second) weight coefficient while being iteratively computed when the pair of components is present among components used for computing the weight coefficient.
    Type: Grant
    Filed: May 23, 2014
    Date of Patent: March 10, 2015
    Assignee: Fujitsu Limited
    Inventor: Jun Kameya
  • Patent number: 8976885
    Abstract: A method of calculating combining weight vectors associated with a received composite information signal comprising at least one data stream transmitted from at least a first antenna and a second antenna is disclosed. The method starts with computing a parametric estimate of an impairment covariance matrix including at least a first impairment term associated with common pilots deployed by the first antenna and the second antenna respectively. The first impairment term captures effects of interferences between the common pilots, in addition to effects of interferences caused by each common pilot singly. The impairment covariance matrix further includes a data covariance term capturing effects of the at least one data stream and an interference term caused at least partially by contribution of thermal noise of receiver branches. Then the method computes the combining weight vector using the computed impairment covariance matrix.
    Type: Grant
    Filed: January 22, 2013
    Date of Patent: March 10, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Michael Samuel Bebawy, Stephen Grant
  • Patent number: 8971386
    Abstract: The invention relates to the field of radio signal receivers for use in wireless communication networks. In particular to a receiver unit having at least one antenna input for receiving multipath radio signals via a radio unit and at least one antenna from one or more user equipments is provided. The receiver unit comprises: a despreading unit configured to despread a multipath radio signal in the received multipath radio signals using a number of despreading fingers corresponding to a number of delay positions in the multipath radio signal which corresponds to a number of paths in the multipath radio signal, and a combining unit configured to apply at least one weight to the output of each of the number of allocated despreading fingers and combine the weighted outputs into a resulting equalized radio signal.
    Type: Grant
    Filed: August 17, 2011
    Date of Patent: March 3, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Henrik Egnell, Nina Blom
  • Patent number: 8971383
    Abstract: Systems and methods for generating a CDMA signal s(t) comprising N components involves assigning to each of the N components one unique spreading sequence an selected from a set of M spreading sequences with M?N, modulating the symbols dn of each component on the assigned unique spreading sequence an, and combining the N symbols dn each being spread with its own unique spreading sequence an to a CDMA signal s(t). The assigned spreading sequences an are selected such that all selected pairs within the set of N spreading sequences are orthogonal or very close to be orthogonal so that cross-correlation components between all spreading sequences an are close to zero or zero.
    Type: Grant
    Filed: August 23, 2013
    Date of Patent: March 3, 2015
    Assignees: STMicroelectronics (Research & Development) Ltd., Astrium GmbH
    Inventors: Francis Soualle, Jean-Jacques Floch, Philip Mattos
  • Patent number: 8971460
    Abstract: A wireless receiving apparatus includes a spurious component extraction unit, and a spurious cancellation unit. The spurious component extraction unit is configured to cancel a desired wave with a multi-antenna configuration, and extract spurious components. The spurious cancellation unit is configured to cancel spurious in received signals by using the spurious components extracted. A first correlation unit in the spurious component extraction unit finds a correlation between an output of the spurious extraction unit and an output of the spurious cancellation unit.
    Type: Grant
    Filed: December 19, 2013
    Date of Patent: March 3, 2015
    Assignee: Fujitsu Limited
    Inventors: Hideki Furudate, Takanori Iwamatsu
  • Patent number: 8971385
    Abstract: A method and arrangement are disclosed for acquiring a spread spectrum signal produced by means of transmitter-end spreading of a bit sequence using a spread code signal, which provide for the reception of the spread spectrum signal; provision of a receiver-end spread code signal which corresponds to the transmitter-end spread code signal; performance of polyphase correlations for respective different code phases which give rise to polyphase correlation results which are each associated with different code phases; filtration using at least two of the code phases; determination of an extreme value in the filtered polyphase correlation results, and determination of the code phase which is associated with the extreme value.
    Type: Grant
    Filed: November 22, 2011
    Date of Patent: March 3, 2015
    Assignee: Continental Automotive GmbH
    Inventor: Martin Opitz
  • Patent number: 8964912
    Abstract: A method and apparatus for determining operating modes in a receiver is described herein. A delay searcher in the receiver detects a signal image in the received signal. When the receiver is a RAKE receiver, a plurality of RAKE fingers coherently combine time-shifted versions of the received signal at different delays. Alternatively, when the receiver is a chip equalization receiver, an FIR filter coherently pre-combines the signal images in the received signal. A processor determines delays. In particular, the processor generates a first signal quality metric for a single-delay receiver mode, and generates a second signal quality metric for a multi-delay receiver mode. Based on a comparison of the first and second signal quality metrics, the processor selects the single-delay or the multi-delay receiver mode for processing the signal image.
    Type: Grant
    Filed: September 2, 2005
    Date of Patent: February 24, 2015
    Assignee: Telefonaktiebolaget LM Ericsson (PUBL)
    Inventors: Douglas A. Cairns, Gregory E. Bottomley, Yi-Pin Eric Wang
  • Patent number: 8964812
    Abstract: A method including: using both dedicated circuitry and a programmable processor system for acquisition of a communication channel; and using the dedicated circuitry for tracking the acquired communication channel while using the programmable processor system for hosting an application that uses information dependent upon data dependent on the acquired communication channel.
    Type: Grant
    Filed: May 24, 2006
    Date of Patent: February 24, 2015
    Assignee: Nokia Corporation
    Inventor: Philip Geoffrey Eade
  • Patent number: 8953563
    Abstract: A base station includes a reference signal sequence generator configured to generate a reference signal sequence for each of n antenna ports using one initialization seed, n being a positive integer. The base station also includes n spreaders. Each spreader corresponds to a respective one of the n antenna ports and is configured to receive a respective reference signal sequence for the respective antenna port from the reference signal sequence generator and spread the respective reference signal sequence using a respective Walsh code. The base station further includes n resource element mappers. Each mapper corresponds to a respective one of the n antenna ports and is configured to receive a respective spread reference signal sequence from a respective spreader and map the respective spread reference signal sequence to a set of reference signal resource elements corresponding to a respective antenna port.
    Type: Grant
    Filed: March 29, 2010
    Date of Patent: February 10, 2015
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Young-Han Nam, Jianzhong Zhang
  • Patent number: 8948702
    Abstract: An antenna system and method utilize an evaluation branch circuit and an implementation branch circuit. These circuits are each connected to both a first antenna input and a second antenna input. An output of the evaluation branch circuit is in communication with a controller while an output of the implementation branch circuit is in communication with a receiver. Each branch circuit includes at least one signal conditioner to change an electrical characteristic of RF signals received from antennas via the antenna inputs. The evaluation branch circuit, controlled by the controller, changes the electrical characteristics of the RF signals in a variety of different ways to discover an optimized evaluation RF signal. Once the optimized evaluation RF signal is determined, the implementation branch circuit is controlled, by the controller, to produce an optimized implementation RF signal in accordance with that discovered by the evaluation branch circuit.
    Type: Grant
    Filed: June 15, 2010
    Date of Patent: February 3, 2015
    Assignee: AGC Automotive Americas R&D, Inc.
    Inventors: Ming Lee, Wladimiro Villarroel, Kwan-ho Lee, Yasutaka Horiki
  • Patent number: 8942634
    Abstract: Aspects of a method and system for interference suppression using information from non-listened base stations are provided. A wireless communication device may be operable to receive a raw signal comprising one or more desired signals from one or more serving base transceiver stations (BTSs) and comprising one or more undesired signals from one or more non-listened BTSs. The wireless communication device may be operable to generate first estimate signals that estimate the one or more undesired signals as transmitted by the one or more non-listened BTSs, generate an interference suppressed version of the raw signal based on the first estimate signals, and recover the one or more desired signals from the interference suppressed version of the raw signal. The non-listened BTSs may comprise one or more BTSs that are not serving the wireless communication device and are not involved in a hand off of the wireless communication device.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: January 27, 2015
    Assignee: Broadcom Corporation
    Inventors: Mark Hahm, Wei Luo
  • Patent number: 8937884
    Abstract: Interference cognitive devices are described. An interference cognitive device can be collocated with a transmitter of an interference cognitive transmitter (ICT), as receive chains or portions thereof at the ICT. An interference cognitive device can also be remote with respect to the transmitter, which operates in an interference cognitive network and receives data directly or indirectly from the interference cognitive device. The ICT uses the data to mitigate interference while continuing to operate in accordance with a performance metric.
    Type: Grant
    Filed: December 15, 2012
    Date of Patent: January 20, 2015
    Assignee: Quantenna Communications Inc.
    Inventors: Andrea Goldsmith, Ravi Narasimhan
  • Patent number: 8934519
    Abstract: Methods and apparatus are disclosed for receiving a diversity transmitted signal using a Rake or G-Rake receiver in a radio system. Signals are diversity transmitted in a first and second symbol period by two or more antennas. One or more receive antennas receive the diverse transmit signals. Weights are generated to account for the correlation between the channels over which the diverse transmit signals are transmitted in the first and second symbol period and are used to weight the received signals. The weighted signals are then fed to a mutual receiver.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: January 13, 2015
    Assignee: Telefonaktiebolaget LM Ericsson (Publ)
    Inventors: Qingyu Miao, Hai Wang
  • Patent number: 8934521
    Abstract: A receiver circuit provides improved noise estimation processing by at least partially removing receiver frequency error bias. An initial noise estimate is compensated using an error term based on the observed receiver frequency error, and the resulting compensated noise estimate can be used to improve other signal processing in the receiver. For example, the receiver may use compensated noise estimates to generate signal quality estimates, e.g., Signal-to-Interference (SIR) estimates, having improved accuracy. Additionally, or alternatively, the receiver may use the compensated noise estimates to generate RAKE combining weights having improved noise suppression characteristics. In an exemplary embodiment, the initial noise estimate is a noise correlation matrix generated from a received reference signal, e.g., pilot symbols, and the error term is an error matrix directly generated using the observed receiver frequency error and channel estimates taken from the reference signal.
    Type: Grant
    Filed: June 26, 2013
    Date of Patent: January 13, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventor: Anders Wallén
  • Patent number: 8934520
    Abstract: A method, receiver and program for processing radio signals to identity an n-ray channel condition. The method comprises: receiving signal samples and estimating a plurality of channel taps from the samples; estimating for each of the channel taps a signal power and a disturbance power; filtering the signal power to provide a filtered signal power quantity; filtering the disturbance power to provide a filtered disturbance power quantity; using the filtered power quantities to determine n strongest channel taps; generating first and second comparison parameters using the strongest channel taps and at least one other channel tap; providing a comparison result based on the first and second comparison parameters and a threshold value, and; identifying an n-ray channel condition from the comparison result.
    Type: Grant
    Filed: January 27, 2011
    Date of Patent: January 13, 2015
    Assignee: Icera Inc.
    Inventors: Carlo Luschi, Abdelkader Medles, Gang Wang
  • Patent number: 8934384
    Abstract: A navigation system includes a correlation engine configured to despread a received signal. The correlation engine includes a correlator configured to evaluate the received signal against a replica signal to produce a correlation result, and a packet encoder configured to produce a packet comprising a destination address, a source address, and the correlation result. An input/output interface is configured to provide the packet to another component in the navigation system.
    Type: Grant
    Filed: August 23, 2012
    Date of Patent: January 13, 2015
    Assignee: Northrop Grumman Systems Corporation
    Inventors: Sanjeev Gunawardena, Jeff Dickman, Mathew A. Cosgrove
  • Publication number: 20150010043
    Abstract: An interference cancelling receiver combines data from multiple paths after aligning to transmitter timing, and uses either an equalizer or a Rake receiver to compute symbol estimates. Interference estimates are generated from the symbol estimates, and multiple interference estimates are combined after re-aligning the interference estimates to receiver timing. At least two segments of symbol estimates are computed for each segment of interference cancelled data. Various techniques may be employed for controlling the latency and sequencing of these operations, and the subsystems within the canceller may use different processing clock speeds.
    Type: Application
    Filed: September 19, 2014
    Publication date: January 8, 2015
    Applicant: III Holdings 1, LLC
    Inventors: Anand P. Narayan, Greg Graham, David R. Meyer, Prashant Jain
  • Patent number: 8929494
    Abstract: Systems and methods for reading RFID tags using joint beamforming and preamble detection in accordance with embodiments of the invention are disclosed. One embodiment includes an antenna array comprising a plurality of antenna elements, a joint beamformer and preamble detector configured to receive inputs from each of the antenna elements, and a decoder configured to receive a resampled signal from the joint beamformer and preamble detector and to decode data using the resampled signal. In addition, the joint beamformer and preamble detector is configured to correlate the inputs from the antenna elements against a correlation sequence at a plurality of starting sample positions and predetermined rates, use the correlations to select a starting sample position and rate for decoding the received signal, use the correlations to determine beamforming coefficients for combining the inputs, and resample the combined inputs based upon the selected starting sample position and rate.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: January 6, 2015
    Assignee: Mojix, Inc.
    Inventors: Dong-U Lee, Christopher R. Jones
  • Patent number: 8929491
    Abstract: A method and apparatus are provided for cancelling interferences of a received MIMO RF signal. The method includes: receiving a signal y; an initial step of obtaining, from the received signal y, at least one data representative of the received signal, called decoded data; computing the decoded data as a function of at least one predetermined criterion, delivering feedback data and a feedback decision; and, as a function of the feedback decision, at least one iteration of the following steps: constructing a set of feedback symbols from the feedback data; obtaining, from the set of feedback symbols, at least one data representative of a feedback decoded signal, called feedback decoded data; computing the at least one feedback decoded data as a function of the at least one predetermined criterion, delivering the feedback data.
    Type: Grant
    Filed: November 26, 2012
    Date of Patent: January 6, 2015
    Assignee: Sequans Communications
    Inventors: Yang Liu, Serdar Sezginer
  • Patent number: 8929421
    Abstract: A successive interference cancellation method includes: determining whether a current interfering user channel is a service cell channel of a service cell or a neighbor cell channel of a neighbor cell; correcting a phase rotation of a user signal of the neighbor channel when the interfering user channel is the neighbor cell channel; determining a tentative ruling for a user signal of the neighbor cell channel; restoring the phase rotation of the user signal of the neighbor cell channel; performing a signal reconstruction on the neighbor cell channel to obtain a reconstructed signal of the neighbor cell channel; removing the reconstructed signal of the neighbor cell channel from a reception signal to obtain a corrected signal, and completing successive interference cancellation on the current interfering user channel. With the above successive interference cancellation method, accuracy of successive interference cancellation as well as system detection performance is enhanced.
    Type: Grant
    Filed: July 25, 2013
    Date of Patent: January 6, 2015
    Assignee: MStar Semiconductor, Inc.
    Inventor: Long-Bao Jin
  • Publication number: 20150003500
    Abstract: Briefly, in accordance with one or more embodiments, a platform may comprise a receiver to receive a signal that includes an error in the received signal due to a noise signal generated in the platform, and a processor configured to calculate a noise vector from a source of the noise signal. The noise vector may be de-spread. The receiver may include digital signal processing configured to estimate an error vector based at least in part on the noise vector and to subtract the estimated error vector from the received signal to cancel the noise signal from the received signal. The noise cancelled from the received signal may include platform noise generated by a bus, a memory circuit, a clock, a power supply, a circuit ground or integrated circuit substrate, or input/output circuit of the platform.
    Type: Application
    Filed: June 27, 2013
    Publication date: January 1, 2015
    Inventor: Dawson W. Kesling
  • Patent number: 8924220
    Abstract: In a multiband compressor 100, a level calculation unit 121 calculates a signal level inputted for each of bands, a gain calculation unit 122 calculates a gain value from the calculated signal level, and a gain limitation unit 130 limits a gain value by comparison with a gain value of the other band in a compressor for each band. With this configuration, provided is a multiband compressor capable of achieving a balance between the quality of sound and the effect of enhancing the sound level at a high level.
    Type: Grant
    Filed: September 7, 2010
    Date of Patent: December 30, 2014
    Assignee: Lenovo Innovations Limited (Hong Kong)
    Inventor: Satoshi Hosokawa
  • Publication number: 20140376598
    Abstract: A method for mitigating a multi-path-induced error in a global navigation satellite system comprises, for a respective measurement epoch, obtaining respective representations of a composite signal including a plurality of value-pairs of the composite signal. The method further comprises, with respect to the measurement epoch: obtaining a plurality of coefficients for a set of linear equations based on the plurality of value-pairs of the composite signal; iteratively obtaining solutions for the set of linear equations, thereby solving for a code tracking timing offset, a time delay of a multi-path signal of the composite signal relative to its direct-path signal, and orthogonal representations of the multi-path signal; determining a phase error between the composite signal and the direct-path signal, due to the time delay, in accordance with the orthogonal representations of the multi-path signal; and correcting for the code tracking timing offset and the phase error.
    Type: Application
    Filed: March 6, 2014
    Publication date: December 25, 2014
    Applicant: Deere & Company
    Inventors: Richard G. Keegan, Ronald R. Hatch
  • Patent number: 8913100
    Abstract: A mobile device, and a method and computer program product for displaying a streaming video image at the mobile device during a packet based video call via a channel established over a wireless communication network, the method includes receiving a speed indication of the mobile device and sending said indication to a communication client application; and responsive to receiving said indication, the communication client application is configured to limit the amount of information in the streaming video image that is supplied for display on a display of the mobile device during the video call when the speed of the mobile device is greater than, or equal to, a first predetermined speed threshold.
    Type: Grant
    Filed: December 30, 2011
    Date of Patent: December 16, 2014
    Assignee: Skype
    Inventor: Sten Tamkivi
  • Publication number: 20140362892
    Abstract: Systems, methods, apparatuses, and computer readable media are disclosed for providing interference rejection in ultra-wideband real time locating systems. In one embodiment, an ultra-wideband (UWB) receiver is configured to: receive an interference signal from a source positioned outside a monitored region; receive a composite signal transmitted from a tagged object moving about a playing field within the monitored region, wherein the composite signal comprises a location signal and a component of the interference signal; detect whether the component of the interference signal exceeds a threshold value; and adjust, via a processor, filtering of the composite signal to attenuate the component of the interference signal based on whether the component of the interference signal exceeds the threshold value. Some embodiments provide for filtering of the composite signal using a combiner while others employ a tunable notch filter.
    Type: Application
    Filed: July 15, 2013
    Publication date: December 11, 2014
    Inventor: Edward A. Richley
  • Patent number: 8908743
    Abstract: A multi user receiver configured to receive a signal including multiple symbol streams assigned to various users is described. The multiple symbol streams include at least one first symbol stream assigned to a user of the multi user receiver and at least one second symbol stream assigned to another user, wherein a modulation alphabet applied for the at least one second symbol stream is unknown at the multi user receiver. The multi user receiver includes a symbol stream election unit configured to elect a symbol stream of the multiple symbol streams, an equalizer configured to provide an equalized symbol of the elected symbol stream, and a detector configured to generate a detected symbol from the equalized symbol on the basis of a constellation, wherein, if the second symbol stream is elected, the constellation is a mixed constellation including constellation points of at least two of multiple predefined modulation alphabets.
    Type: Grant
    Filed: September 26, 2012
    Date of Patent: December 9, 2014
    Assignee: Intel Mobile Communications GmbH
    Inventors: Biljana Badic, Tobias Scholand, Rajarajan Balraj, Peter Jung, Guido Bruck, Zijian Bai, Stanislaus Iwelski
  • Patent number: 8908817
    Abstract: Example embodiments comprise a diversity receiver, and corresponding method, for measuring a differential phase between a first local oscillator of a first antenna and a second local oscillator of a second antenna in the presence of a primary interference signal and at least one secondary interference signal. The method may comprise receiving a primary communication signal, a primary reference signal and additional reference signals, and processing these signals such that a summation signal does not substantially comprise the at least one secondary interference signal. The estimation of differential phase is achieved by a phase shift calculation between processed signal components, using that a summation of all signal components equals, or is approximately equal to, a predetermined signal.
    Type: Grant
    Filed: September 28, 2011
    Date of Patent: December 9, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Mats Rydström, Dan Weinholt
  • Patent number: 8908781
    Abstract: A receiver and method for receiving and processing a sequence of transmitted symbols in a digital communication system utilizing soft pilot symbols. A set of soft pilot symbols are transmitted with higher reliability than the remaining symbols in the sequence by modulating the soft pilot symbols with a lower order modulation such as BPSK or QPSK while modulating the remaining symbols with a higher order modulation such as 16 QAM or 64 QAM. The receiver knows the modulation type and location (time/frequency/code) of the soft pilot symbols, and demodulates them first. The receiver uses the demodulated soft pilot symbols as known symbols to estimate parameters of the received radio signal. Unlike traditional fixed pilots, the soft pilots still carry some data. Additionally, the soft pilots are particularly helpful in establishing the amplitude reference essential in demodulating the higher order modulation symbols.
    Type: Grant
    Filed: February 23, 2012
    Date of Patent: December 9, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Douglas Cairns, Elias Jonsson
  • Publication number: 20140355654
    Abstract: The method disclosed herein is implemented in a radio receiver to detect an AWGN channel, where the radio receiver comprises a rake receiver. The radio receiver receives signals transmitted via a propagation channel from a transmitter, and determines that the propagation channel is an AWGN channel when a filtered version of a minimum value of a metric is lower than a threshold value. The metric relates to a difference between a normalized measured power profile of the propagation channel and a normalized power template, which normalized power template is dependent on predetermined sampling timing shifts and on rake finger positions within the rake receiver.
    Type: Application
    Filed: May 30, 2014
    Publication date: December 4, 2014
    Applicant: ST-Ericsson SA
    Inventors: Kazuyoshi Uesaka, Elias Jonsson, Hisashi Onozawa
  • Patent number: 8902365
    Abstract: Various embodiments are described herein for a universal television receiver that is capable of processing television channel signals broadcast according to a variety of analog and digital broadcast standards. In particular, various embodiments are provided for avoiding interferers in a desired television channel signal and these embodiments generally include changing sampling rate, shifting certain oscillation frequencies or changing sampling rate and shifting certain oscillation frequencies.
    Type: Grant
    Filed: February 27, 2008
    Date of Patent: December 2, 2014
    Inventors: Lance Greggain, Vyacheslav Shyshkin, Chris Ouslis, Steve Selby
  • Publication number: 20140348215
    Abstract: For determining paths in the scope of a multipath search, a device for use in a wireless communications system performs: obtaining a delay profile of a code division multiple access transmission signal, the delay profile being in a form of complex symbols, each complex symbols resulting from a despreading of said received signal after being delayed by a distinct delay; comparing the real part of said complex symbols forming the delay profile with a first threshold, the first threshold being determined on the basis of a noise level determined by the imaginary part of said complex symbols forming the delay profile; and determining said paths on the basis of the comparing.
    Type: Application
    Filed: December 27, 2011
    Publication date: November 27, 2014
    Applicant: Broadcom Corportion
    Inventors: Arnaud Rigolle, Pierre Didier
  • Patent number: 8897735
    Abstract: Disclosed is a self-correlation receiver of a transceiver in which a transmitter shares an antenna with a receiver. The self-correlation receiver includes: a clamper which receives a received signal, limits the magnitude of the received signal within a predetermined range and outputs a clamping signal; and a mixer which receives the received signal and the clamping signal and outputs a signal having a difference frequency between the received signal and the clamping signal.
    Type: Grant
    Filed: August 29, 2011
    Date of Patent: November 25, 2014
    Assignee: Intellectual Discovery Co., Ltd.
    Inventors: Eun-Hee Kim, Jin-Ho Ko
  • Patent number: 8897338
    Abstract: A receiver receives multipath signals in a W-CDMA system. Channel estimates and timing reference signals are generated utilizing the received multipath signals. Timing correction signals indicating a location of the received multipath signals may be generated and the received multipath signals may be combined based on the computed channel estimates and/or the generated timing reference signals. The multipath signals may be combined as a signal cluster. Circuitry may be provided that computes channel estimates based on at least one of a plurality of received multipath signals, and generates timing reference signals indicating a location of at least one of the plurality of received multipath signals. Circuitry may also be provided that combines at least a portion of the plurality of received multipath signals based on at least a portion of the computed channel estimates and/or the generated timing reference signals.
    Type: Grant
    Filed: August 23, 2012
    Date of Patent: November 25, 2014
    Assignee: Broadcom Corporation
    Inventors: Mark Kent, Vinko Erceg, Uri M. Landau, Pieter Van Rooyen
  • Patent number: 8897353
    Abstract: An OFDM receiver receives OFDM symbols in the frequency domain and comb filters and then punctures the OFDM symbols to leave symbols with actual pilot information and with null values at the data symbols. The receiver provides the punctured OFDM symbols to an OFDM symbol queue. A virtual pilot interpolator is coupled to the punctured OFDM symbol storage to generate virtual pilot information introduced to OFDM symbols. The interpolator may be a two dimensional Wiener filter. The receiver also includes a time domain channel estimator that processes a first OFDM symbol including virtual pilot information to generate a channel impulse response for the first OFDM symbol. A frequency equalizer equalizes the OFDM symbol in response to the channel impulse response for the first OFDM symbol.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: November 25, 2014
    Assignee: Acorn Technologies, Inc.
    Inventors: Steven C Thompson, Fernando Lopez de Victoria
  • Patent number: 8897407
    Abstract: An RF (e.g., GNSS) interference mitigation system and method uses a switchable bank of filters for selectively blocking signals in predetermined bandwidths based on detecting strong, interfering signals with an interference detection circuit including a sniffer antenna. A low-strength RF (e.g., GNSS) system can be combined with a spectrally-close high-strength, telecommunications receiver system for cooperative control. Alternatively, an RF receiver can detect tones, changes in DC bias or level changes to activate a filter selection switch.
    Type: Grant
    Filed: December 4, 2012
    Date of Patent: November 25, 2014
    Assignee: Hemisphere GNSS Inc.
    Inventors: Bradley P. Badke, Michael L. Whitehead, Walter J. Feller, Gregory J. Durnan
  • Patent number: 8897385
    Abstract: A method of estimating the Doppler spread of a communication channel includes computing a first sum defined by a difference between the pilot tones of a first group of N symbols and a corresponding pilot tones of a second group of N symbols preceding the first group of N symbols, computing a second sum defined by the pilot tones of the second group of N symbols, and computing a ratio of the first sum and the second sum for each of the N symbols of the first and second group of symbols to generate N ratios representative of the Doppler spread of the channel. The first sum is further defined by the square of the difference between the pilot tones of the first group of N symbols and the corresponding pilot tones of the second group of N symbols.
    Type: Grant
    Filed: October 12, 2010
    Date of Patent: November 25, 2014
    Assignee: MaxLinear, Inc.
    Inventor: Sridhar Ramesh
  • Patent number: 8897339
    Abstract: A method and arrangement of increasing impairment co-variance matrix Ru estimation accuracy in downlink in a user equipment in a communication network system. De-spread is performed on HS-DSCH symbols to form a matrix X of de-spread symbols. The matrix X and channel estimates hc from CPiCH and modulation scheme information are used to form a matrix S of recovered symbols in hard value. The matrix X and the channel estimates hc, the modulation scheme information and the matrix S output are used to increase the estimation accuracy of the matrix S. The previous step is repeated until the output symbols are the same as the input symbols or the number of iterations reaches a pre-defined maximum value. The matrix X and the matrix S with increased estimation accuracy are used to form an impairment co-variance matrix Ru estimate.
    Type: Grant
    Filed: April 20, 2010
    Date of Patent: November 25, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventor: Hai Wang
  • Publication number: 20140341260
    Abstract: Techniques for processing a received multi-code code-division multiple-access (CDMA) signal to detect unused spreading codes are disclosed. An example method includes, for each of a plurality of observation time intervals and for each of one or more candidate spreading codes, determining a detection threshold for use in detecting whether the candidate spreading code is unused in the received multi-code CDMA signal, based on a target detection sensitivity and at least one of an estimate of received signal quality and an estimate of channel estimation quality. Estimated signal power for the candidate spreading code is compared to estimated noise and interference power corresponding to a spreading code that is known to be unused or corresponding to a spreading code that carries known symbol values, using the calculated detection threshold. Whether or not the candidate spreading code is unused is then determined, based on the comparison.
    Type: Application
    Filed: May 20, 2013
    Publication date: November 20, 2014
    Applicant: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Andres Reial, Elias Jonsson