Noise Or Interference Elimination Patents (Class 455/296)
  • Patent number: 8929846
    Abstract: Various electromagnetically-countered systems are provided and include at least one wave source irradiating harmful electromagnetic waves and at least one counter unit emitting counter electromagnetic waves for countering the harmful waves. Various generic counter units of such systems and various mechanisms are provided to counter the harmful waves by the counter units by matching configurations of the counter units with those of the wave sources, matching shapes of such counter waves with shapes of the harmful waves, etc. Various methods are provided for countering the harmful waves with the counter waves by such source or wave matching. Various methods are also provided for the counter units as well as counter waves. Various processes are provided for providing such systems and counter units. Various electric and/or magnetic shields may be used alone or in conjunction with such counter units to minimize irradiation of the harmful waves from the system.
    Type: Grant
    Filed: October 25, 2013
    Date of Patent: January 6, 2015
    Inventor: Youngtack Shim
  • Patent number: 8929847
    Abstract: A signal processing circuit with noise cancellation includes an impedance matching unit and a transconductance stage. The impedance matching unit is disposed at a first path, and arranged to provide input impedance matching, wherein the impedance matching unit is a passive element, and the first path is coupled between a signal input port and a signal output port. The transconductance stage is disposed at a second path, and arranged to guide circuit introduced noise to the signal output port for noise cancellation at the signal output port, wherein the second path is coupled between the signal input port and the signal output port.
    Type: Grant
    Filed: April 22, 2014
    Date of Patent: January 6, 2015
    Assignee: Mediatek Inc.
    Inventors: Yuan-Hung Chung, Yi-Shing Shih
  • Patent number: 8923793
    Abstract: A wireless communication device includes a demodulation unit which demodulates a predetermined reception frequency, an S/N improvement processing unit which performs an S/N improvement process on a demodulated signal output from the demodulation unit, a first filter which performs an adaptive operation with respect to a frequency having a largest amplitude in a signal output from the S/N improvement processing unit, and outputs a filter coefficient updated by the adaptive operation, a controller which calculates the frequency of the largest amplitude defined by the filter coefficient output from the first filter, and controls the demodulation unit to update the reception frequency so as to reduce a difference between the frequency having the largest amplitude and a predetermined frequency, and a second filter which limits a range of a frequency bandwidth of the demodulated signal based on the frequency having the largest amplitude.
    Type: Grant
    Filed: July 16, 2013
    Date of Patent: December 30, 2014
    Assignee: JVCKenwood Corporation
    Inventor: Yasunori Suzuki
  • Patent number: 8917792
    Abstract: A method (600) and apparatus (200) cancel odd-order distortion signals. Desensitization can be determined (610) in a received signal caused by odd-order harmonic distortion occurring from at least one transmit signal. A baseband replica harmonic distortion signal can be generated (620) using the transmit signal. The baseband replica harmonic distortion signal can be converted (630) to a low frequency harmonic distortion signal. The low frequency harmonic distortion signal can be subtracted (640) from the received signal to cancel the odd-order distortion from the received signal to create a corrected signal.
    Type: Grant
    Filed: December 12, 2012
    Date of Patent: December 23, 2014
    Assignee: Motorola Mobility LLC
    Inventors: Gregory R. Black, Dale G. Schwent
  • Publication number: 20140370822
    Abstract: Aspects of the disclosure can provide a circuit to be used in a device. The circuit includes a first receiver circuit, a second receiver circuit and a processing circuit. The first receiver circuit is configured to receive a first signal from an antenna that captures a combination of a target signal transmitted from another device to the device and an output signal driven by a transmitter in the device. The second receiver circuit is configured to receive a second signal generated based on to the output signal. The processing circuit is configured to cancel from the first signal noise due to the output signal based on the second signal.
    Type: Application
    Filed: June 13, 2013
    Publication date: December 18, 2014
    Inventors: Dennis MAHONEY, Wael AL-QAQ
  • Patent number: 8913702
    Abstract: The present invention discloses a type of LNB frequency down conversion integrated circuit. The present invention frequency-down-converts the RF signal with the Quadrature local oscillation signal (LO) and Quadrature Mixer. Then the 90 degree phase-shifting of the quadrature intermediate frequency (IF) signal after mixed is done by the use of passive Polyphase filter. The present invention further discloses a LNB frequency down conversion chip, a LNB frequency down circuit adopting the LNB frequency down conversion chip circuit and a method of LBN frequency down. The invention ensures the elimination of the minor image signal and the realization of the minor image suppression function.
    Type: Grant
    Filed: May 10, 2011
    Date of Patent: December 16, 2014
    Assignee: RDA Technologies Limited
    Inventors: Shunran Wei, Xunsong Yin
  • Publication number: 20140364077
    Abstract: RF communications circuitry, which includes a first RF filter structure and control circuitry, is disclosed. The first RF filter structure includes a pair of weakly coupled resonators and a first tunable RF filter. The control circuitry provides a first filter control signal. The first tunable RF filter receives and filters an upstream RF signal to provide a first filtered RF signal, such that a center frequency of the first tunable RF filter is based on the first filter control signal.
    Type: Application
    Filed: June 6, 2014
    Publication date: December 11, 2014
    Inventors: George Maxim, Dirk Robert Walter Leipold, Baker Scott
  • Patent number: 8909166
    Abstract: An apparatus and method for controlling a multi-band antenna in a mobile communication terminal are provided. An apparatus for controlling a multi-band antenna in a mobile communication terminal includes a modem, an antenna unit, a Radio Frequency (RF) processing unit, and a switch module. The modem outputs at least one control signal corresponding to a target frequency band. The antenna unit changes a resonance frequency of the antenna according to the at least one control signal. The RF processing unit includes a plurality of transmission/reception (TX/RX) paths and processes TX/RX signals. The switch module connects the antenna to one of the TX/RX paths according to the at least one control signal.
    Type: Grant
    Filed: June 28, 2011
    Date of Patent: December 9, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jung-Ho Park, Sung-Hwan Ko, Suk-Chan Hong, Young-Hwan Jung
  • 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: 8902831
    Abstract: Embodiments herein provide methods and systems for enhancing interference mitigation using conjugate symbol repetition and phase randomization on a set of subcarriers. The repeated data tone in the signal is complex-conjugated before transmission, when the repetition factor is two. When the repetition factor is greater than two, a combination of conjugate repetition and random/deterministic phase variation of the repeated tones is used to mitigate the interference mitigation. Embodiments further disclose Collision Free Interlaced Pilot PRU Structures that can be used with or without conjugate symbol repetition and phase randomization for interference mitigation.
    Type: Grant
    Filed: June 17, 2009
    Date of Patent: December 2, 2014
    Assignee: Centre of Excellence in Wireless Technology
    Inventors: Kiran Kumar Kuchi, Deviraj Klutto Milleth Jeniston, Vinod Ramaswamy, Baskaran Dhivagar, Krishnamurthi Giridhar, Bhaskar Ramamurthi, Padmanabhan Madampu Suryasarman, Dileep Manisseri Kalathil
  • Patent number: 8903320
    Abstract: A method wherein a message packet is received at a node in a 1st wireless communication system, wherein said 1st wireless communication system determines whether it is experiencing interference with a 2nd wireless communication system, and wherein said 1st wireless communication system takes action to reduce said interference. Reducing said interference might include reduction in signal strength, change in message coding, and other actions, in response to a set of selected interference thresholds. Different protocol effects might be changed in response to one or more said thresholds, with the effect that distinct wireless communication systems may operate in relatively close proximity with a minimum of interference.
    Type: Grant
    Filed: December 23, 2010
    Date of Patent: December 2, 2014
    Assignee: Meru Networks
    Inventors: Vaduvur Bharghavan, Mohan Ram
  • Patent number: 8903341
    Abstract: Certain aspects of the present disclosure provide ordering techniques for a Successive Interference Cancellation (SIC) receiver which may be used to robustly choose a correct stream for first decode under varying data rates, SNR and mobile propagation conditions in Multiple Input Multiple Output (MIMO) systems. The SIC ordering techniques discussed in the disclosure include SNR and/or Rate based information theoretic approach. For example, the SIC receiver may evaluate an SNR based or RATE-based information theoretic metric for the MIMO streams and choose one stream with a higher value of the metric for decoding first. A speculative single code block based approach is may also be used for selecting a stream for first decode, by leveraging the presence of per code block Cyclic Redundancy Check (CRC) and the lack of time diversity in LTE systems.
    Type: Grant
    Filed: December 5, 2012
    Date of Patent: December 2, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Supratik Bhattacharjee, Brian Clarke Banister
  • Publication number: 20140349590
    Abstract: A data transmission method includes transmitting an encoded data signal in form of a data stream of data bursts between a transmitter and a receiver, making a decision as a function of at least one data transmission parameter as to whether an interference treatment o the data signal to be transmitted will be performed in the transmitter or in the reciver, performing the interference treatment in terms of at least on code in the transmitter, and performing ther interference treatment of the data to be transmitted in terms of at least one further code in the reciver.
    Type: Application
    Filed: August 4, 2014
    Publication date: November 27, 2014
    Inventors: Frank KOWALEWSKI, Peter MANGOLD
  • 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: 8897403
    Abstract: A phased array antenna for providing a radiation pattern having at least one communication beam, includes a plurality of antenna elements, each with an antenna element signal having a phase relationship and an amplitude relationship to the other element signals; a digital signal processing arrangement providing a digital beamforming network; and an analog beamforming network arranged to reduce exposure of the digital signal processing arrangement to an interfering signal. Analog beamforming weights are selected to generate a null in the radiation pattern in a direction corresponding to the interfering signal.
    Type: Grant
    Filed: June 22, 2011
    Date of Patent: November 25, 2014
    Assignee: Astrium Limited
    Inventor: Simon John Stirland
  • Patent number: 8897732
    Abstract: Provided are a broadcast receiving apparatus which simultaneously receives a plurality of channels using a single tuner and tunes to a channel without affecting other channels when changing a channel, and a broadcast receiving method thereof. The broadcast receiving apparatus includes a radio frequency (RF) receiver receiving RF broadcast signals of a plurality of channels; an intermediate frequency (IF) converter converting the RF broadcast signals of the plurality of channels into IF signals, respectively; a plurality of signal processors separately processing and outputting the converted IF signals; a noise generator generating a noise signal corresponding to the IF signals; and a controller performing control to output the noise signal instead of the IF signals when at least one of the plurality of channels is changed according to user's input.
    Type: Grant
    Filed: November 6, 2012
    Date of Patent: November 25, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sang-min Lim, Yong-ho Choi, Kyoung-seok Noh
  • Patent number: 8891710
    Abstract: A method of channel estimation includes receiving a signal after transmission over a media having a plurality of sub-carriers in a frequency band. The signal is preprocessed including performing a fast Fourier transform (FFT) to generate a plurality of frequency-domain samples. Channel estimating is applied to the plurality of frequency-domain samples using (i) least squares (LS) estimation, wherein the LS estimation generates intermediate LS channel estimates for each of the sub-carriers, and (ii) frequency-domain filtering and scaling the intermediate LS channel estimates. The frequency-domain filtering uses a common frequency-domain filter consisting of a single filter coefficient vector having a plurality of frequency-domain filter coefficients to generate refined channel estimates for each of the plurality of sub-carriers.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: November 18, 2014
    Assignee: Texas Instruments Incorporated
    Inventor: June Chul Roh
  • Patent number: 8891700
    Abstract: Interference in a wireless network is detected by first applying during a detection stage a two-sample Kolmogorov-Smirnov (KS) test to samples obtained from a channel in the wireless network to obtain a KS statistic. When the KS statistic is larger than a predetermine threshold, it is determined that the samples include narrowband interference, and wideband otherwise.
    Type: Grant
    Filed: July 12, 2013
    Date of Patent: November 18, 2014
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Kyeong-Jin Kim, Philip Orlik, Ghulam M Bhatti
  • Patent number: 8891701
    Abstract: An electronic receiver may comprise nonlinear distortion modeling circuitry, interference estimation circuitry, and sequence estimation circuitry. The receiver may receive an orthogonal frequency division multiplexing (OFDM) symbol in the form of an electromagnetic signal. The nonlinear distortion modeling circuitry may generate a nonlinear distortion model that models nonlinear distortion introduced to the received electromagnetic signal en route to the sequence estimation circuitry. The interference estimation circuitry may estimate inter-subcarrier interference present in the received OFDM symbol based on the generated nonlinear distortion model. The estimating of the inter-subcarrier interference may comprise applying the nonlinear distortion model to one or more candidate vectors generated by the sequence estimation circuitry. The sequence estimation circuitry may sequentially process a plurality of received virtual subcarrier values of the OFDM symbol using the estimated inter-subcarrier interference.
    Type: Grant
    Filed: June 6, 2014
    Date of Patent: November 18, 2014
    Assignee: MagnaCom Ltd.
    Inventors: Amir Eliaz, Ilan Reuven
  • Publication number: 20140335812
    Abstract: A radio reception device and a radio receiving method are provided that, when a frequency band assigned to a different radio system is shared, can effectively suppress the influence of interfering waves from this different radio system.
    Type: Application
    Filed: November 8, 2012
    Publication date: November 13, 2014
    Inventor: Yasunori Futatsugi
  • Patent number: 8886150
    Abstract: The present invention discloses a narrow band interference detector for a receiver of a communication system. The narrow band interference detector includes a numerically-controlled oscillator (NCO), for generating an oscillating signal according to a time-variable frequency; a mixer, for mixing an input signal with the oscillating signal, to generate a mixed signal; a phase lock loop (PLL), for locking the mixed signal during a detection period according to the time-variable frequency; a first switch, for controlling a connection between the NCO and the PLL according to a desirable narrow band interference signal type of the at least one narrow band interference signal; and a narrow band determination unit, for determining at least one narrow band interference signal according to a low frequency component of the mixed signal, the time-variable frequency and the desirable narrow band interference signal type of the at least one narrow band interference signal.
    Type: Grant
    Filed: July 31, 2011
    Date of Patent: November 11, 2014
    Assignee: Mediatek Inc.
    Inventor: Wen-Sheng Hou
  • Patent number: 8886151
    Abstract: The present invention relates to a receiving device and method for removing a mismatch in a wireless communication system, and to a low noise amplifier (LNA) therefor. According to the present invention, the receiving method for removing the mismatch comprises the steps of: distinguishing the type of input signal received through a wireless network; controlling such that a common bias is applied to transistors within a low noise amplifier, if said input signal is a wideband signal; and outputting a signal from which said mismatch has been removed, by using a current mirror mode in which current paths within said low noise amplifier are crossed.
    Type: Grant
    Filed: August 11, 2011
    Date of Patent: November 11, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hee-Hyun Lee, Young-Jin Kim, Young-Min Ki
  • Patent number: 8884795
    Abstract: A reception device and corresponding method for maintaining a high dynamic range of an AD converter circuit and preventing excessive input to the AD converter circuit is disclosed. For example, a reception device includes a variable gain amplifier circuit that amplifies an input analog signal with a gain controlled by a predetermined control signal, an analog-to-digital converter circuit an overload detector circuit with the same frequency characteristic as the analog-to-digital converter circuit. The overload detector circuit outputs a signal according to a comparison between a level of a signal input to the analog-to-digital converter circuit and a predetermined threshold. The signal that lowers the gain of the variable gain amplifier circuit more greatly is selected out of the signal from the overload detector circuit and another signal, and the gain of the variable gain amplifier circuit is controlled on the basis of the selected signal.
    Type: Grant
    Filed: August 8, 2013
    Date of Patent: November 11, 2014
    Assignee: Sony Corporation
    Inventors: Yoshihisa Takaike, Hideki Yokoshima, Yuya Kondo, Tomohiro Matsumoto
  • Publication number: 20140329482
    Abstract: An apparatus for handling a received signal comprises a reception device, a mixer unit and a compensating unit. The reception unit can receive a received signal. The received signal has at least one signal component at a first frequency. Furthermore, the mixer unit can combine the received signal and a compensating signal using at least one active element in order to obtain a compensated received signal. In addition, the mixer unit can produce a mixer output signal on the basis of the compensated received signal and a local oscillator signal. In this case, the mixer output signal has a signal component, corresponding to the at least one signal component of the received signal, at a second frequency. The first frequency is higher than the second frequency.
    Type: Application
    Filed: April 25, 2014
    Publication date: November 6, 2014
    Inventor: CHRISTOPH WAGNER
  • Publication number: 20140329485
    Abstract: An example method of tactical communication is provided. The method includes receiving information indicating a tactical situation associated with a target area. The tactical situation is one of a missile in-flight, an eavesdropper, a signal jammer, and a transceiver located in a zone of interest. The method further includes performing a beamforming process including instructing transmission of a plurality of signaling beams from one or more transmitters toward the target area. The tactical situation may be associated with a foe and the plurality of signaling beams generate interference inhibiting communication with by the foe. The tactical situation may be associated with a friend and the plurality of signaling beams generate decodable signal for enhancing communication with the friend.
    Type: Application
    Filed: September 30, 2013
    Publication date: November 6, 2014
    Applicant: Alcatel-Lucent USA Inc.
    Inventors: Doru Calin, Aliye Ozge Kaya, Kai Yang, Simon Yiu
  • Publication number: 20140329484
    Abstract: Techniques for providing a jammer-resistant noise-cancelling receiver front end with band-pass impedance matching and good power efficiency. In an aspect, the center frequency of the band-pass impedance matching advantageously tracks the local oscillator frequency. In an aspect, first and second receive signal paths are provided, with an R-C network coupled to the output of the second receive signal path. The resistance of the R-C network may be selected to provide band-pass impedance matching to the RF input signal. The current outputs of the first and second signal paths are combined using a trans-impedance amplifier (TIA). In an aspect, the TIA may be implemented using a dual input transconductor amplifier to further optimize the noise performance and power efficiency features of the disclosure.
    Type: Application
    Filed: May 1, 2013
    Publication date: November 6, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Wing-fat A Lau, Hajir Hedayati, Vladimir Aparin
  • Patent number: 8880017
    Abstract: A system includes a transceiver configured to receive a composite signal. The composite signal is a composite of a transmit signal and a receive signal. A replica transmitter is configured to generate a replica transmit signal based on the transmit signal. A transmit canceller is configured to recover the receive signal at least in part by resistively summing the composite signal and the replica transmit signal.
    Type: Grant
    Filed: August 5, 2013
    Date of Patent: November 4, 2014
    Assignee: Marvell International Ltd.
    Inventors: Pierte Roo, Sehat Sutardja
  • Patent number: 8879461
    Abstract: Blank subframe link design uses reduced bandwidth either explicit or derived for Closed Subscriber Group (CSG) cell interference mitigation, enabling a non-allowed User Equipment (UE) to co-exist with CSG cells on the same carrier. One could specify UL blank subframes to orthogonalize non-allowed UE and allowed UE transmissions on UL either via explicit UL blank subframe definition or derived from DL blank subframe definition. Scheduling can orthogonalize data transmissions. A femto cell temporarily reducing uplink bandwidth can mitigate uplink control channel residual interference from a non-allowed UE. A relay configures RACH occasion to coincide with non-blank UL subframes as much as possible. UE knowledge of RACH occasion is sufficient to start RACH and hand over procedure. RACH occasions with 10 ms periodicity are supported by assigning all odd/even uplink HARQ interlaces to relay. RACH occasions with 20 ms periodicity are supported by assigning any of the 1/4 UL HARQ interlaces to relay.
    Type: Grant
    Filed: November 25, 2009
    Date of Patent: November 4, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Tingfang Ji, Peter Gaal
  • Patent number: 8880016
    Abstract: An anti-jamming system includes a tunable negative jamming signal feedback loop for feedback suppression of a received jamming signal. The system includes a zero IF phase locked loop (PLL) jamming signal receiver having a synchronous demodulator and a phase detector. A VCO is included in the PLL, as well as a phase detector and a loop filter. A replica jamming signal generator includes a tracking modulator with a baseband signal input coupled to an output of a synchronous demodulator in the receiver and a carrier input provided by the VCO. An output of the tracking modulator is negatively fed back to the input of the receiver to suppress the jamming signal in the received input.
    Type: Grant
    Filed: November 17, 2012
    Date of Patent: November 4, 2014
    Assignee: Semiconductor Ideas to the Market (ITOM) B.V.
    Inventor: Wolfdietrich Georg Kasperkovitz
  • Patent number: 8880071
    Abstract: A composite quality measure helps determine a target for a vertical handover between different connection types. Various measurements are normalized, weighted and summed to produce composite quality measures. A composite quality measure may be compared to a target value and the corresponding connection may be added to a feasibility table if the composite quality measure is above the target.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: November 4, 2014
    Assignee: Intel Corporation
    Inventors: Pouya Taaghol, Vivek Gupta
  • Patent number: 8879998
    Abstract: Disclosed is a device and method to automate the process of measuring RF noise, correlating measured noise with known sources, and making adjustments to the noise-measuring and reporting process. A wireless communication device is coupled to equipment at a fixed location, and transmits data about the operation of the equipment back to an operator, via a provider's network. Examples include fixed wireless terminals. A management entity aboard the wireless communication device performs the measurements via a transceiver and performs remedial actions when required, without requiring an onsite technician or remote assistance. The management entity may include a spectrum analyzer.
    Type: Grant
    Filed: May 2, 2014
    Date of Patent: November 4, 2014
    Assignee: AT&T Mobility II LLC
    Inventor: Scott D. Prather
  • Patent number: 8874061
    Abstract: A filtering apparatus and method for dual-band sensing circuit are disclosed. The invention features a dual-band sensing unit disposed in a filtering device that receives the signals from a sub-system with variable frequency spectrum. The signals are split up into several bands. After that, one or more frequency detecting units are used to detect the power of high-band and low-band signals, and convert the power into a voltage signal. Users can externally adjust the gain of a tunable gain amplifier for the voltage signal. Further, a comparison operation is processed by a comparator, and a signal resulted from the comparison operation is used to control the switch timing for an RF switching unit. Consequently, this like adaptive notch filter is achieved to determine the intensity of noise and thereby to turn on the high-band or low-band notch filters, so as to reduce the in-band loss.
    Type: Grant
    Filed: January 22, 2008
    Date of Patent: October 28, 2014
    Assignee: Azurewave Technologies, Inc.
    Inventors: Chung-Er Huang, Huang-Chan Chien
  • Patent number: 8874040
    Abstract: In an ad hoc peer-to-peer communication network between wireless devices, a high priory first receiver device is configured to perform successive interference cancellation (SIC). The first receiver device receives a first transmission request from a first transmitter device indicating that the first transmitter device intends to transmit traffic to the first receiver device. Similarly, the first receiver device receives a second transmission request from an interferer second transmitter device. The first receiver device then determines a transmission rate cap for the interferer second transmitter device based on the signal strengths of the first and second transmission requests and sends it to the interferer second transmitter device. The transmission rate cap is a maximum rate at which the first receiver device can reliably decode traffic signals from the second transmitter device.
    Type: Grant
    Filed: June 30, 2008
    Date of Patent: October 28, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Junyi Li, Rajiv Laroia, Saurabh Tavildar, Xinzhou Wu
  • Patent number: 8874175
    Abstract: In an embodiment, an apparatus includes a determiner, converter, adapter, and modifier. The determiner is configured to generate a representation of a difference between a first frequency at which a first signal is sampled and a second frequency at which a second signal is sampled, and the converter is configured to generate a second sample of the first signal at a second time in response to the representation and a first sample of the first signal at a first time. The adapter is configured to generate a sample of a modifier signal in response to the second sample of the first signal, and the modifier is configured to generate a modified sample of the second signal in response to a sample of the second signal and the sample of the modifier signal. For example, such an apparatus may be able to reduce the magnitude of an echo signal in a system having an audio pickup (e.g., a microphone) near an audio output (e.g., a speaker).
    Type: Grant
    Filed: November 8, 2012
    Date of Patent: October 28, 2014
    Assignee: STMicroelectronics Asia Pacific Pte. Ltd.
    Inventors: Karthik Muralidhar, Sapna George, Saurav Sahu, Frank Teo
  • Patent number: 8873683
    Abstract: A receiver circuit receives a signal including a first reference signal from a first antenna port that is allocated to the UE. The receiver circuit includes a descrambling and despreading unit that despreads and descrambles the signal using a spreading code of the first antenna port and a scrambling sequence assigned to the UE to generate a first antenna port signal. The descrambling and despreading unit despreads and descrambles the signal using a spreading code of a second antenna port and the scrambling sequence assigned to the UE, wherein the second antenna port is unallocated to the UE to generate a second antenna port signal. A channel estimator generates a channel estimate of the first antenna port based on the first antenna port signal. An estimation unit estimates an interference and noise covariance measure based on the first antenna port signal, the channel estimate and the second antenna port signal.
    Type: Grant
    Filed: December 7, 2012
    Date of Patent: October 28, 2014
    Assignee: Intel Mobile Communications GmbH
    Inventors: Rajarajan Balraj, Biljana Badic, Tobias Scholand
  • Patent number: 8874059
    Abstract: A method for reducing power consumption on a wireless communication device is described. The wireless communication device includes a first stage active filter and a second stage active filter. A condition measurement is obtained that includes a signal measurement condition. If it is determined that the condition measurement is above a threshold, the second stage active filter is bypassed.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: October 28, 2014
    Assignee: QUALCOMM, Incorporated
    Inventors: Li Liu, Steven C Ciccarelli, Shrenik Patel, Prasad Srinivasa Siva Gudem, Zixiang Yang, Frederic Bossu, Wu-Hsin Chen, Chiewcharn Narathong
  • Patent number: 8873651
    Abstract: An OFDM generation apparatus and methods for generating OFDM transmission signals from OFDM symbols, each including a plurality of OFDM subcarriers, for transmission in a multi-carrier data transmission system, is provided. The provided apparatus and method may use a selected mixing frequency for mixing complex time-domain samples of OFDM symbols from a baseband frequency up to a passband frequency to obtain OFDM transmission signals, wherein the mixing frequency is selected such that common phase rotations of the OFDM subcarriers of OFDM symbols with respect to adjacent OFDM symbols of the OFDM transmission signals are avoided or compensated after the mixing. Additional apparatuses and methods for avoidance or compensation of such common phase rotations are also provided.
    Type: Grant
    Filed: January 12, 2011
    Date of Patent: October 28, 2014
    Assignee: Sony Corporation
    Inventors: Nabil Muhammad, Lothar Stadelmeier, Joerg Robert
  • Patent number: 8868018
    Abstract: A system for cancellation of a reciprocal-mixing noise may comprise a down-converter mixer that may be configured to down convert a radio-frequency (RF) signal and to generate a baseband signal. The RF signal may include a desired signal and a blocker signal. A first signal path may be configured to receive the baseband signal and to generate a first signal. A second signal path may be configured to receive the baseband signal and to generate a second signal. A subtraction module may be configured to subtract the second signal from the first signal and to generate an output signal. The second signal may comprise the reciprocal-mixing noise, and the output signal may comprise the desired signal substantially free from the reciprocal-mixing noise.
    Type: Grant
    Filed: February 15, 2013
    Date of Patent: October 21, 2014
    Assignee: Broadcom Corporation
    Inventors: Mohyee Mikhemar, David Murphy, Ahmad Mirzaei, Hooman Darabi
  • Patent number: 8868007
    Abstract: Communication processing paths include distortions, such as DC offset in the baseband analog path which needs to be accounted for. The use of a digital-to-analog converter (DAC) to inject a DC offset cancellation signal can bring about noise/area/power advantages. The DAC is driven by a mixed signal low pass filter loop. However, the DAC could also be driven in an open loop system, or a combination of open and closed loop. A low noise sign and magnitude DAC with low area and power requirements is implemented using selectively connected programmable current sources to virtual earth input terminals on a transimpedance amplifier (TIA) op-amp circuit. The constant virtual earth voltage eliminates linearity problems that would otherwise exist due to the finite current source output impedance. Current sources are only switched in when required so unneeded sources are out of circuit and do not contribute noise or use any power.
    Type: Grant
    Filed: August 31, 2012
    Date of Patent: October 21, 2014
    Assignee: Broadcom Corporation
    Inventor: Andrew Terry
  • Patent number: 8867999
    Abstract: A method to mitigate interference in a wireless system is provided. The method includes processing a set of radio network identifiers and limiting a number of hypotheses associated with the radio network identifiers in order to mitigate interference in a wireless network. In another aspect, the method includes processing a set of hypotheses and limiting the set of hypotheses by limiting a number of downlink grants to a common space, limiting the number of downlink grants to a number of instances, or limiting the number of grants to a physical downlink control channel (PDCCH) type. In yet another aspect, the method includes processing a downlink set and generating a target termination level for the downlink data set, the termination level associated with a Hybrid automatic repeat-request.
    Type: Grant
    Filed: May 7, 2009
    Date of Patent: October 21, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Avneesh Agrawal, Peter Gaal, Ravi Palanki, Alexei Y. Gorokhov
  • Patent number: 8867671
    Abstract: A conversion circuit (20) for converting a complex analog input signal having an in-phase, I, component and a quadrature-phase, Q, component resulting from frequency down conversion of a radio-frequency, RF, signal (XRF) to a frequency band covering 0 Hz into a digital representation is disclosed. It comprises a channel-selection filter unit (40) arranged to filter the complex analog input signal, thereby generating a channel-filtered I and Q components, and one or more processing units (53, 53a-b). Each processing unit comprises four mixers (60-75) for generating a first and a second frequency-translated I component and a first and a second channel-filtered Q component based on two LO signals with equal LO frequency and a 90° mutual phase shift. Furthermore, each processing unit comprises a combiner unit (85, 120) for generating a first, a second, a third, and a fourth combined signal proportional to sums and differences between said frequency translated I and Q components.
    Type: Grant
    Filed: June 13, 2011
    Date of Patent: October 21, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Lars Sunström, Roland Strandberg
  • Patent number: 8867650
    Abstract: An apparatus and method for cross clock domain interference cancellation is provided to a communication system which includes a transmitter operated in a first clock domain and a receiver operated in a second clock domain. The apparatus comprises a First-In-First-Out (FIFO) circuit and a cancellation signal generator. The FIFO circuit receives a digital transmission signal of the transmitter in the first clock domain, and outputs the digital transmission signal in the second clock domain according to an accumulated timing difference between the first and second clock domains. The cancellation signal generator generates a cancellation signal for canceling an interference signal received by the receiver according to the digital transmission signal outputted by the FIFO circuit. The interference signal is generated in response to the digital transmission signal.
    Type: Grant
    Filed: February 14, 2012
    Date of Patent: October 21, 2014
    Assignee: Realtek Semiconductor Corp.
    Inventors: Liang-Wei Huang, Shieh-Hsing Kuo, Chi-Shun Weng, Chun-Hung Liu
  • Patent number: 8867647
    Abstract: A system is provided for transmitting a low code rate spatially multiplexed channel on multiple antennas. The system includes a transmitter and a processor. The processor is configured such that the processor encodes a block of information bits to form channel coded bits, wherein the ratio of the number of channel coded bits to the number of information bits is greater than one; and the processor maps the channel coded bits to modulation symbols, and each channel coded bit is mapped once to a modulation symbol. The transmitter is configured to transmit a first portion of the modulation symbols using a spreading sequence on a first antenna of the multiple antennas and to transmit a second portion of the modulation symbols using the spreading sequence on a second antenna of the multiple antennas.
    Type: Grant
    Filed: December 10, 2012
    Date of Patent: October 21, 2014
    Assignee: BlackBerry Limited
    Inventors: Robert Mark Harrison, Hua Xu, Andrew Mark Earnshaw, Zhijun Cai
  • Patent number: 8862087
    Abstract: A method for reciprocal-mixing noise cancellation may include receiving, from a first mixer, a first signal comprising a wanted signal at a first frequency and a modulated signal at a second frequency. The modulated signal may be a product of a reciprocal-mixing of an unwanted signal with a phase noise. One or more portions of the modulated signal may overlap the wanted signal, adding a reciprocal-mixing noise to the wanted signal. A second signal may be generated by mixing, at a second mixer, the first signal with a third signal, which is at a third frequency related to a blocker offset frequency. A gain may be applied to the second signal to generate an amplified second signal that may be subtracted from the first signal to generate a fourth signal. The fourth signal may be filtered to generate the wanted signal at the first frequency without the reciprocal-mixing noise.
    Type: Grant
    Filed: May 17, 2013
    Date of Patent: October 14, 2014
    Assignee: Broadcom Corporation
    Inventors: Mohyee Mikhemar, David Murphy, Hooman Darabi
  • Patent number: 8861641
    Abstract: A wireless communication device includes a mixer that multiplies quadrature-modulated transmission data by a local oscillation frequency signal and outputs a high-frequency signal; a distributor that distributes the high-frequency signal; a detector circuit that detects a direct current component included in the high-frequency signal, based on the high-frequency signal distributed by the distributor; a correction signal generating unit that generates a correction signal for removing the direct current component from the high-frequency signal, based on the direct current component detected by the detector circuit; a correction unit that corrects the high-frequency signal by the correction signal generated by the correction signal generating unit; and a transmission unit that transmits the high-frequency signal that has been corrected by the correction unit.
    Type: Grant
    Filed: January 7, 2011
    Date of Patent: October 14, 2014
    Assignee: NTT DoCoMo, Inc.
    Inventors: Shinya Oka, Takashi Okada
  • Patent number: 8855580
    Abstract: Circuits and methods are disclosed for reducing interference from transmitter leakage in a radio transceiver. An exemplary method for reducing interference from transmitter leakage in a radio transceiver comprises downconverting, filtering, and sampling a radio frequency signal comprising a desired signal and a transmitter leakage signal to obtain a sampled signal of interest. The method further comprises generating a sampled distortion signal estimate that estimates one or more distortion products of the transmitter leakage signal, such as a squared amplitude obtained from a square-law device or corresponding digital function. Finally, the method comprises combining the sampled distortion signal estimate with the sampled signal of interest to obtain interference-reduced signal samples.
    Type: Grant
    Filed: June 27, 2008
    Date of Patent: October 7, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Paul Wilkinson Dent, Sven Mattisson
  • Patent number: 8855567
    Abstract: In an ad hoc peer-to-peer communication network between wireless devices, a high priory first receiver device is configured to perform successive interference cancellation. A first pilot signal is received by the first receiver device from the first transmitter device. Similarly, a second pilot signal is received from a second transmitter device, the second pilot signal indicating that the second transmitter device intends to transmit a second traffic signal. The first receiver device determines a first and a second transmission rates for traffic transmissions from the first transmitter device. A control message is then transmitted by the first receiver device to the first transmitter device including the first and second transmission rates. Subsequently, the first receiver device wirelessly receives a traffic signal including a first traffic signal from the first transmitter device including a first and a second signal components generated from a first and a second codewords, respectively.
    Type: Grant
    Filed: June 30, 2008
    Date of Patent: October 7, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Junyi Li, Rajiv Laroia, Saurabh Tavildar, Xinzhou Wu
  • Patent number: 8855592
    Abstract: A method is disclosed for mitigating narrowband interference within a system for wideband communications. The method can include separating a wideband signal into a plurality of sub bands, detecting energy levels in the sub-bands, and activating a control signal if the energy levels of the sub-bands differ by a predetermined amount. Such a difference in energy levels can indicate that narrowband interference is present and interference mitigation features can be activated. In another embodiment, a system is disclosed that has a band splitter and a plurality of energy level detectors to detect energy differences in the sub bands. Other embodiments are also disclosed.
    Type: Grant
    Filed: May 27, 2008
    Date of Patent: October 7, 2014
    Assignee: Intel Corporation
    Inventors: Andrey V Belogolovy, Mikhail Lyakh, Alan E. Waltho, Anu Hannele Huttunen, Risto Kaunisto
  • Patent number: 8849197
    Abstract: In an ad hoc peer-to-peer communication network between wireless devices, a high priory first receiver device is configured to perform successive interference cancellation (SIC). The first receiver device sends a first rate report signal and a second rate report signal to a first transmitter device indicating a first and second transmission rates. A connection is established between the first transmitter device and the first receiver device in which the first receiver device is the intended receiver of traffic signals from the first transmitter device. The first receiver device receives a traffic signal in a subsequent traffic channel, the traffic signal including a first traffic signal from the first transmitter device having a first traffic transmission rate not exceeding the first transmission rate. The received traffic signal also includes a second traffic signal transmitted by an interfering second transmitter device having a second traffic transmission rate not exceeding the second transmission rate.
    Type: Grant
    Filed: June 30, 2008
    Date of Patent: September 30, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Junyi Li, Rajiv Laroia, Saurabh Tavildar, Xinzhou Wu
  • Patent number: 8849231
    Abstract: Systems and methods for adaptive power control are provided. In exemplary embodiments, a primary signal is received. A noise power level of the primary signal is then estimated. The noise power level may then be compared to at least one power threshold. Subsequently, a large power consuming system is controlled based on the comparison of the noise power level to the power threshold.
    Type: Grant
    Filed: August 8, 2008
    Date of Patent: September 30, 2014
    Assignee: Audience, Inc.
    Inventors: Carlo Murgia, Alex Afshar, David Klein