Noise Or Interference Elimination Patents (Class 455/114.2)
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Patent number: 7565119Abstract: A power amplifier pre-distortion calibration technique transmits two packets at different power levels for use in the calibration. As each packet is transmitted, it is received by the same device through a loop back path. The two received packets are then processed to develop the information needed to perform digital pre-distortion.Type: GrantFiled: December 28, 2006Date of Patent: July 21, 2009Assignee: Intel CorporationInventor: Emanuel Cohen
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Publication number: 20090168863Abstract: A calibration circuit measures the variation in a filter resistor within the analog domain of the envelope path of a polar transmitter and produces a digital value representative of that variation. A digital processor determines a digital control signal from the digital value that is used to compensate, in the digital domain of the envelope path, for the variation in the filter resistor in the analog domain.Type: ApplicationFiled: January 2, 2008Publication date: July 2, 2009Applicant: BROADCOM CORPORATIONInventors: Alireza Zolfaghari, Hooman Darabi, Henrik T. Jensen
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Publication number: 20090168921Abstract: The present invention relates to transmitter devices and transmission methods of transmitting a modulated GMSK- or EDGE-signal in a transmission system, wherein normally the pulse shaping follows the given rules of standards for these mobile radio systems. The amount of TX spectra in the adjacent TX channels is predetermined by these rules. A second filtering step is suggested to be introduced for attenuating predetermined unwanted spectra in the adjacent transmit channels. A second goal of this suggestion is to reduce spectra at adjacent TX channels also at cases of nonlinearity at the TX Power Amplifier of the RF transmitter Nothing must be changed in standards of mobile communication systems, for example GSM.Type: ApplicationFiled: December 12, 2006Publication date: July 2, 2009Applicant: NXP B.V.Inventor: Winfrid Birth
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Patent number: 7555266Abstract: Data is transmitted in a radio communication system having two or more base stations that are located in the network and having additional radio stations, which are each connected to one of the base stations via radio interfaces. At least one first base station has an antenna array with a multitude of antenna elements and with a signal processing device for the directional transmitting-receiving of data. The first base station temporally overlays data to a radio station, which is connected to the base station, for the transmission of data from an external base station to an external radio station connected thereto. The transmission of data from the first base station is also received from the external radio station. The objective is to reduce the amount of disturbance to the external radio station caused by transmissions from the base station in the downlink direction.Type: GrantFiled: May 22, 2001Date of Patent: June 30, 2009Assignee: Nokia Siemens Networks GmbH & Co. KGInventors: Martin Haardt, Christoph Mecklenbraeuker
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Publication number: 20090163154Abstract: A method for compensating signal distortions in multiple transmitting branches (3, 5; 43, 45, 46) entering a composite amplifier (1; 1?). According to the invention the method comprises the steps of: —providing (S1) one or more input signals (x) to the composite amplifier, —observing (S2) an output signal (z) from the composite amplifier ( 1; 1?) for each provided input signal; —deriving (S5) an error in each output signal (z) by comparing the output signal with an ideal output signal, said error being caused by said signal distortions; —deriving (S11) the individual contribution from each transmitting branch (3, 5; 43,45,46) to the error by utilising a composite amplifier model, said composite amplifier model comprising information about the contribution from each constituent amplifier (23, 25; 103a,103b,103c) to the output signal for each provided input signal: —compensating the signal distortions in the transmitting branches (3, 5; 43,45,46) accordingly.Type: ApplicationFiled: April 10, 2006Publication date: June 25, 2009Applicant: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)Inventors: Tony Fondén, Richard Hellberg, Mats Klingberg, Spendim Dalipi
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Patent number: 7548762Abstract: A system and method is provided for tuning a Global Positioning System (GPS) antenna matching circuit in a portable wireless communications device. The method includes accepting a first matching circuit tuning value, measuring satellite vehicle (SV) carrier-to-noise ratio (C/N) associated with the first tuning value and a first search time interval, measuring the SV C/N associated with a next tuning value, and selecting the tuning value associated with the highest SV C/N to tune the matching circuit. In one aspect, the method further includes comparing the SV C/N to a first minimum threshold. If the first tuning value SV C/N exceeds the first minimum threshold, then the method measures the SV C/N associated with the next tuning value. Otherwise, a default tuning value can be selected to tune the matching circuit.Type: GrantFiled: November 30, 2005Date of Patent: June 16, 2009Assignee: Kyocera CorporationInventors: Jorge Fabrega-Sanchez, Henry Chang, Srivatsan Veeraraghavan, Ammar Kitabi
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Patent number: 7548733Abstract: A method and apparatus are provided for enabling a transmitter to have a substantially linear magnitude response and a substantially linear phase response. The transmitter includes first and second power amplifier drivers (PADs) having respective first and second non-linear phase responses. The first non-linear phase response is based on a first bias applied to the first PAD, and the second non-linear phase response is based on a second bias applied to the second PAD. The first and second PADs are coupled in parallel to provide a combined substantially linear phase response. According to an embodiment, the first and second PADs have respective first and second average input capacitances. Signal swings about the first and second biases vary the respective first and second average input capacitances, which may be combined to provide a combined average input capacitance that is substantially insensitive to the signal swings about the first and second biases.Type: GrantFiled: March 31, 2005Date of Patent: June 16, 2009Assignee: Broadcom CorporationInventor: Meng-An Pan
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Publication number: 20090149140Abstract: Systems and methodologies are described that facilitate mitigation of interference in a wireless communication environment. Terminals can utilize interference information provided by neighboring sectors to adjust transmit power and reduce interference. Access points can provide two sets or types of interference information. The first type can be transmitted over a large coverage area, requiring significant overhead and limiting the transmission rate. Access points can also provide a second set or type of interference information directed at smaller coverage area, such as an area proximate to the edge of the supported sector. This second type of interference information can be utilized by terminals that include the access point within their active set. The second set of interference information can be provided at a higher rate than the first set due to decreased overhead requirements. Terminals can utilize both sets of interference information to adjust transmit power.Type: ApplicationFiled: January 4, 2007Publication date: June 11, 2009Inventors: Mohammad J. Borran, Aamod Khandekar, Avneesh Agrawal, Tingfang Ji
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Patent number: 7546137Abstract: A method for use in a RFID reader, the method comprising providing an output signal from an amplifier of a transmitter, attenuating the output signal via a step attenuator, detecting and comparing the attenuated output signal to a reference value, and adjusting power to the amplifier until the attenuated output signal is substantially equal to the reference value. The attenuated output signal drives a local oscillator signal of a receiver thereby canceling noise generated by the transmitter in the receiver.Type: GrantFiled: February 27, 2006Date of Patent: June 9, 2009Assignee: Sirit Technologies Inc.Inventors: Loek J. D'Hont, Bernard Barink
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Patent number: 7542736Abstract: Techniques to reduce signal amplitude peak-to-average ratio (PAR) in a wireless communications system are described. The apparatus may include a signal conditioning module to receive a baseband signal. The signal conditioning module may split the baseband signal along multiple paths, delay one or more of the paths, and combine the multiple paths to form a conditioned signal having lower signal amplitude PAR than the baseband signal. Other embodiments are described and claimed.Type: GrantFiled: July 26, 2005Date of Patent: June 2, 2009Assignee: M/A-Com, Inc.Inventor: Mohsen Sarraf
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Patent number: 7542737Abstract: A transconducting device includes at least one transistor having a control electrode for receiving an input signal whose frequency spectrum contains two different frequencies, an output electrode for delivering an output signal, and a third electrode. The transconducting device further includes a voltage source for delivering a DC reference voltage, and a feedback controller for feedback-controlling the voltage on the third electrode to the DC reference voltage using a negative feedback loop. The negative feedback loop includes resistive damping, connects the third electrode and the control electrode, and has an open-loop gain greater than unity at a frequency equal to the frequency separation between the two different frequencies.Type: GrantFiled: September 8, 2006Date of Patent: June 2, 2009Assignee: STMicroelectronics S.A.Inventors: Fabien Pousset, Frédéric Rivoirard
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Publication number: 20090137208Abstract: An output amplifier is provided for use in a bidirectional communications interface, for example, connecting a transmitter and a receiver to a transmission line. The output amplifier includes a differential amplifier pair connected to output circuitry. The differential amplifier pair receives differential data signal pairs from each of a transmission line and a transmitter. The output circuitry receives signals from the differential amplifier pair and, in response, forms single-ended output logic signals. The output amplifier suppresses electronic input noise throughput using an asymmetric transfer characteristic that offsets output signal logic levels with respect to input noise signal levels. The asymmetric transfer characteristic is produced by skewing a transfer characteristic of the differential amplifier pair using an asymmetrical transistor configuration at an output side of the differential amplifier pair.Type: ApplicationFiled: November 21, 2008Publication date: May 28, 2009Inventors: Gyudong Kim, Min-Kyu Kim
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Patent number: 7539475Abstract: Special DC tone treatment in a wireless communications system, e.g., an OFDM system, is discussed. In the downlink, a wireless terminal receiver introduces self-interference at the DC tone from the RF/baseband conversion. A base station every so often does not transmit on the downlink DC tone while continuing to transmit on other downlink tones. Wireless terminals measure received signal on the downlink DC tone during the time of suspended DC tone transmission, estimate self-interference and apply a correction to other received downlink DC tones. In the uplink DC tone interference is a composite of the assigned wireless terminal transmitter's baseband/RF conversion self-interference and air link noise. During one symbol interval of an N symbol interval dwell, the uplink DC tone is reserved for a special modulation symbol, which is a predetermined function of the other N?1 modulation symbols.Type: GrantFiled: September 16, 2005Date of Patent: May 26, 2009Assignee: QUALCOMM IncorporatedInventors: Rajiv Laroia, Junyi Li, Hui Jin
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Publication number: 20090124218Abstract: An RF transmitter (10) includes an RF amplifier (22) that experiences gain-droop distortion as a result of self-heating. A heat compensator (20) is included to insert a gain boost of an amount which is the inverse of the gain droop experienced by the RF amplifier (22). The amount of gain boost is determined by generating a heat signal (88) from low-pass filtering (86) the squared magnitude (82) of a communication signal (14). The heat signal (88) is scaled by a weighting signal (68) estimated by monitoring the amplified RF signal (42) at the output of the RF amplifier (22). A nonlinear relationship section (96) then transforms the scaled signal into a gain-boost signal (94) that corresponds to the inverse of gain droop in the RF amplifier (22).Type: ApplicationFiled: November 14, 2007Publication date: May 14, 2009Applicant: CRESTCOM, INC.Inventors: Ronald Duane McCallister, Eric M. Brombaugh
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Patent number: 7529316Abstract: A transmitter, that effectively suppresses a peak level of transmit signals, equipped with a peak reduction signal generating means that generates a peak reduction signal. A level of the peak reduction signal is based on a transmit signal level threshold for determining a peak of the transmit signal, and is based on a transmit signal peak level. Further, a phase of the peak reduction signal is based on the phase of the transmit signal. The transmitter is also equipped with a peak reduction signal processing means that subjects the peak reduction signal to band restriction and orthogonal modulation, and is equipped with a transmit signal level suppressing means that subtracts the peak reduction signal subjected to band restriction and orthogonal modulation from the transmit signal.Type: GrantFiled: September 15, 2004Date of Patent: May 5, 2009Assignee: Hitachi Kokusai Electric Inc.Inventors: Norio Hasegawa, Tetsuhiko Miyatani, Yoshihiko Akaiwa
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Publication number: 20090111398Abstract: There is provided an apparatus, having a first local oscillator generate a first oscillation signal, a first mixer generating a transmit signal by mixing an input signal and the first oscillation signal, an observation receiver receiving a portion of the transmit signal, and applying, in a first operation mode of the apparatus, the received portion of the transmit signal such that a transmit signal component on a frequency of the first oscillation signal falls into a band-pass frequency of the observation receiver, and shift, in a second operation mode of the apparatus, the received portion of the transmit signal such that an oscillation leakage signal component of the first oscillation signal falls into the band-pass frequency of the observation receiver; and a compensation unit generating a compensation signal based on the band-pass signal of the observation receiver for compensation of the input signal.Type: ApplicationFiled: August 11, 2008Publication date: April 30, 2009Inventors: Marko Leukkunen, Kauko Heinikoski
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Patent number: 7525942Abstract: A system and/or a method for detecting interference using correlation may be used in a communication system to protect against, or to report the presence of, narrowband interference, which has deleterious effects on the performance of the wideband communication system. The interference detection system described herein may be used to determine presence of narrowband interference by calculating correlation factors for a plurality of narrowband channels disposed within the wideband communication system and comparing the correlation factors with a threshold correlation factor.Type: GrantFiled: September 1, 2005Date of Patent: April 28, 2009Assignee: Isco International, Inc.Inventor: Sean S. Cordone
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Publication number: 20090097590Abstract: An RF transmitter (10) includes an RF amplifier (28) that generates an amplified RF signal (36) including a linear RF signal (92) and a spurious baseband signal (94). The spurious baseband signal (94) interacts with bias feed networks (56, 66) to cause the RF amplifier (28) to generate an unwanted RF distortion at or near the allocated RF bandwidth. A baseband compensation signal (98) is generated and equalized in an adaptive equalizer (102) then fed to the RF amplifier (28). A feedback signal (46) is obtained from the RF amplifier (28) and used to drive the adaptive equalizer (102). A feedback loop causes the adaptive equalizer to adjust a baseband signal (24, 32) supplied to the RF amplifier (28) so that the RF distortion is minimized.Type: ApplicationFiled: October 10, 2007Publication date: April 16, 2009Applicant: CRESTCOM, INC.Inventors: Ronald Duane McCallister, Eric M. Brombaugh
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Patent number: 7518459Abstract: A harmonic-rejection modulation device is provided, which includes a phase splitter, a low pass filter, and a modulator. Based on a square wave, the phase splitter generates a plurality of unfiltered local oscillating signals having phase angles of 0°, 30°, 90°, 120°, 180°, 210°, 270° and 300°, respectively. The low pass filter filters the high frequency components of the unfiltered local oscillating signals to generate a plurality of local oscillating signals having phase angles of 0°, 30°, 90°, 120°, 180°, 210°, 270° and 300°, respectively. The modulator modulates a baseband signal with the local oscillating signals, wherein the third harmonics of the local oscillating signals are eliminated by the modulation process of the modulator. The invention also provides a method of modulating a baseband signal.Type: GrantFiled: December 15, 2006Date of Patent: April 14, 2009Assignee: Via Technologies Inc.Inventors: Nean-Chu Cheng, Ying-Che Tseng, Sen-You Liu, Did-Min Shih
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Patent number: 7519129Abstract: A fixed wireless access communications system comprises an access point and a plurality of subscriber units. Each subscriber unit (502) contends for access to a communications channel to the access point by transmitting a contention word to the access point during a contention time slot. The contention word is predistorted to compensate for the channel impulse response of the transmission channel so that the access point can decode the contention words without using equalisation. A control unit (512), which may comprise a microprocessor, loads the predistorted contention word (a) into a memory (520) and causes the stored predistorted contention word (a) to be applied to a transmitter (508) during a contention time slot when the subscriber unit (502) wishes to request a transmission channel to transmit data to the access point.Type: GrantFiled: November 12, 2002Date of Patent: April 14, 2009Assignee: Cambridge Broadband Networks LimitedInventors: John David Porter, Stephen David Greaves, Malcolm Paul Sellars
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Patent number: 7515876Abstract: A rake receiver for processing a multi-path input signal received from a communications channel, wherein each multi-path component of the multi-path input signal comprises one or more symbols, comprises a plurality of fingers and a demodulator. Each of the plurality of fingers is adapted to receive the multi-path input signal and provide a sequence of input samples corresponding to a multi-path component of the multi-path input signal. The demodulator is adapted (i) during a single clock period, to receive and process one or more input samples corresponding to only one of the fingers, (ii) for each of the fingers, to accumulate multiple processed input samples to form a symbol, and (iii) to provide the formed symbols for all fingers.Type: GrantFiled: May 3, 2005Date of Patent: April 7, 2009Assignee: Agere Systems Inc.Inventor: Gongyu Zhou
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Patent number: 7515661Abstract: A transmitting apparatus, a transmitting method, a receiving apparatus, a receiving method, a transceiver, a communication apparatus and method, a recording medium, and a program in which high quality voice can be decoded. A cellular telephone outputs coded voice data and also supplies uncoded voice sample data to a switching center while a telephone call is not made. Based on voice data used for the previous calculation processing and newly input voice data, the switching center performs calculation processing for quality-improving data for improving the quality of voice to be output from a cellular telephone that receives the coded voice data. The switching center stores the optimal quality-improving data as a user information database in association with the cellular telephone. The cellular telephone decodes the coded voice data based on the optimal quality-improving data supplied from the switching center.Type: GrantFiled: July 11, 2003Date of Patent: April 7, 2009Assignee: Sony CorporationInventors: Tetsujiro Kondo, Hiroto Kimura, Tsutomu Watanabe, Masaaki Hattori, Gakuho Fukushi
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Publication number: 20090088092Abstract: A method of shaping signals intended for transmission via at least one antenna, each signal having a respective frequency spectrum and being for transmission via a respective antenna, comprises selecting at least one interference-reducing signal, each interference-reducing signal being such as to modify the signal frequency spectrum for the antenna or a respective one of the antennas to include a respective frequency notch at an interference band, and modifying the frequency spectra with the selected interference-reducing signal or signals, wherein the selection is subject to a constraint on at least one characteristic of the spectra as modifiedType: ApplicationFiled: September 22, 2008Publication date: April 2, 2009Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yue Wang, Justin Coon
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Patent number: 7512111Abstract: A time adjustment method, a time stamping method and a telecommunication system are provided. The invention is based on performing a power measurement in the base station on a signal generated in the base station, and providing the signal with time characteristics proportional to a time reference received in the base station. Embodiments of the invention enable accurate synchronization of a base station and precise positioning of mobile stations.Type: GrantFiled: July 2, 2003Date of Patent: March 31, 2009Assignee: Nokia CorporationInventor: Jouni Kauhanen
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Publication number: 20090081969Abstract: A digital FM transmitter has a digital controlled oscillator for generating a modulated RF carrier. A digital signal processor receives digital input samples and generates a modulating signal for input to the digital controlled oscillator. A bandpass filter for filters frequency components of the modulated carrier outside a predetermined frequency band and supplies the filtered modulated RF carrier to an antenna.Type: ApplicationFiled: September 10, 2008Publication date: March 26, 2009Applicant: ZARLINK SEMICONDUCTOR INC.Inventors: Slobodan Milijevic, Krste Mitric
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Publication number: 20090081970Abstract: Interference that occurs during wireless communication may be managed through the use of fractional reuse and other techniques. In some aspects fractional reuse may relate to HARQ interlaces, portions of a timeslot, frequency spectrum, and spreading codes. Interference may be managed through the use of a transmit power profile and/or an attenuation profile. Interference also may be managed through the use of power management-related techniques.Type: ApplicationFiled: September 17, 2008Publication date: March 26, 2009Applicant: QUALCOMM IncorporatedInventors: Mehmet Yavuz, Peter J. Black, Sanjiv Nanda
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Patent number: 7509101Abstract: Methods and apparatus for reducing the amount of leakage in a transmitter are disclosed. In one embodiment, a wireless transmitter is comprises: a divider providing a local oscillation (LO) signal, a plurality of mixers that receive the LO signal and receive a signal to be modulated, a summer coupled to the plurality of mixers, and a plurality of amplifiers serially coupled to the summer. The divider couples to a capacitor, a resistor, and a power supply and the resistor and the capacitor form a pole that attenuates the LO signal present on the power supply.Type: GrantFiled: April 28, 2004Date of Patent: March 24, 2009Assignee: Texas Instruments IncorporatedInventors: Abdellatif Bellaouar, Alan R. Holden, Sher J. Fang
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Patent number: 7505737Abstract: Disclosed is an apparatus for generating a stable clock signal having a Long term jitter noise removed therefrom. In a mobile communication terminal having a power management chip for converting a sinusoidal wave oscillated in a crystal into a clock signal of square wave, the sinusoidal wave is converted into a square wave clock signal by the stabilized driving power having no alternating current components, and thus a power noise of the square wave clock signal is removed. Then, the square wave clock signal having the power noise removed therefrom is outputted after a predetermined delay time. Accordingly, it is possible to supply the clock signal having the Long term jitter noise removed therefrom and synchronized to each device in the mobile communication terminal.Type: GrantFiled: January 5, 2006Date of Patent: March 17, 2009Assignee: Pantech & Curitel Communications, IncInventor: Book Sung Park
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Publication number: 20090068965Abstract: A system for an omni digital package for reducing interference may include a passive combiner and a transmit signal canceller. The passive combiner may be configured to combine at least two input frequencies to produce a combined signal. The transmit signal canceller may be configured to determine an interference frequency based on a combination of the at least two input frequencies. The transmit signal canceller may include a tap weight determiner configured to determine a weighting coefficient associated with the interference frequency, and a cancellation function configured to perform a cancellation operation to at least partially cancel the interference frequency from the combined signal based on the weighting coefficient.Type: ApplicationFiled: September 6, 2007Publication date: March 12, 2009Inventor: John Meredith Faulkner
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Patent number: 7499686Abstract: A mobile device is provided that includes a digit input that can be manipulated by a user's fingers or thumb, an air conduction microphone and an alternative sensor that provides an alternative sensor signal indicative of speech. Under some embodiments, the mobile device also includes a proximity sensor that provides a proximity signal indicative of the distance from the mobile device to an object. Under some embodiments, the signal from the air conduction microphone, the alternative sensor signal, and the proximity signal are used to form an estimate of a clean speech value. In further embodiments, a sound is produced through a speaker in the mobile device based on the amount of noise in the clean speech value. In other embodiments, the sound produced through the speaker is based on the proximity sensor signal.Type: GrantFiled: February 24, 2004Date of Patent: March 3, 2009Assignee: Microsoft CorporationInventors: Michael J. Sinclair, Xuedong David Huang, Zhengyou Zhang
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Patent number: 7496376Abstract: Outer loop power control (OLPC) method and apparatus for mobile communications systems which allow rapid adjustment of the target desired signal to interference ratio (SIRtarget) satisfying a target block error rate (BLERtarget). Specifically, the outer loop power control method proposed herein is termed “Outage-Based OLPC” and establishes that the target desired signal to interference ratio (SIRtarget) is given as the sum of two components: the first component (SIRoutage-tgt) is calculated by means of a dynamic adjusting function, for example, a neural network which makes a quality criterion based on outage probabilities correspond with one based on the target block error rate (BLERtarget), taking as input the fading margins associated with the different outage probabilities considered; the other component (SIRBLER-tgt) is that which acts to correct the possible deviations in the target block error rate (BLERtarget) due to the non-ideal behavior of the previous component (SIRoutage-tgt).Type: GrantFiled: December 1, 2005Date of Patent: February 24, 2009Assignee: T.O.P. Optimized Technologies, S.L.Inventors: Alfonso Campo Camacho, Miguel Blanco Carmona, Luis Mendo Tomas, José M Hernando Rabanos, Alvaro Lopez Medrano
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Patent number: 7493091Abstract: A transmission circuit operating at a high efficiency and a low distortion is provided. A signal generation section 11 generates a vector signal and an amplitude signal. A vector modulation section 13 performs vector modulation on the vector signal. An amplification section 15 amplifies the signal processed with the vector modulation. A signal processing section 12 performs predetermined signal processing on the amplitude signal and outputs the resultant signal. A regulator 14 controls a voltage to be supplied to the amplification section 15 based on the magnitude of the signal which is output from the signal processing section 12. The signal processing section 12 determines whether or not the amplitude signal exceeds a threshold value at an interval of a predetermined time period, selects a discrete value to be output based on the determination result, and outputs a signal having the selected discrete value.Type: GrantFiled: June 30, 2006Date of Patent: February 17, 2009Assignee: Panasonic CorporationInventors: Toru Matsuura, Hisashi Adachi, Kaoru Ishida
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Patent number: 7483711Abstract: The present invention increases the available spectrum in a wireless network by sharing existing allocated (and in-use) portions of the RF spectrum in a manner that will minimize the probability of interfering with existing legacy users. The invention provides interference temperature-adaptive waveforms, and a variety of physical and media access control protocols for generating waveforms based on measurement and characterization of the local spectrum. The invention measures the local spectrum at a receiving node, generates an optimal waveform profile specifying transmission parameters that will water-fill unused spectrum up to an interference limit without causing harmful interference to primary and legacy transmitters using the same frequency bands, and enables simultaneous transmit and receive modes at a multiplicity of transceivers in a wireless network.Type: GrantFiled: October 22, 2003Date of Patent: January 27, 2009Assignee: BBN Technologies CorpInventor: Jerry D. Burchfiel
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Publication number: 20090023404Abstract: A receiver 650 operates in close proximity to at least one other component 610, 611, 612 causing interferences in signals received by the receiver 650. It is determined (steps 2002; 2003) whether and at which frequency a higher harmonic of and/or an inter-modulation product with signals generated by the other component 610 causes interference in signals received by the receiver 650, based on information about signals generated by the other component 610, 611, 612. At least one characteristic of the receiver 650 is adjusted to diminish an influence by a determined interference.Type: ApplicationFiled: March 1, 2006Publication date: January 22, 2009Inventors: Marko Leinonen, Juha Valtanen, Seppo Rousu
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Publication number: 20090023403Abstract: In one embodiment, a method of controlling intermodulation (IM) interference is provided. The method comprises determining if an IM product spectrum overlaps the spectrum of an assigned receive frequency and determining when transmissions from at least two transmitters are to overlap in time. If the IM product spectrum overlaps the assigned receive frequency spectrum, it is determined if a signal is being propagated on the receive frequency when the transmissions from the at least two transmitters are to overlap in time.Type: ApplicationFiled: July 20, 2007Publication date: January 22, 2009Applicant: HONEYWELL INTERNATIONAL INC.Inventor: E.F. Charles LaBerge
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Patent number: 7480266Abstract: Apparatus and systems, as well as methods and articles, may operate to detect radio-frequency energy at a frequency associated with at least one wireless networking channel and to transmit a data frame responsive to determining that the radio-frequency energy is not associated with a wireless networking transmission.Type: GrantFiled: November 30, 2004Date of Patent: January 20, 2009Assignee: Intel CorporationInventors: Ravi A. Murty, Jr-Shian Tsai
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Patent number: 7477635Abstract: Techniques and structures are presented for use in mitigating the effects of platform noise within a wireless device.Type: GrantFiled: May 19, 2005Date of Patent: January 13, 2009Assignee: Intel CorporationInventors: Yongfang Guo, Xintian E. Lin, Qinghua Li
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Publication number: 20090011725Abstract: A radio receiver includes an aerial wire that receives a radio signal in which a transmission signal is superimposed on a carrier, a voltage-controlled oscillator that oscillates a local oscillation signal, a frequency multiplier, a demodulation circuit that demodulates the transmission signal on the basis of the radio signal and the local oscillation signal, and an oscillation frequency control circuit that repeatedly sweeps the frequency of the local oscillation signal over a frequency bandwidth that is equal to or greater than the width of a frequency drift in a carrier frequency from the aerial wire or over a frequency bandwidth that is equal to or greater than the width of a frequency drift in the local oscillation signal.Type: ApplicationFiled: September 3, 2008Publication date: January 8, 2009Applicant: MURATA MANUFACTURING CO., LTD.Inventor: Akira KATO
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Publication number: 20090011724Abstract: The radio telecommunication terminal (2) comprises a data burst scheduler able to schedule the continuous transmission of consecutive data bursts which generate noise of similar energy on the radio-frequency channel as long as a specific radio-frequency channel is used to receive a radio signal, the respective energy of the noise generated by the transmission of two consecutive first and second data burst being similar only if the noise energy gradient between the end of the transmission of the first data burst and the beginning of the transmission of the second data burst is situated between predetermined upper and lower limits.Type: ApplicationFiled: January 22, 2007Publication date: January 8, 2009Applicant: NXP B.V.Inventors: Jean-Philippe Perrin, Jean-Claude Bini
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Patent number: 7471934Abstract: A translational-loop transmitter includes a local oscillator (LO) generator for generating first and second LO signals, a modulator for generating a modulated reference signal using the second LO signal, and an offset phase-locked-loop (PLL) for phase-locking an output signal to the reference signal, and for tuning the output signal in accordance with the first LO signal. The PLL includes an offset mixer in a feedback path of the PLL, and operates in accordance with a frequency plan that minimizes the effects of on- and off-channel spurs at the output of the offset mixer.Type: GrantFiled: November 22, 2004Date of Patent: December 30, 2008Assignee: Broadcom CorporationInventors: Hong Shi, Frank Carr
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Patent number: 7460843Abstract: A quantizer 122, and a plurality of down-samplers 124-1 to 124-N down-sampling the quantized output at a speed of (1/N) of the sampling rate of the quantizer 122 and shifting the respective phases by (360/N) degrees so as to provide a latched output, are provided. As a result, it is possible to carry out the same operation as for a polyphase quantizer using the down-samplers 124-1 to 124-N with a small circuit scale, while avoiding the variations in characteristics that occur as a result of using a polyphase quantizer.Type: GrantFiled: March 17, 2006Date of Patent: December 2, 2008Assignee: Panasonic CorporationInventor: Taichi Ikedo
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Patent number: 7453954Abstract: The present invention is related to methods and apparatus that can advantageously reduce a peak to average signal level exhibited by single or by multicarrier multibearer waveforms. Embodiments of the invention further advantageously can manipulate the statistics of the waveform without expanding the spectral bandwidth of the allocated channels. Embodiments of the invention can be applied to either multiple carrier or single carrier systems to constrain an output signal within predetermined peak to average bounds. Advantageously, the techniques can be used to enhance the utilization of existing multicarrier RF transmitters, including those found in third generation cellular base stations. However, the peak to average power level managing techniques disclosed herein can apply to any band-limited communication system and any type of modulation. The techniques can apply to multiple signals and can apply to a wide variety of modulation schemes or combinations therof.Type: GrantFiled: April 26, 2006Date of Patent: November 18, 2008Assignee: PMC-Sierra, Inc.Inventors: Andrew S. Wright, Richard E. Ryan, Bartholomeus T. W. Klijsen, Denis John Peregrym, Brenda Davison
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Patent number: 7453934Abstract: The present invention provides a method for automatic calibration of a signal path in receivers (e.g., radio frequency receivers) using a noise (and not a specific test signal) as a source and a fast Fourier transform (FFT) of the noise for correcting various parameters related to an inphase/quadrature (I/Q) imbalance in a frequency domain. The present invention (method and apparatus) can provide detecting and correcting an I/Q phase error, an I/Q amplitude error, an absolute corner frequency of the analog baseband filter, and a relative corner frequency of the analog baseband filters just by using the noise as a stimuli. This calibration can be used for a factory calibration or it can be used as an on-site calibration for base stations. Mobile devices can calibrate themselves independently of their location. This reduces the requirements for the test equipment in the manufacturing and maintenance stages.Type: GrantFiled: June 27, 2005Date of Patent: November 18, 2008Assignee: Nokia CorporationInventors: Pauli Seppinen, Julius Koskela, Mikael Gustafsson
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Patent number: 7454178Abstract: A transmitter module of a wireless transmission system with at least one transmission path having a power amplifier disposed at the input side includes a low-pass filter disposed at the output side and an impedance converter disposed therebetween. The power amplifier and the low-pass filter are, thereby, disposed on the top surface of a multi-layer carrier substrate. Preferably, the impedance converter is disposed in metallization planes of the carrier substrate. The inventive integration of all of these components in one module especially allows for a step-wise impedance adaptation between the low-impedance amplifier output and the output of the transmitter module having a defined output impedance (e.g. 50 ohm), whereby the impedance adaptation is partially carried out by the low-pass filter. A multistage impedance adaptation allows for a reduction of, e.g., the length of the line sections used in the impedance converter and the signal losses involved.Type: GrantFiled: November 14, 2005Date of Patent: November 18, 2008Assignee: EPCOS AGInventors: Christian Block, Holger Flühr, Christian Hoffmann
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Patent number: 7450921Abstract: The invention provides a communication semiconductor integrated circuit (RF IC) that, when a transmission oscillator is incorporated into a semiconductor chip, secures the oscillation operation over a wide frequency range, prevents a deterioration of a transmission spectrum, and thereby enhances the accuracy of an oscillation frequency. The integrated circuit corrects a dispersion of the KV characteristic of the transmission oscillator by calibrating a current Icp of the charge pump inside the phase control loop. More in concrete, the integrated circuit measures a KV value Kv of the transmission oscillator, and calibrates the current Icp of the charge pump so that Kv·Icp falls into a predetermined value.Type: GrantFiled: January 11, 2007Date of Patent: November 11, 2008Assignee: Renesas Technology Corp.Inventors: Satoshi Arayashiki, Hirotaka Oosawa, Noriyuki Kurakami, Akira Okasaka, Yasuyuki Kimura, Toshiya Uozumi, Hirokazu Miyagawa, Satoshi Tanaka
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Publication number: 20080274707Abstract: Disclosed is a method and apparatus for managing transmit requests among a plurality of co-located transmitting devices each associated with a wireless transmitting protocol. The method comprises the steps of determining the cost associated with each of the transmit requests, wherein the cost is associated with the cost of granting the request and the cost of rejecting the request, granting the request associated with the lowest cost, and rejecting all other requests. In another aspect of the invention, the method comprises the step of determining whether the lowest cost is acceptable and rejecting the request associated with the lowest cost when the lowest cost is unacceptable.Type: ApplicationFiled: January 16, 2006Publication date: November 6, 2008Applicant: NXP B.V.Inventor: Stefan Drude
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Patent number: 7447483Abstract: The invention relates to a method and an arrangement for reducing interference in a radio apparatus. The solution comprises a clock signal generator, an analog part and a controller arranged to measure interference arising from the harmonic frequencies of the clock signal on the given radio channel, and a controller for controlling the pulse width of the clock signal on the basis of the measurement.Type: GrantFiled: February 11, 2004Date of Patent: November 4, 2008Assignee: Nokia CorporationInventor: Timo Väänänen
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Patent number: 7440741Abstract: A method and system for over-the-air testing of a radio transreceiver is described. The radio transreceiver is placed in an enclosure box that is shielded to prevent leakage of RF energy. A nest assembly holds in place the radio transreceiver during testing to provide repeatable results with different radios. The testing assembly allows high volume characterization of the radio transreceiver performance in an environment rich with interfering RF signals.Type: GrantFiled: September 19, 2002Date of Patent: October 21, 2008Assignee: Symbol Technologies, Inc.Inventors: James Comerford, Francisco Naranjo
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Patent number: 7440497Abstract: A multi-phase adaptive decision feedback equalizer minimizes post-cursor inter-symbol interference in a current data bit based on values of subsequent data bits in a data communication system. In one form, the receiver includes a plurality of modules each having a respective adaptive decision feedback equalizer. A processor responsive to output signals from each of the plurality of modules generates a plurality of coefficient values. The adaptive decision feedback equalizer has a plurality of taps receiving a respective output signal from one of the modules and a respective coefficient value to generate a respective correction signal. The correction signals are summed with the data signal and processed to recover the data. Pre-calculation of coefficients permits rapid selection of data. Multi-phase operation permits higher data frequencies.Type: GrantFiled: November 1, 2004Date of Patent: October 21, 2008Assignee: LSI CorporationInventors: Vishnu Balan, Joseph Caroselli, Jr., Ye Liu, Chintan M. Desai, Jenn-Gang Chern
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Patent number: 7440732Abstract: A transmitter includes a first mixer to generate a first output signal by up-converting a first baseband signal having a first DC offset component. A second mixer generates a second output signal by up-converting a second baseband signal having a second DC offset component. The second output signal is subtracted from the first output signal to generate a transmitter output signal. The transmitter output signal includes a local oscillator (LO) leakage signal caused by the first and/or second DC offset components. A third mixer produces a third output signal by up-converting the first DC offset component. A fourth mixer produces a fourth output signal by up-converting the second DC offset component. The fourth output signal is subtracted from the third output signal to generate a LO leakage cancellation signal. The LO leakage cancellation signal is subtracted from the transmitter output signal, thereby reducing a power of the LO leakage signal.Type: GrantFiled: August 26, 2005Date of Patent: October 21, 2008Assignee: Broadcom CorporationInventor: Meng-An Pan